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* [musl] add loongarch64 port v3
@ 2022-05-05  3:21 王洪亮
  2022-05-09  1:34 ` [musl] " 王洪亮
  2022-05-16 14:27 ` [musl] " Rich Felker
  0 siblings, 2 replies; 13+ messages in thread
From: 王洪亮 @ 2022-05-05  3:21 UTC (permalink / raw)
  To: musl

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Hi,

I published loongarch64 port v3 in
https://github.com/loongson/musl/tree/loongarch-v2.0.

fixed two problem:

1.use __NR_clone3 in  __clone().

2.remove __NR_fstat and __NR_newfstatat.

please code review if there are any other problems ? thanks.


Hongliang Wang.


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From e952251efb2134e5c20ae8719a039a6e3c073d48 Mon Sep 17 00:00:00 2001
From: wanghongliang <wanghongliang@loongson.cn>
Date: Thu, 5 May 2022 02:44:07 +0800
Subject: [PATCH] add loongarch64 port v3.

Author: xiaojuanZhai <zhaixiaojuan@loongson.cn>
Author: meidanLi <limeidan@loongson.cn>
Author: guoqiChen <chenguoqi@loongson.cn>
Author: xiaolinZhao <zhaoxiaolin@loongson.cn>
Author: Fanpeng <fanpeng@loongson.cn>
Author: jiantaoShan <shanjiantao@loongson.cn>
Author: xuhuiQiang <qiangxuhui@loongson.cn>
Author: jingyunHua <huajingyun@loongson.cn>
Author: liuxue <liuxue@loongson.cn>
Author: wanghongliang <wanghongliang@loongson.cn

Signed-off-by: wanghongliang <wanghongliang@loongson.cn>
---
 arch/loongarch64/atomic_arch.h             |  53 ++++
 arch/loongarch64/bits/alltypes.h.in        |  18 ++
 arch/loongarch64/bits/fenv.h               |  20 ++
 arch/loongarch64/bits/float.h              |  16 ++
 arch/loongarch64/bits/hwcap.h              |  14 +
 arch/loongarch64/bits/posix.h              |   2 +
 arch/loongarch64/bits/ptrace.h             |   4 +
 arch/loongarch64/bits/reg.h                |  66 +++++
 arch/loongarch64/bits/setjmp.h             |   1 +
 arch/loongarch64/bits/signal.h             |  79 ++++++
 arch/loongarch64/bits/stat.h               |  18 ++
 arch/loongarch64/bits/stdint.h             |  20 ++
 arch/loongarch64/bits/syscall.h.in         | 303 +++++++++++++++++++++
 arch/loongarch64/bits/user.h               |   5 +
 arch/loongarch64/crt_arch.h                |  14 +
 arch/loongarch64/kstat.h                   |  21 ++
 arch/loongarch64/pthread_arch.h            |  13 +
 arch/loongarch64/reloc.h                   |  35 +++
 arch/loongarch64/syscall_arch.h            | 137 ++++++++++
 configure                                  |   1 +
 crt/loongarch64/crti.s                     |  15 +
 crt/loongarch64/crtn.s                     |  12 +
 include/elf.h                              |  66 +++++
 src/fenv/loongarch64/fenv.S                |  72 +++++
 src/ldso/loongarch64/dlsym.s               |  12 +
 src/setjmp/loongarch64/longjmp.S           |  37 +++
 src/setjmp/loongarch64/setjmp.S            |  34 +++
 src/signal/loongarch64/restore.s           |  10 +
 src/signal/loongarch64/sigsetjmp.s         |  29 ++
 src/thread/loongarch64/__set_thread_area.s |   7 +
 src/thread/loongarch64/__unmapself.s       |   7 +
 src/thread/loongarch64/clone.s             |  47 ++++
 src/thread/loongarch64/syscall_cp.s        |  29 ++
 33 files changed, 1217 insertions(+)
 create mode 100644 arch/loongarch64/atomic_arch.h
 create mode 100644 arch/loongarch64/bits/alltypes.h.in
 create mode 100644 arch/loongarch64/bits/fenv.h
 create mode 100644 arch/loongarch64/bits/float.h
 create mode 100644 arch/loongarch64/bits/hwcap.h
 create mode 100644 arch/loongarch64/bits/posix.h
 create mode 100644 arch/loongarch64/bits/ptrace.h
 create mode 100644 arch/loongarch64/bits/reg.h
 create mode 100644 arch/loongarch64/bits/setjmp.h
 create mode 100644 arch/loongarch64/bits/signal.h
 create mode 100644 arch/loongarch64/bits/stat.h
 create mode 100644 arch/loongarch64/bits/stdint.h
 create mode 100644 arch/loongarch64/bits/syscall.h.in
 create mode 100644 arch/loongarch64/bits/user.h
 create mode 100644 arch/loongarch64/crt_arch.h
 create mode 100644 arch/loongarch64/kstat.h
 create mode 100644 arch/loongarch64/pthread_arch.h
 create mode 100644 arch/loongarch64/reloc.h
 create mode 100644 arch/loongarch64/syscall_arch.h
 create mode 100644 crt/loongarch64/crti.s
 create mode 100644 crt/loongarch64/crtn.s
 create mode 100644 src/fenv/loongarch64/fenv.S
 create mode 100644 src/ldso/loongarch64/dlsym.s
 create mode 100644 src/setjmp/loongarch64/longjmp.S
 create mode 100644 src/setjmp/loongarch64/setjmp.S
 create mode 100644 src/signal/loongarch64/restore.s
 create mode 100644 src/signal/loongarch64/sigsetjmp.s
 create mode 100644 src/thread/loongarch64/__set_thread_area.s
 create mode 100644 src/thread/loongarch64/__unmapself.s
 create mode 100644 src/thread/loongarch64/clone.s
 create mode 100644 src/thread/loongarch64/syscall_cp.s

diff --git a/arch/loongarch64/atomic_arch.h b/arch/loongarch64/atomic_arch.h
new file mode 100644
index 00000000..bf4805c9
--- /dev/null
+++ b/arch/loongarch64/atomic_arch.h
@@ -0,0 +1,53 @@
+#define a_ll a_ll
+static inline int a_ll(volatile int *p)
+{
+	int v;
+	__asm__ __volatile__ (
+		"ll.w %0, %1"
+		: "=r"(v)
+		: "ZC"(*p));
+	return v;
+}
+
+#define a_sc a_sc
+static inline int a_sc(volatile int *p, int v)
+{
+	int r;
+	__asm__ __volatile__ (
+		"sc.w %0, %1"
+		: "=r"(r), "=ZC"(*p)
+		: "0"(v) : "memory");
+	return r;
+}
+
+#define a_ll_p a_ll_p
+static inline void *a_ll_p(volatile void *p)
+{
+	void *v;
+	__asm__ __volatile__ (
+		"ll.d %0, %1"
+		: "=r"(v)
+		: "ZC"(*(void *volatile *)p));
+	return v;
+}
+
+#define a_sc_p a_sc_p
+static inline int a_sc_p(volatile void *p, void *v)
+{
+	long r;
+	__asm__ __volatile__ (
+		"sc.d %0, %1"
+		: "=r"(r), "=ZC"(*(void *volatile *)p)
+		: "0"(v)
+		: "memory");
+	return r;
+}
+
+#define a_barrier a_barrier
+static inline void a_barrier()
+{
+	__asm__ __volatile__ ("dbar 0" : : : "memory");
+}
+
+#define a_pre_llsc a_barrier
+#define a_post_llsc a_barrier
diff --git a/arch/loongarch64/bits/alltypes.h.in b/arch/loongarch64/bits/alltypes.h.in
new file mode 100644
index 00000000..d1807aca
--- /dev/null
+++ b/arch/loongarch64/bits/alltypes.h.in
@@ -0,0 +1,18 @@
+#define _Addr long
+#define _Int64 long
+#define _Reg long
+
+#define __BYTE_ORDER 1234
+#define __LONG_MAX 0x7fffffffffffffffL
+
+#ifndef __cplusplus
+TYPEDEF int wchar_t;
+#endif
+
+TYPEDEF float float_t;
+TYPEDEF double double_t;
+
+TYPEDEF struct { long long __ll; long double __ld; } max_align_t;
+
+TYPEDEF unsigned nlink_t;
+TYPEDEF int blksize_t;
diff --git a/arch/loongarch64/bits/fenv.h b/arch/loongarch64/bits/fenv.h
new file mode 100644
index 00000000..264cafb5
--- /dev/null
+++ b/arch/loongarch64/bits/fenv.h
@@ -0,0 +1,20 @@
+#define FE_INEXACT    0x010000
+#define FE_UNDERFLOW  0x020000
+#define FE_OVERFLOW   0x040000
+#define FE_DIVBYZERO  0x080000
+#define FE_INVALID    0x100000
+
+#define FE_ALL_EXCEPT 0x1F0000
+
+#define FE_TONEAREST  0x000
+#define FE_TOWARDZERO 0x100
+#define FE_UPWARD     0x200
+#define FE_DOWNWARD   0x300
+
+typedef unsigned fexcept_t;
+
+typedef struct {
+	unsigned __cw;
+} fenv_t;
+
+#define FE_DFL_ENV ((const fenv_t *) -1)
diff --git a/arch/loongarch64/bits/float.h b/arch/loongarch64/bits/float.h
new file mode 100644
index 00000000..719c7908
--- /dev/null
+++ b/arch/loongarch64/bits/float.h
@@ -0,0 +1,16 @@
+#define FLT_EVAL_METHOD 0
+
+#define LDBL_TRUE_MIN 6.47517511943802511092443895822764655e-4966L
+#define LDBL_MIN 3.36210314311209350626267781732175260e-4932L
+#define LDBL_MAX 1.18973149535723176508575932662800702e+4932L
+#define LDBL_EPSILON 1.92592994438723585305597794258492732e-34L
+
+#define LDBL_MANT_DIG 113
+#define LDBL_MIN_EXP (-16381)
+#define LDBL_MAX_EXP 16384
+
+#define LDBL_DIG 33
+#define LDBL_MIN_10_EXP (-4931)
+#define LDBL_MAX_10_EXP 4932
+
+#define DECIMAL_DIG 36
diff --git a/arch/loongarch64/bits/hwcap.h b/arch/loongarch64/bits/hwcap.h
new file mode 100644
index 00000000..c9fa08f6
--- /dev/null
+++ b/arch/loongarch64/bits/hwcap.h
@@ -0,0 +1,14 @@
+/* HWCAP - Hardware Capabilities.
+ * Hardware information is not clear at present, leave it blank.
+ */
+#define HWCAP_LOONGARCH_CPUCFG	(1 << 0)
+#define HWCAP_LOONGARCH_FPU	(1 << 1)
+#define HWCAP_LOONGARCH_LSX	(1 << 2)  /* support 128bit vectors*/
+#define HWCAP_LOONGARCH_LASX	(1 << 3)  /* support 256bit vectors*/
+#define HWCAP_LOONGARCH_LBT	(1 << 4)  /* support LBT*/
+#define HWCAP_LOONGARCH_LVZ	(1 << 5)  /* support virtualization expansion*/
+#define HWCAP_LOONGARCH_CRC32	(1 << 7)  /* support CRC32 check*/
+#define HWCAP_LOONGARCH_AES	(1 << 6)
+#define HWCAP_LOONGARCH_SHA1	(1 << 8)
+#define HWCAP_LOONGARCH_SHA2	(1 << 9)
+#define HWCAP_LOONGARCH_SHA3	(1 << 10)
diff --git a/arch/loongarch64/bits/posix.h b/arch/loongarch64/bits/posix.h
new file mode 100644
index 00000000..8068ce98
--- /dev/null
+++ b/arch/loongarch64/bits/posix.h
@@ -0,0 +1,2 @@
+#define _POSIX_V6_LP64_OFF64 1
+#define _POSIX_V7_LP64_OFF64 1
diff --git a/arch/loongarch64/bits/ptrace.h b/arch/loongarch64/bits/ptrace.h
new file mode 100644
index 00000000..741fc668
--- /dev/null
+++ b/arch/loongarch64/bits/ptrace.h
@@ -0,0 +1,4 @@
+#define PTRACE_GET_THREAD_AREA	25
+#define PTRACE_SET_THREAD_AREA	26
+#define PTRACE_GET_WATCH_REGS	0xd0
+#define PTRACE_SET_WATCH_REGS	0xd1
diff --git a/arch/loongarch64/bits/reg.h b/arch/loongarch64/bits/reg.h
new file mode 100644
index 00000000..5d3f92c5
--- /dev/null
+++ b/arch/loongarch64/bits/reg.h
@@ -0,0 +1,66 @@
+#undef __WORDSIZE
+#define __WORDSIZE 64
+#define LOONGARCH64_EF_R0   0
+#define LOONGARCH64_EF_R1   1
+#define LOONGARCH64_EF_R2   2
+#define LOONGARCH64_EF_R3   3
+#define LOONGARCH64_EF_R4   4
+#define LOONGARCH64_EF_R5   5
+#define LOONGARCH64_EF_R6   6
+#define LOONGARCH64_EF_R7   7
+#define LOONGARCH64_EF_R8   8
+#define LOONGARCH64_EF_R9   9
+#define LOONGARCH64_EF_R10    10
+#define LOONGARCH64_EF_R11    11
+#define LOONGARCH64_EF_R12    12
+#define LOONGARCH64_EF_R13    13
+#define LOONGARCH64_EF_R14    14
+#define LOONGARCH64_EF_R15    15
+#define LOONGARCH64_EF_R16    16
+#define LOONGARCH64_EF_R17    17
+#define LOONGARCH64_EF_R18    18
+#define LOONGARCH64_EF_R19    19
+#define LOONGARCH64_EF_R20    20
+#define LOONGARCH64_EF_R21    21
+#define LOONGARCH64_EF_R22    22
+#define LOONGARCH64_EF_R23    23
+#define LOONGARCH64_EF_R24    24
+#define LOONGARCH64_EF_R25    25
+#define LOONGARCH64_EF_R26    26
+#define LOONGARCH64_EF_R27    27
+#define LOONGARCH64_EF_R28    28
+#define LOONGARCH64_EF_R29    29
+#define LOONGARCH64_EF_R30    30
+#define LOONGARCH64_EF_R31    31
+
+#define LOONGARCH64_EF_SIZE   304 /* size in bytes */
+
+#define EF_R0     LOONGARCH64_EF_R0
+#define EF_R1     LOONGARCH64_EF_R1
+#define EF_R2     LOONGARCH64_EF_R2
+#define EF_R3     LOONGARCH64_EF_R3
+#define EF_R4     LOONGARCH64_EF_R4
+#define EF_R5     LOONGARCH64_EF_R5
+#define EF_R6     LOONGARCH64_EF_R6
+#define EF_R7     LOONGARCH64_EF_R7
+#define EF_R8     LOONGARCH64_EF_R8
+#define EF_R9     LOONGARCH64_EF_R9
+#define EF_R10      LOONGARCH64_EF_R10
+#define EF_R11      LOONGARCH64_EF_R11
+#define EF_R12      LOONGARCH64_EF_R12
+#define EF_R13      LOONGARCH64_EF_R13
+#define EF_R14      LOONGARCH64_EF_R14
+#define EF_R15      LOONGARCH64_EF_R15
+#define EF_R16      LOONGARCH64_EF_R16
+#define EF_R17      LOONGARCH64_EF_R17
+#define EF_R18      LOONGARCH64_EF_R18
+#define EF_R19      LOONGARCH64_EF_R19
+#define EF_R20      LOONGARCH64_EF_R20
+#define EF_R21      LOONGARCH64_EF_R21
+#define EF_R22      LOONGARCH64_EF_R22
+#define EF_R23      LOONGARCH64_EF_R23
+#define EF_R24      LOONGARCH64_EF_R24
+#define EF_R25      LOONGARCH64_EF_R25
+#define EF_R26      LOONGARCH64_EF_R26
+#define EF_R27      LOONGARCH64_EF_R27
+#define EF_R28      LOONGARCH64_EF_R28
diff --git a/arch/loongarch64/bits/setjmp.h b/arch/loongarch64/bits/setjmp.h
new file mode 100644
index 00000000..f4a7f8a3
--- /dev/null
+++ b/arch/loongarch64/bits/setjmp.h
@@ -0,0 +1 @@
+typedef unsigned long long __jmp_buf[22];
diff --git a/arch/loongarch64/bits/signal.h b/arch/loongarch64/bits/signal.h
new file mode 100644
index 00000000..e6613516
--- /dev/null
+++ b/arch/loongarch64/bits/signal.h
@@ -0,0 +1,79 @@
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+
+#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#define MINSIGSTKSZ 4096
+#define SIGSTKSZ 16384
+#endif
+
+typedef unsigned long greg_t, gregset_t[32];
+
+typedef struct sigcontext {
+	unsigned long pc;
+	gregset_t gregs;
+	unsigned int flags;
+	unsigned long extcontext[0] __attribute__((__aligned__(16)));
+}mcontext_t;
+
+struct sigaltstack {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+};
+
+typedef struct __ucontext
+{
+	unsigned long uc_flags;
+	struct __ucontext *uc_link;
+	stack_t uc_stack;
+	sigset_t uc_sigmask;
+	mcontext_t uc_mcontext;
+} ucontext_t;
+
+#define SA_NOCLDSTOP  1
+#define SA_NOCLDWAIT  2
+#define SA_SIGINFO    4
+#define SA_ONSTACK    0x08000000
+#define SA_RESTART    0x10000000
+#define SA_NODEFER    0x40000000
+#define SA_RESETHAND  0x80000000
+#define SA_RESTORER   0x04000000
+
+#endif
+
+#define SIGHUP           1
+#define SIGINT           2
+#define SIGQUIT          3
+#define SIGILL           4
+#define SIGTRAP          5
+#define SIGABRT          6
+#define SIGIOT           SIGABRT
+#define SIGBUS           7
+#define SIGFPE           8
+#define SIGKILL          9
+#define SIGUSR1         10
+#define SIGSEGV         11
+#define SIGUSR2         12
+#define SIGPIPE         13
+#define SIGALRM         14
+#define SIGTERM         15
+#define SIGSTKFLT       16
+#define SIGCHLD         17
+#define SIGCONT         18
+#define SIGSTOP         19
+#define SIGTSTP         20
+#define SIGTTIN         21
+#define SIGTTOU         22
+#define SIGURG          23
+#define SIGXCPU         24
+#define SIGXFSZ         25
+#define SIGVTALRM       26
+#define SIGPROF         27
+#define SIGWINCH        28
+#define SIGIO           29
+#define SIGPOLL         SIGIO
+#define SIGPWR          30
+#define SIGSYS          31
+#define SIGUNUSED       SIGSYS
+
+#define _NSIG 65
diff --git a/arch/loongarch64/bits/stat.h b/arch/loongarch64/bits/stat.h
new file mode 100644
index 00000000..b7f4221b
--- /dev/null
+++ b/arch/loongarch64/bits/stat.h
@@ -0,0 +1,18 @@
+struct stat {
+	dev_t st_dev;
+	ino_t st_ino;
+	mode_t st_mode;
+	nlink_t st_nlink;
+	uid_t st_uid;
+	gid_t st_gid;
+	dev_t st_rdev;
+	unsigned long __pad;
+	off_t st_size;
+	blksize_t st_blksize;
+	int __pad2;
+	blkcnt_t st_blocks;
+	struct timespec st_atim;
+	struct timespec st_mtim;
+	struct timespec st_ctim;
+	unsigned __unused[2];
+};
diff --git a/arch/loongarch64/bits/stdint.h b/arch/loongarch64/bits/stdint.h
new file mode 100644
index 00000000..1bb147f2
--- /dev/null
+++ b/arch/loongarch64/bits/stdint.h
@@ -0,0 +1,20 @@
+typedef int32_t int_fast16_t;
+typedef int32_t int_fast32_t;
+typedef uint32_t uint_fast16_t;
+typedef uint32_t uint_fast32_t;
+
+#define INT_FAST16_MIN  INT32_MIN
+#define INT_FAST32_MIN  INT32_MIN
+
+#define INT_FAST16_MAX  INT32_MAX
+#define INT_FAST32_MAX  INT32_MAX
+
+#define UINT_FAST16_MAX UINT32_MAX
+#define UINT_FAST32_MAX UINT32_MAX
+
+#define INTPTR_MIN      INT64_MIN
+#define INTPTR_MAX      INT64_MAX
+#define UINTPTR_MAX     UINT64_MAX
+#define PTRDIFF_MIN     INT64_MIN
+#define PTRDIFF_MAX     INT64_MAX
+#define SIZE_MAX        UINT64_MAX
diff --git a/arch/loongarch64/bits/syscall.h.in b/arch/loongarch64/bits/syscall.h.in
new file mode 100644
index 00000000..689ff36b
--- /dev/null
+++ b/arch/loongarch64/bits/syscall.h.in
@@ -0,0 +1,303 @@
+#define __NR_io_setup                   0
+#define __NR_io_destroy                 1
+#define __NR_io_submit                  2
+#define __NR_io_cancel                  3
+#define __NR_io_getevents               4
+#define __NR_setxattr                   5
+#define __NR_lsetxattr                  6
+#define __NR_fsetxattr                  7
+#define __NR_getxattr                   8
+#define __NR_lgetxattr                  9
+#define __NR_fgetxattr                  10
+#define __NR_listxattr                  11
+#define __NR_llistxattr                 12
+#define __NR_flistxattr                 13
+#define __NR_removexattr                14
+#define __NR_lremovexattr               15
+#define __NR_fremovexattr               16
+#define __NR_getcwd                     17
+#define __NR_lookup_dcookie             18
+#define __NR_eventfd2                   19
+#define __NR_epoll_create1              20
+#define __NR_epoll_ctl                  21
+#define __NR_epoll_pwait                22
+#define __NR_dup                        23
+#define __NR_dup3                       24
+#define __NR3264_fcntl                  25
+#define __NR_inotify_init1              26
+#define __NR_inotify_add_watch          27
+#define __NR_inotify_rm_watch           28
+#define __NR_ioctl                      29
+#define __NR_ioprio_set                 30
+#define __NR_ioprio_get                 31
+#define __NR_flock                      32
+#define __NR_mknodat                    33
+#define __NR_mkdirat                    34
+#define __NR_unlinkat                   35
+#define __NR_symlinkat                  36
+#define __NR_linkat                     37
+#define __NR_umount2                    39
+#define __NR_mount                      40
+#define __NR_pivot_root                 41
+#define __NR_nfsservctl                 42
+#define __NR3264_statfs                 43
+#define __NR3264_fstatfs                44
+#define __NR3264_truncate               45
+#define __NR3264_ftruncate              46
+#define __NR_fallocate                  47
+#define __NR_faccessat                  48
+#define __NR_chdir                      49
+#define __NR_fchdir                     50
+#define __NR_chroot                     51
+#define __NR_fchmod                     52
+#define __NR_fchmodat                   53
+#define __NR_fchownat                   54
+#define __NR_fchown                     55
+#define __NR_openat                     56
+#define __NR_close                      57
+#define __NR_vhangup                    58
+#define __NR_pipe2                      59
+#define __NR_quotactl                   60
+#define __NR_getdents64                 61
+#define __NR3264_lseek                  62
+#define __NR_read                       63
+#define __NR_write                      64
+#define __NR_readv                      65
+#define __NR_writev                     66
+#define __NR_pread64                    67
+#define __NR_pwrite64                   68
+#define __NR_preadv                     69
+#define __NR_pwritev                    70
+#define __NR3264_sendfile               71
+#define __NR_pselect6                   72
+#define __NR_ppoll                      73
+#define __NR_signalfd4                  74
+#define __NR_vmsplice                   75
+#define __NR_splice                     76
+#define __NR_tee                        77
+#define __NR_readlinkat                 78
+#define __NR_sync                       81
+#define __NR_fsync                      82
+#define __NR_fdatasync                  83
+#define __NR_sync_file_range            84
+#define __NR_timerfd_create             85
+#define __NR_timerfd_settime            86
+#define __NR_timerfd_gettime            87
+#define __NR_utimensat                  88
+#define __NR_acct                       89
+#define __NR_capget                     90
+#define __NR_capset                     91
+#define __NR_personality                92
+#define __NR_exit                       93
+#define __NR_exit_group                 94
+#define __NR_waitid                     95
+#define __NR_set_tid_address            96
+#define __NR_unshare                    97
+#define __NR_futex                      98
+#define __NR_set_robust_list            99
+#define __NR_get_robust_list            100
+#define __NR_nanosleep                  101
+#define __NR_getitimer                  102
+#define __NR_setitimer                  103
+#define __NR_kexec_load                 104
+#define __NR_init_module                105
+#define __NR_delete_module              106
+#define __NR_timer_create               107
+#define __NR_timer_gettime              108
+#define __NR_timer_getoverrun           109
+#define __NR_timer_settime              110
+#define __NR_timer_delete               111
+#define __NR_clock_settime              112
+#define __NR_clock_gettime              113
+#define __NR_clock_getres               114
+#define __NR_clock_nanosleep            115
+#define __NR_syslog                     116
+#define __NR_ptrace                     117
+#define __NR_sched_setparam             118
+#define __NR_sched_setscheduler         119
+#define __NR_sched_getscheduler         120
+#define __NR_sched_getparam             121
+#define __NR_sched_setaffinity          122
+#define __NR_sched_getaffinity          123
+#define __NR_sched_yield                124
+#define __NR_sched_get_priority_max     125
+#define __NR_sched_get_priority_min     126
+#define __NR_sched_rr_get_interval      127
+#define __NR_restart_syscall            128
+#define __NR_kill                       129
+#define __NR_tkill                      130
+#define __NR_tgkill                     131
+#define __NR_sigaltstack                132
+#define __NR_rt_sigsuspend              133
+#define __NR_rt_sigaction               134
+#define __NR_rt_sigprocmask             135
+#define __NR_rt_sigpending              136
+#define __NR_rt_sigtimedwait            137
+#define __NR_rt_sigqueueinfo            138
+#define __NR_rt_sigreturn               139
+#define __NR_setpriority                140
+#define __NR_getpriority                141
+#define __NR_reboot                     142
+#define __NR_setregid                   143
+#define __NR_setgid                     144
+#define __NR_setreuid                   145
+#define __NR_setuid                     146
+#define __NR_setresuid                  147
+#define __NR_getresuid                  148
+#define __NR_setresgid                  149
+#define __NR_getresgid                  150
+#define __NR_setfsuid                   151
+#define __NR_setfsgid                   152
+#define __NR_times                      153
+#define __NR_setpgid                    154
+#define __NR_getpgid                    155
+#define __NR_getsid                     156
+#define __NR_setsid                     157
+#define __NR_getgroups                  158
+#define __NR_setgroups                  159
+#define __NR_uname                      160
+#define __NR_sethostname                161
+#define __NR_setdomainname              162
+#define __NR_getrlimit                  163
+#define __NR_setrlimit                  164
+#define __NR_getrusage                  165
+#define __NR_umask                      166
+#define __NR_prctl                      167
+#define __NR_getcpu                     168
+#define __NR_gettimeofday               169
+#define __NR_settimeofday               170
+#define __NR_adjtimex                   171
+#define __NR_getpid                     172
+#define __NR_getppid                    173
+#define __NR_getuid                     174
+#define __NR_geteuid                    175
+#define __NR_getgid                     176
+#define __NR_getegid                    177
+#define __NR_gettid                     178
+#define __NR_sysinfo                    179
+#define __NR_mq_open                    180
+#define __NR_mq_unlink                  181
+#define __NR_mq_timedsend               182
+#define __NR_mq_timedreceive            183
+#define __NR_mq_notify                  184
+#define __NR_mq_getsetattr              185
+#define __NR_msgget                     186
+#define __NR_msgctl                     187
+#define __NR_msgrcv                     188
+#define __NR_msgsnd                     189
+#define __NR_semget                     190
+#define __NR_semctl                     191
+#define __NR_semtimedop                 192
+#define __NR_semop                      193
+#define __NR_shmget                     194
+#define __NR_shmctl                     195
+#define __NR_shmat                      196
+#define __NR_shmdt                      197
+#define __NR_socket                     198
+#define __NR_socketpair                 199
+#define __NR_bind                       200
+#define __NR_listen                     201
+#define __NR_accept                     202
+#define __NR_connect                    203
+#define __NR_getsockname                204
+#define __NR_getpeername                205
+#define __NR_sendto                     206
+#define __NR_recvfrom                   207
+#define __NR_setsockopt                 208
+#define __NR_getsockopt                 209
+#define __NR_shutdown                   210
+#define __NR_sendmsg                    211
+#define __NR_recvmsg                    212
+#define __NR_readahead                  213
+#define __NR_brk                        214
+#define __NR_munmap                     215
+#define __NR_mremap                     216
+#define __NR_add_key                    217
+#define __NR_request_key                218
+#define __NR_keyctl                     219
+#define __NR_clone                      220
+#define __NR_execve                     221
+#define __NR3264_mmap                   222
+#define __NR3264_fadvise64              223
+#define __NR_swapon                     224
+#define __NR_swapoff                    225
+#define __NR_mprotect                   226
+#define __NR_msync                      227
+#define __NR_mlock                      228
+#define __NR_munlock                    229
+#define __NR_mlockall                   230
+#define __NR_munlockall                 231
+#define __NR_mincore                    232
+#define __NR_madvise                    233
+#define __NR_remap_file_pages           234
+#define __NR_mbind                      235
+#define __NR_get_mempolicy              236
+#define __NR_set_mempolicy              237
+#define __NR_migrate_pages              238
+#define __NR_move_pages                 239
+#define __NR_rt_tgsigqueueinfo          240
+#define __NR_perf_event_open            241
+#define __NR_accept4                    242
+#define __NR_recvmmsg                   243
+#define __NR_arch_specific_syscall      244
+#define __NR_wait4                      260
+#define __NR_prlimit64                  261
+#define __NR_fanotify_init              262
+#define __NR_fanotify_mark              263
+#define __NR_name_to_handle_at          264
+#define __NR_open_by_handle_at          265
+#define __NR_clock_adjtime              266
+#define __NR_syncfs                     267
+#define __NR_setns                      268
+#define __NR_sendmmsg                   269
+#define __NR_process_vm_readv           270
+#define __NR_process_vm_writev          271
+#define __NR_kcmp                       272
+#define __NR_finit_module               273
+#define __NR_sched_setattr              274
+#define __NR_sched_getattr              275
+#define __NR_renameat2                  276
+#define __NR_seccomp                    277
+#define __NR_getrandom                  278
+#define __NR_memfd_create               279
+#define __NR_bpf                        280
+#define __NR_execveat                   281
+#define __NR_userfaultfd                282
+#define __NR_membarrier                 283
+#define __NR_mlock2                     284
+#define __NR_copy_file_range            285
+#define __NR_preadv2                    286
+#define __NR_pwritev2                   287
+#define __NR_pkey_mprotect              288
+#define __NR_pkey_alloc                 289
+#define __NR_pkey_free                  290
+#define __NR_statx                      291
+#define __NR_io_pgetevents              292
+#define __NR_rseq                       293
+#define __NR_kexec_file_load            294
+#define __NR_pidfd_send_signal          424
+#define __NR_io_uring_setup             425
+#define __NR_io_uring_enter             426
+#define __NR_io_uring_register          427
+#define __NR_open_tree		        428
+#define __NR_move_mount		        429
+#define __NR_fsopen		        430
+#define __NR_fsconfig		        431
+#define __NR_fsmount		        432
+#define __NR_fspick		        433
+#define __NR_pidfd_open		        434
+#define __NR_clone3		        435
+#define __NR_close_range	        436
+#define __NR_openat2		        437
+#define __NR_pidfd_getfd	        438
+#define __NR_faccessat2		        439
+#define __NR_process_madvise	        440
+#define __NR_fcntl                      __NR3264_fcntl
+#define __NR_statfs                     __NR3264_statfs
+#define __NR_fstatfs                    __NR3264_fstatfs
+#define __NR_truncate                   __NR3264_truncate
+#define __NR_ftruncate                  __NR3264_ftruncate
+#define __NR_lseek                      __NR3264_lseek
+#define __NR_sendfile                   __NR3264_sendfile
+#define __NR_mmap                       __NR3264_mmap
+#define __NR_fadvise64                  __NR3264_fadvise64
diff --git a/arch/loongarch64/bits/user.h b/arch/loongarch64/bits/user.h
new file mode 100644
index 00000000..4d4cd534
--- /dev/null
+++ b/arch/loongarch64/bits/user.h
@@ -0,0 +1,5 @@
+#define ELF_NGREG	45
+#define ELF_NFPREG	33
+
+typedef unsigned long elf_greg_t, elf_gregset_t[ELF_NGREG];
+typedef double elf_fpreg_t, elf_fpregset_t[ELF_NFPREG];
diff --git a/arch/loongarch64/crt_arch.h b/arch/loongarch64/crt_arch.h
new file mode 100644
index 00000000..c806a0bf
--- /dev/null
+++ b/arch/loongarch64/crt_arch.h
@@ -0,0 +1,14 @@
+__asm__(
+".text \n"
+".global " START "\n"
+".type   " START ", @function\n"
+START ":\n"
+"	add.w $fp, $r0,$r0\n"
+"	or $a0, $sp, $zero\n"
+".weak _DYNAMIC\n"
+".hidden _DYNAMIC\n"
+"	la.local $a1, _DYNAMIC\n"
+"	addi.w $t7, $r0, -16\n"
+"	and $sp, $sp, $t7\n"
+"	b " START "_c\n"
+);
diff --git a/arch/loongarch64/kstat.h b/arch/loongarch64/kstat.h
new file mode 100644
index 00000000..900f119d
--- /dev/null
+++ b/arch/loongarch64/kstat.h
@@ -0,0 +1,21 @@
+struct kstat {
+	dev_t st_dev;
+	ino_t st_ino;
+	mode_t st_mode;
+	nlink_t st_nlink;
+	uid_t st_uid;
+	gid_t st_gid;
+	dev_t st_rdev;
+	unsigned long __pad;
+	off_t st_size;
+	blksize_t st_blksize;
+	int __pad2;
+	blkcnt_t st_blocks;
+	long st_atime_sec;
+	unsigned long st_atime_nsec;
+	long st_mtime_sec;
+	unsigned long st_mtime_nsec;
+	long st_ctime_sec;
+	unsigned long st_ctime_nsec;
+	unsigned __unused[2];
+};
diff --git a/arch/loongarch64/pthread_arch.h b/arch/loongarch64/pthread_arch.h
new file mode 100644
index 00000000..95ee4c7a
--- /dev/null
+++ b/arch/loongarch64/pthread_arch.h
@@ -0,0 +1,13 @@
+static inline uintptr_t __get_tp()
+{
+	register uintptr_t tp __asm__("tp");
+	__asm__ ("" : "=r" (tp) );
+	return tp;
+}
+
+#define TLS_ABOVE_TP
+#define GAP_ABOVE_TP 0
+
+#define DTP_OFFSET 0
+
+#define MC_PC pc
diff --git a/arch/loongarch64/reloc.h b/arch/loongarch64/reloc.h
new file mode 100644
index 00000000..249cb40c
--- /dev/null
+++ b/arch/loongarch64/reloc.h
@@ -0,0 +1,35 @@
+#ifndef __RELOC_H__
+#define __RELOC_H__
+
+#define _GNU_SOURCE
+#include <endian.h>
+
+#ifdef __loongarch64_soft_float
+#define FP_SUFFIX "-sf"
+#else
+#define FP_SUFFIX ""
+#endif
+
+#define LDSO_ARCH "loongarch64"  FP_SUFFIX
+
+#define TPOFF_K (0x0)
+
+#define REL_PLT         R_LARCH_JUMP_SLOT
+#define REL_COPY        R_LARCH_COPY
+#define REL_DTPMOD      R_LARCH_TLS_DTPMOD64
+#define REL_DTPOFF      R_LARCH_TLS_DTPREL64
+#define REL_TPOFF       R_LARCH_TLS_TPREL64
+#define REL_RELATIVE    R_LARCH_RELATIVE
+#define REL_SYMBOLIC    R_LARCH_64
+
+#define CRTJMP(pc,sp) __asm__ __volatile__( \
+	"move $sp,%1 ; jr %0" : : "r"(pc), "r"(sp) : "memory" )
+
+#define GETFUNCSYM(fp, sym, got) __asm__ ( \
+	".hidden " #sym "\n" \
+	".align 8 \n" \
+	"	la.local $t1, "#sym" \n" \
+	"	or %0, $t1, $zero \n" \
+	: "=r"(*(fp)) : : "memory" )
+
+#endif
diff --git a/arch/loongarch64/syscall_arch.h b/arch/loongarch64/syscall_arch.h
new file mode 100644
index 00000000..ddd29578
--- /dev/null
+++ b/arch/loongarch64/syscall_arch.h
@@ -0,0 +1,137 @@
+#define __SYSCALL_LL_E(x) (x)
+#define __SYSCALL_LL_O(x) (x)
+
+#define SYSCALL_CLOBBERLIST \
+	"$t0", "$t1", "$t2", "$t3", \
+	"$t4", "$t5", "$t6", "$t7", "$t8", "memory"
+
+static inline long __syscall0(long n)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0");
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "=r"(a0)
+		: "r"(a7)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall1(long n, long a)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+		: "r"(a7)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall2(long n, long a, long b)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+	register long a1 __asm__("$a1") = b;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+	        : "r"(a7), "r"(a1)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall3(long n, long a, long b, long c)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+	register long a1 __asm__("$a1") = b;
+	register long a2 __asm__("$a2") = c;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+	        : "r"(a7), "r"(a1), "r"(a2)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall4(long n, long a, long b, long c, long d)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+	register long a1 __asm__("$a1") = b;
+	register long a2 __asm__("$a2") = c;
+	register long a3 __asm__("$a3") = d;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+	        : "r"(a7), "r"(a1), "r"(a2), "r"(a3)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall5(long n, long a, long b, long c, long d, long e)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+	register long a1 __asm__("$a1") = b;
+	register long a2 __asm__("$a2") = c;
+	register long a3 __asm__("$a3") = d;
+	register long a4 __asm__("$a4") = e;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+	        : "r"(a7), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall6(long n, long a, long b, long c, long d, long e, long f)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+	register long a1 __asm__("$a1") = b;
+	register long a2 __asm__("$a2") = c;
+	register long a3 __asm__("$a3") = d;
+	register long a4 __asm__("$a4") = e;
+	register long a5 __asm__("$a5") = f;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+	        : "r"(a7), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+static inline long __syscall7(long n, long a, long b, long c, long d, long e, long f, long g)
+{
+	register long a7 __asm__("$a7") = n;
+	register long a0 __asm__("$a0") = a;
+	register long a1 __asm__("$a1") = b;
+	register long a2 __asm__("$a2") = c;
+	register long a3 __asm__("$a3") = d;
+	register long a4 __asm__("$a4") = e;
+	register long a5 __asm__("$a5") = f;
+	register long a6 __asm__("$a6") = g;
+
+	__asm__ __volatile__ (
+		"syscall 0"
+		: "+r"(a0)
+	        : "r"(a7), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5), "r"(a6)
+		: SYSCALL_CLOBBERLIST);
+	return a0;
+}
+
+#define VDSO_USEFUL
+#define VDSO_CGT_SYM "__vdso_clock_gettime"
+#define VDSO_CGT_VER "LINUX_2.6"
+
+#define IPC_64  0
diff --git a/configure b/configure
index 6f5453f5..aac0c467 100755
--- a/configure
+++ b/configure
@@ -338,6 +338,7 @@ powerpc*|ppc*) ARCH=powerpc ;;
 riscv64*) ARCH=riscv64 ;;
 sh[1-9bel-]*|sh|superh*) ARCH=sh ;;
 s390x*) ARCH=s390x ;;
+loongarch64*) ARCH=loongarch64 ;;
 unknown) fail "$0: unable to detect target arch; try $0 --target=..." ;;
 *) fail "$0: unknown or unsupported target \"$target\"" ;;
 esac
diff --git a/crt/loongarch64/crti.s b/crt/loongarch64/crti.s
new file mode 100644
index 00000000..96a754d3
--- /dev/null
+++ b/crt/loongarch64/crti.s
@@ -0,0 +1,15 @@
+.section .init
+.global _init
+_init:
+	addi.d	$r3,$r3,-16
+	st.d	$fp,$r3,0
+	st.d	$ra,$r3,8
+	addi.d  $fp,$r3,16
+
+.section .fini
+.global _fini
+_fini:
+	addi.d	$r3,$r3,-16
+	st.d	$fp,$r3,0
+	st.d	$ra,$r3,8
+	addi.d  $fp,$r3,16
diff --git a/crt/loongarch64/crtn.s b/crt/loongarch64/crtn.s
new file mode 100644
index 00000000..bffb18f4
--- /dev/null
+++ b/crt/loongarch64/crtn.s
@@ -0,0 +1,12 @@
+.section .init
+	ld.d	$fp,$r3,0
+	ld.d	$ra,$r3,8
+	addi.d	$r3,$r3,16
+	jirl	$r0,$ra,0
+
+
+.section .fini
+	ld.d	$fp,$r3,0
+	ld.d	$ra,$r3,8
+	addi.d	$r3,$r3,16
+	jirl	$r0,$ra,0
diff --git a/include/elf.h b/include/elf.h
index 86e2f0bb..69b01ff4 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -697,6 +697,11 @@ typedef struct {
 #define NT_MIPS_FP_MODE	0x801
 #define NT_MIPS_MSA	0x802
 #define NT_VERSION	1
+#define NT_LOONGARCH_CPUCFG	0xa00
+#define NT_LOONGARCH_CSR	0xa01
+#define NT_LOONGARCH_LSX	0xa02
+#define NT_LOONGARCH_LASX	0xa03
+#define NT_LOONGARCH_LBT	0xa04
 
 
 
@@ -3288,6 +3293,67 @@ enum
 #define R_RISCV_SET32           56
 #define R_RISCV_32_PCREL        57
 
+/* LoongISA ELF Flags */
+#define EM_LOONGARCH  258
+
+#define EF_LARCH_ABI             0x0003
+#define EF_LARCH_ABI_LP64        0x0003
+#define EF_LARCH_ABI_LP32        0x0001
+
+/* Loongarch specific dynamic relocations. */
+#define R_LARCH_NONE                        0
+#define R_LARCH_32                          1
+#define R_LARCH_64                          2
+#define R_LARCH_RELATIVE                    3
+#define R_LARCH_COPY                        4
+#define R_LARCH_JUMP_SLOT                   5
+#define R_LARCH_TLS_DTPMOD32                6
+#define R_LARCH_TLS_DTPMOD64                7
+#define R_LARCH_TLS_DTPREL32                8
+#define R_LARCH_TLS_DTPREL64                9
+#define R_LARCH_TLS_TPREL32                 10
+#define R_LARCH_TLS_TPREL64                 11
+#define R_LARCH_IRELATIVE                   12
+#define R_LARCH_MARK_LA                     20
+#define R_LARCH_MARK_PCREL                  21
+#define R_LARCH_SOP_PUSH_PCREL              22
+#define R_LARCH_SOP_PUSH_ABSOLUTE           23
+#define R_LARCH_SOP_PUSH_DUP                24
+#define R_LARCH_SOP_PUSH_GPREL              25
+#define R_LARCH_SOP_PUSH_TLS_TPREL          26
+#define R_LARCH_SOP_PUSH_TLS_GOT            27
+#define R_LARCH_SOP_PUSH_TLS_GD             28
+#define R_LARCH_SOP_PUSH_PLT_PCREL          29
+#define R_LARCH_SOP_ASSERT                  30
+#define R_LARCH_SOP_NOT                     31
+#define R_LARCH_SOP_SUB                     32
+#define R_LARCH_SOP_SL                      33
+#define R_LARCH_SOP_SR                      34
+#define R_LARCH_SOP_ADD                     35
+#define R_LARCH_SOP_AND                     36
+#define R_LARCH_SOP_IF_ELSE                 37
+#define R_LARCH_SOP_POP_32_S_10_5           38
+#define R_LARCH_SOP_POP_32_U_10_12          39
+#define R_LARCH_SOP_POP_32_S_10_12          40
+#define R_LARCH_SOP_POP_32_S_10_16          41
+#define R_LARCH_SOP_POP_32_S_10_16_S2       42
+#define R_LARCH_SOP_POP_32_S_5_20           43
+#define R_LARCH_SOP_POP_32_S_0_5_10_16_S2   44
+#define R_LARCH_SOP_POP_32_S_0_10_10_16_S2  45
+#define R_LARCH_SOP_POP_32_U                46
+#define R_LARCH_ADD8                        47
+#define R_LARCH_ADD16                       48
+#define R_LARCH_ADD24                       49
+#define R_LARCH_ADD32                       50
+#define R_LARCH_ADD64                       51
+#define R_LARCH_SUB8                        52
+#define R_LARCH_SUB16                       53
+#define R_LARCH_SUB24                       54
+#define R_LARCH_SUB32                       55
+#define R_LARCH_SUB64                       56
+#define R_LARCH_GNU_VTINHERIT               57
+#define R_LARCH_GNU_VTENTRY                 58
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/fenv/loongarch64/fenv.S b/src/fenv/loongarch64/fenv.S
new file mode 100644
index 00000000..049234be
--- /dev/null
+++ b/src/fenv/loongarch64/fenv.S
@@ -0,0 +1,72 @@
+#ifndef __loongarch_soft_float
+
+.global	feclearexcept
+.type	feclearexcept,@function
+feclearexcept:
+	li.w    $a1, 0x1f0000  //flags in 16-20 bit of fcsr0.
+	and     $a0, $a0, $a1
+	movfcsr2gr $a1, $r0
+	or	$a1, $a1, $a0
+	xor	$a1, $a1, $a0
+	movgr2fcsr $r0, $a1
+	li.w    $v0, 0
+	jirl    $zero, $ra, 0
+
+.global	feraiseexcept
+.type	feraiseexcept,@function
+feraiseexcept:
+	li.w    $a1, 0x1f0000
+	and     $a0, $a0, $a1
+	movfcsr2gr $a1, $r0
+	or	$a1, $a1, $a0
+	movgr2fcsr $r0, $a1
+        li.w    $v0, 0
+	jirl    $zero, $ra, 0
+
+.global	fetestexcept
+.type	fetestexcept,@function
+fetestexcept:
+        li.w    $a1, 0x1f0000
+        and     $a0, $a0, $a1
+	movfcsr2gr $a1, $r0
+        and     $v0, $a1, $a0
+	jirl    $zero, $ra, 0
+
+.global	fegetround
+.type	fegetround,@function
+fegetround:
+	movfcsr2gr $v0, $r0
+        andi    $v0, $v0, 0x300  //fcsr0.RM
+	jirl    $zero, $ra, 0
+
+.global	__fesetround
+.hidden __fesetround
+.type	__fesetround,@function
+__fesetround:
+	movfcsr2gr $a1, $r0
+	li.w	$a2, -769  //0xfffffcff
+	and	$a1, $a1, $a2
+	or	$a1, $a1, $a0
+	movgr2fcsr $r0, $a1
+        li.w    $v0, 0
+	jirl    $zero, $ra, 0
+
+.global	fegetenv
+.type	fegetenv,@function
+fegetenv:
+	movfcsr2gr $a1, $r0
+	st.w	$a1, $a0, 0
+        li.w    $v0, 0
+	jirl    $zero, $ra, 0
+
+.global	fesetenv
+.type	fesetenv,@function
+fesetenv:
+	addi.d	$a1, $a0, 1
+	beq	$a1, $r0, 1f
+	ld.w	$a1, $a0, 0
+1:	movgr2fcsr $r0, $a1
+        li.w    $v0, 0
+	jirl    $zero, $ra, 0
+
+#endif
diff --git a/src/ldso/loongarch64/dlsym.s b/src/ldso/loongarch64/dlsym.s
new file mode 100644
index 00000000..10ac5c7f
--- /dev/null
+++ b/src/ldso/loongarch64/dlsym.s
@@ -0,0 +1,12 @@
+.global dlsym
+.hidden __dlsym
+.type   dlsym,@function
+dlsym:
+	move	$a2, $ra
+	la.global	$r16, __dlsym
+	addi.d 	$sp, $sp, -8
+	st.d	$ra, $sp, 0
+	jirl	$ra, $r16, 0
+	ld.d	$ra, $sp, 0
+	addi.d	$sp, $sp, 8
+	jirl	$r0, $ra, 0
diff --git a/src/setjmp/loongarch64/longjmp.S b/src/setjmp/loongarch64/longjmp.S
new file mode 100644
index 00000000..41d897ed
--- /dev/null
+++ b/src/setjmp/loongarch64/longjmp.S
@@ -0,0 +1,37 @@
+.global    _longjmp
+.global    longjmp
+.type    _longjmp,@function
+.type    longjmp,@function
+_longjmp:
+longjmp:
+	add.d   $t5, $a0, $zero
+	add.d   $v0, $a1, $zero
+
+	bne     $v0, $zero, 1f
+	addi.d  $v0, $v0, 1
+
+1:
+	ld.d    $ra, $t5, 0
+	ld.d    $sp, $t5, 8
+	ld.d    $r21,$t5, 16
+	ld.d    $fp, $t5, 24
+	ld.d    $s0, $t5, 32
+	ld.d    $s1, $t5, 40
+	ld.d    $s2, $t5, 48
+	ld.d    $s3, $t5, 56
+	ld.d    $s4, $t5, 64
+	ld.d    $s5, $t5, 72
+	ld.d    $s6, $t5, 80
+	ld.d    $s7, $t5, 88
+	ld.d    $s8, $t5, 96
+#ifndef __loongarch64_soft_float
+	fld.d   $fs0, $t5, 104
+	fld.d   $fs1, $t5, 112
+	fld.d   $fs2, $t5, 120
+	fld.d   $fs3, $t5, 128
+	fld.d   $fs4, $t5, 136
+	fld.d   $fs5, $t5, 144
+	fld.d   $fs6, $t5, 152
+	fld.d   $fs7, $t5, 160
+#endif
+	jirl    $zero, $ra, 0
diff --git a/src/setjmp/loongarch64/setjmp.S b/src/setjmp/loongarch64/setjmp.S
new file mode 100644
index 00000000..8dca3cb8
--- /dev/null
+++ b/src/setjmp/loongarch64/setjmp.S
@@ -0,0 +1,34 @@
+.global    __setjmp
+.global    _setjmp
+.global    setjmp
+.type    __setjmp,@function
+.type    _setjmp,@function
+.type    setjmp,@function
+__setjmp:
+_setjmp:
+setjmp:
+	st.d    $ra, $a0, 0
+	st.d    $sp, $a0, 8
+	st.d    $r21,$a0, 16
+	st.d    $fp, $a0, 24
+	st.d    $s0, $a0, 32
+	st.d    $s1, $a0, 40
+	st.d    $s2, $a0, 48
+	st.d    $s3, $a0, 56
+	st.d    $s4, $a0, 64
+	st.d    $s5, $a0, 72
+	st.d    $s6, $a0, 80
+	st.d    $s7, $a0, 88
+	st.d    $s8, $a0, 96
+#ifndef __loongarch64_soft_float
+	fst.d   $fs0, $a0, 104
+	fst.d   $fs1, $a0, 112
+	fst.d   $fs2, $a0, 120
+	fst.d   $fs3, $a0, 128
+	fst.d   $fs4, $a0, 136
+	fst.d   $fs5, $a0, 144
+	fst.d   $fs6, $a0, 152
+	fst.d   $fs7, $a0, 160
+#endif
+	xor     $v0, $v0, $v0
+	jirl    $zero, $ra, 0
diff --git a/src/signal/loongarch64/restore.s b/src/signal/loongarch64/restore.s
new file mode 100644
index 00000000..9bf015a0
--- /dev/null
+++ b/src/signal/loongarch64/restore.s
@@ -0,0 +1,10 @@
+.global	__restore_rt
+.global	__restore
+.hidden __restore_rt
+.hidden __restore
+.type	__restore_rt,@function
+.type	__restore,@function
+__restore_rt:
+__restore:
+	ori	$a7, $zero, 139
+	syscall	0
diff --git a/src/signal/loongarch64/sigsetjmp.s b/src/signal/loongarch64/sigsetjmp.s
new file mode 100644
index 00000000..d53f334a
--- /dev/null
+++ b/src/signal/loongarch64/sigsetjmp.s
@@ -0,0 +1,29 @@
+.global sigsetjmp
+.global __sigsetjmp
+.type   sigsetjmp,@function
+.type   __sigsetjmp,@function
+sigsetjmp:
+__sigsetjmp:
+        or $t5, $a0, $zero
+        or $t6, $a1, $zero
+
+        # comparing save mask with 0, if equals to 0 then
+        # sigsetjmp is equal to setjmp.
+        beq     $t6, $zero, 1f
+        st.d    $ra, $t5, 168
+
+        # save base of got so that we can use it later
+        # once we return from 'longjmp'
+        la.global  $t8, setjmp
+        jirl    $ra, $t8, 0
+
+        or      $v1, $v0, $zero # Return from 'setjmp' or 'longjmp'
+        ld.d    $ra, $t5, 168   # Restore ra of sigsetjmp
+        or      $a0, $t5, $zero
+
+.hidden __sigsetjmp_tail
+        la.global  $t8, __sigsetjmp_tail
+        jirl       $zero, $t8, 0
+1:
+        la.global  $t8, setjmp
+        jirl       $zero, $t8, 0
diff --git a/src/thread/loongarch64/__set_thread_area.s b/src/thread/loongarch64/__set_thread_area.s
new file mode 100644
index 00000000..421cd381
--- /dev/null
+++ b/src/thread/loongarch64/__set_thread_area.s
@@ -0,0 +1,7 @@
+.global	__set_thread_area
+.hidden __set_thread_area
+.type	__set_thread_area,@function
+__set_thread_area:
+	or	$tp, $a0, $zero
+	ori	$a0, $zero, 0
+	jirl	$zero, $ra, 0
diff --git a/src/thread/loongarch64/__unmapself.s b/src/thread/loongarch64/__unmapself.s
new file mode 100644
index 00000000..b77e6d1d
--- /dev/null
+++ b/src/thread/loongarch64/__unmapself.s
@@ -0,0 +1,7 @@
+.global	__unmapself
+.type	__unmapself, @function
+__unmapself:
+	li.d	$a7, 215
+	syscall	0				# call munmap
+	li.d	$a7, 93
+	syscall	0				# call exit
diff --git a/src/thread/loongarch64/clone.s b/src/thread/loongarch64/clone.s
new file mode 100644
index 00000000..ec920c7b
--- /dev/null
+++ b/src/thread/loongarch64/clone.s
@@ -0,0 +1,47 @@
+#__clone(func, stack, flags, arg, ptid, tls, ctid)
+#         a0,    a1,   a2,    a3,  a4,  a5,   a6
+# sys_clone3(struct clone_args *cl_args, size_t size)
+#                                 a0             a1
+
+.global	__clone
+.hidden __clone
+.type	__clone,@function
+__clone:
+	# Save function pointer and argument pointer on new thread stack
+	addi.d	$a1, $a1, -16
+	st.d	$a0, $a1, 0	# save function pointer
+	st.d	$a3, $a1, 8	# save argument pointer
+
+	li.d	$t0, ~0x004000ff  # mask CSIGNAL and CLONE_DETACHED
+	and	$t1, $a2, $t0     # cl_args.flags
+	li.d	$t0, 0x000000ff   # CSIGNAL
+	and	$t2, $a2, $t0     # cl_args.exit_signal
+
+	bstrins.d $sp, $zero, 2, 0  # align stack to 8 bytes
+	addi.d	$sp, $sp, -88   # struct clone_args
+	st.d	$t1, $sp, 0     # flags
+	st.d	$a4, $sp, 8     # pidfd
+	st.d	$a6, $sp, 16    # child_tid
+	st.d	$a4, $sp, 24    # parent_tid
+	st.d	$t2, $sp, 32    # exit_signal
+	st.d	$a1, $sp, 40    # stack
+	st.d	$zero, $sp, 48  # stack_size
+	st.d	$a5, $sp, 56    # tls
+	st.d	$zero, $sp, 64  # set_tid
+	st.d	$zero, $sp, 72  # set_tid_size
+	st.d	$zero, $sp, 80  # cgroup
+
+	move	$a0, $sp
+	li.d	$a1, 88
+	li.d	$a7, 435	# __NR_clone3
+	syscall 0		# call clone3
+
+	beqz	$a0, 1f		# whether child process
+	addi.d	$sp, $sp, 88
+	jirl	$zero, $ra, 0	# parent process return
+1:
+	ld.d	$t8, $sp, 0     # function pointer
+	ld.d	$a0, $sp, 8     # argument pointer
+	jirl	$ra, $t8, 0     # call the user's function
+	li.d	$a7, 93
+	syscall	0		# child process exit
diff --git a/src/thread/loongarch64/syscall_cp.s b/src/thread/loongarch64/syscall_cp.s
new file mode 100644
index 00000000..3903ed2c
--- /dev/null
+++ b/src/thread/loongarch64/syscall_cp.s
@@ -0,0 +1,29 @@
+.global	__cp_begin
+.hidden	__cp_begin
+.global	__cp_end
+.hidden	__cp_end
+.global	__cp_cancel
+.hidden	__cp_cancel
+.hidden	__cancel
+.global	__syscall_cp_asm
+.hidden	__syscall_cp_asm
+.type	__syscall_cp_asm,@function
+
+__syscall_cp_asm:
+__cp_begin:
+	ld.w	$a0, $a0, 0
+	bnez	$a0, __cp_cancel
+	or	$t8, $a1, $zero     # reserve system call number
+	or	$a0, $a2, $zero
+	or	$a1, $a3, $zero
+	or	$a2, $a4, $zero
+	or	$a3, $a5, $zero
+	or	$a4, $a6, $zero
+	or	$a5, $a7, $zero
+	or	$a7, $t8, $zero
+	syscall	0
+__cp_end:
+	jirl	$zero, $ra, 0
+__cp_cancel:
+	la.local $t8, __cancel
+	jirl	$zero, $t8, 0
-- 
2.34.1


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [musl] Re: add loongarch64 port v3
  2022-05-05  3:21 [musl] add loongarch64 port v3 王洪亮
@ 2022-05-09  1:34 ` 王洪亮
  2022-05-11 13:37   ` Rich Felker
  2022-05-16 14:27 ` [musl] " Rich Felker
  1 sibling, 1 reply; 13+ messages in thread
From: 王洪亮 @ 2022-05-09  1:34 UTC (permalink / raw)
  To: musl


在 2022/5/5 上午11:21, 王洪亮 写道:
> Hi,
>
> I published loongarch64 port v3 in
> https://github.com/loongson/musl/tree/loongarch-v2.0.
>
> fixed two problem:
>
> 1.use __NR_clone3 in  __clone().
>
> 2.remove __NR_fstat and __NR_newfstatat.
>
> please code review if there are any other problems ? thanks.
>
>
> Hongliang Wang.
>
Hi,

this port has any other problems need to fix?


Hongliang Wang.



^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] Re: add loongarch64 port v3
  2022-05-09  1:34 ` [musl] " 王洪亮
@ 2022-05-11 13:37   ` Rich Felker
  2022-05-11 16:08     ` Arnd Bergmann
  0 siblings, 1 reply; 13+ messages in thread
From: Rich Felker @ 2022-05-11 13:37 UTC (permalink / raw)
  To: musl

On Mon, May 09, 2022 at 09:34:59AM +0800, 王洪亮 wrote:
> 
> 在 2022/5/5 上午11:21, 王洪亮 写道:
> >Hi,
> >
> >I published loongarch64 port v3 in
> >https://github.com/loongson/musl/tree/loongarch-v2.0.
> >
> >fixed two problem:
> >
> >1.use __NR_clone3 in  __clone().
> >
> >2.remove __NR_fstat and __NR_newfstatat.
> >
> >please code review if there are any other problems ? thanks.
> >
> >
> >Hongliang Wang.
> >
> Hi,
> 
> this port has any other problems need to fix?

I'm at least waiting for confirmation from the kernel side that
everything is okay with syscall usage to move forward. I'll try to
look over the rest again soon to check that there are no remaining
issues.

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] Re: add loongarch64 port v3
  2022-05-11 13:37   ` Rich Felker
@ 2022-05-11 16:08     ` Arnd Bergmann
  0 siblings, 0 replies; 13+ messages in thread
From: Arnd Bergmann @ 2022-05-11 16:08 UTC (permalink / raw)
  To: musl

On Wed, May 11, 2022 at 5:57 PM Rich Felker <dalias@libc.org> wrote:
>
> On Mon, May 09, 2022 at 09:34:59AM +0800, 王洪亮 wrote:
> >
> > 在 2022/5/5 上午11:21, 王洪亮 写道:
> > >Hi,
> > >
> > >I published loongarch64 port v3 in
> > >https://github.com/loongson/musl/tree/loongarch-v2.0.
> > >
> > >fixed two problem:
> > >
> > >1.use __NR_clone3 in  __clone().
> > >
> > >2.remove __NR_fstat and __NR_newfstatat.
> > >
> > >please code review if there are any other problems ? thanks.
> > >
> > >
> > >Hongliang Wang.
> > >
> > Hi,
> >
> > this port has any other problems need to fix?
>
> I'm at least waiting for confirmation from the kernel side that
> everything is okay with syscall usage to move forward. I'll try to
> look over the rest again soon to check that there are no remaining
> issues.

Since musl is using clone3 internally and no longer exports the
__NR_fstat/newfstatat macros, that part is fine. The clone()
one still isn't correct I think, as the mainline kernel does not yet
support the emulation with a zero-length stack length. Once
we add that part, musl should be fine, but then the __NR_clone
definition is mismatched, as the kernel won't provide that call
to user applications any more.

      Arnd

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-05  3:21 [musl] add loongarch64 port v3 王洪亮
  2022-05-09  1:34 ` [musl] " 王洪亮
@ 2022-05-16 14:27 ` Rich Felker
  2022-05-21  6:38   ` 王洪亮
  1 sibling, 1 reply; 13+ messages in thread
From: Rich Felker @ 2022-05-16 14:27 UTC (permalink / raw)
  To: 王洪亮; +Cc: musl

On Thu, May 05, 2022 at 11:21:01AM +0800, 王洪亮 wrote:
> Hi,
> 
> I published loongarch64 port v3 in
> https://github.com/loongson/musl/tree/loongarch-v2.0.
> 
> fixed two problem:
> 
> 1.use __NR_clone3 in  __clone().
> 
> 2.remove __NR_fstat and __NR_newfstatat.
> 
> please code review if there are any other problems ? thanks.
> 
> 
> Hongliang Wang.

OK, review follows:

> diff --git a/arch/loongarch64/bits/signal.h b/arch/loongarch64/bits/signal.h
> new file mode 100644
> index 00000000..e6613516
> --- /dev/null
> +++ b/arch/loongarch64/bits/signal.h
> @@ -0,0 +1,79 @@
> +#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
> + || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
> +
> +#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
> +#define MINSIGSTKSZ 4096
> +#define SIGSTKSZ 16384
> +#endif
> +
> +typedef unsigned long greg_t, gregset_t[32];
> +
> +typedef struct sigcontext {
> +	unsigned long pc;
> +	gregset_t gregs;
> +	unsigned int flags;
> +	unsigned long extcontext[0] __attribute__((__aligned__(16)));
> +}mcontext_t;

Again, [0] is not valid C. If the extension field is going to be
declared at all it needs to be declared in a way it can be accessed
without invoking UB, e.g. as a FAM. I'm also not clear on how
specifying the alignment here helps since any object created in a way
that the alignment would affect cannot have the FAM present.

Style nit: missing space between } and mcontext_t.

> diff --git a/arch/loongarch64/bits/stat.h b/arch/loongarch64/bits/stat.h
> new file mode 100644
> index 00000000..b7f4221b
> --- /dev/null
> +++ b/arch/loongarch64/bits/stat.h
> @@ -0,0 +1,18 @@
> +struct stat {
> +	dev_t st_dev;
> +	ino_t st_ino;
> +	mode_t st_mode;
> +	nlink_t st_nlink;
> +	uid_t st_uid;
> +	gid_t st_gid;
> +	dev_t st_rdev;
> +	unsigned long __pad;
> +	off_t st_size;
> +	blksize_t st_blksize;
> +	int __pad2;
> +	blkcnt_t st_blocks;
> +	struct timespec st_atim;
> +	struct timespec st_mtim;
> +	struct timespec st_ctim;
> +	unsigned __unused[2];
> +};

Looks like this matches the 'generic' definition now, which is good.
We haven't yet put a generic vesion in arch/generic/bits/stat.h, but
at some point that should happen and if/when it does this file can be
dropped. It's fine for now though.

> diff --git a/arch/loongarch64/kstat.h b/arch/loongarch64/kstat.h
> new file mode 100644
> index 00000000..900f119d
> --- /dev/null
> +++ b/arch/loongarch64/kstat.h
> @@ -0,0 +1,21 @@
> +struct kstat {
> +	dev_t st_dev;
> +	ino_t st_ino;
> +	mode_t st_mode;
> +	nlink_t st_nlink;
> +	uid_t st_uid;
> +	gid_t st_gid;
> +	dev_t st_rdev;
> +	unsigned long __pad;
> +	off_t st_size;
> +	blksize_t st_blksize;
> +	int __pad2;
> +	blkcnt_t st_blocks;
> +	long st_atime_sec;
> +	unsigned long st_atime_nsec;
> +	long st_mtime_sec;
> +	unsigned long st_mtime_nsec;
> +	long st_ctime_sec;
> +	unsigned long st_ctime_nsec;
> +	unsigned __unused[2];
> +};

I think this file should be removed, right? -- since there is no
legacy stat sycall with a kstat structure.

> diff --git a/arch/loongarch64/reloc.h b/arch/loongarch64/reloc.h
> new file mode 100644
> index 00000000..249cb40c
> --- /dev/null
> +++ b/arch/loongarch64/reloc.h
> @@ -0,0 +1,35 @@
> +#ifndef __RELOC_H__
> +#define __RELOC_H__
> +
> +#define _GNU_SOURCE
> +#include <endian.h>

You cannot define FTMs in the middle of a header file that might be
included somewhere other than the very top of a source file. But there
does not seem to be any reason it's defined at all.

> diff --git a/src/ldso/loongarch64/dlsym.s b/src/ldso/loongarch64/dlsym.s
> new file mode 100644
> index 00000000..10ac5c7f
> --- /dev/null
> +++ b/src/ldso/loongarch64/dlsym.s
> @@ -0,0 +1,12 @@
> +.global dlsym
> +.hidden __dlsym
> +.type   dlsym,@function
> +dlsym:
> +	move	$a2, $ra
> +	la.global	$r16, __dlsym
> +	addi.d 	$sp, $sp, -8
> +	st.d	$ra, $sp, 0
> +	jirl	$ra, $r16, 0
> +	ld.d	$ra, $sp, 0
> +	addi.d	$sp, $sp, 8
> +	jirl	$r0, $ra, 0

Is there a reason this can't be a tail call? Maybe the ABI requires
that the caller reserve space for the callee to spill arg registers
that are used?

> diff --git a/src/thread/loongarch64/clone.s b/src/thread/loongarch64/clone.s
> new file mode 100644
> index 00000000..ec920c7b
> --- /dev/null
> +++ b/src/thread/loongarch64/clone.s
> @@ -0,0 +1,47 @@
> +#__clone(func, stack, flags, arg, ptid, tls, ctid)
> +#         a0,    a1,   a2,    a3,  a4,  a5,   a6
> +# sys_clone3(struct clone_args *cl_args, size_t size)
> +#                                 a0             a1
> +
> +.global	__clone
> +.hidden __clone
> +.type	__clone,@function
> +__clone:
> +	# Save function pointer and argument pointer on new thread stack
> +	addi.d	$a1, $a1, -16
> +	st.d	$a0, $a1, 0	# save function pointer
> +	st.d	$a3, $a1, 8	# save argument pointer
> +
> +	li.d	$t0, ~0x004000ff  # mask CSIGNAL and CLONE_DETACHED
> +	and	$t1, $a2, $t0     # cl_args.flags
> +	li.d	$t0, 0x000000ff   # CSIGNAL
> +	and	$t2, $a2, $t0     # cl_args.exit_signal
> +
> +	bstrins.d $sp, $zero, 2, 0  # align stack to 8 bytes
> +	addi.d	$sp, $sp, -88   # struct clone_args
> +	st.d	$t1, $sp, 0     # flags
> +	st.d	$a4, $sp, 8     # pidfd
> +	st.d	$a6, $sp, 16    # child_tid
> +	st.d	$a4, $sp, 24    # parent_tid
> +	st.d	$t2, $sp, 32    # exit_signal
> +	st.d	$a1, $sp, 40    # stack
> +	st.d	$zero, $sp, 48  # stack_size
> +	st.d	$a5, $sp, 56    # tls
> +	st.d	$zero, $sp, 64  # set_tid
> +	st.d	$zero, $sp, 72  # set_tid_size
> +	st.d	$zero, $sp, 80  # cgroup
> +
> +	move	$a0, $sp
> +	li.d	$a1, 88
> +	li.d	$a7, 435	# __NR_clone3
> +	syscall 0		# call clone3
> +
> +	beqz	$a0, 1f		# whether child process
> +	addi.d	$sp, $sp, 88
> +	jirl	$zero, $ra, 0	# parent process return
> +1:
> +	ld.d	$t8, $sp, 0     # function pointer
> +	ld.d	$a0, $sp, 8     # argument pointer
> +	jirl	$ra, $t8, 0     # call the user's function
> +	li.d	$a7, 93
> +	syscall	0		# child process exit

Based on the outcome of the kernel discussiong about __NR_clone3 vs
__NR_clone, this likely needs to be reverted to use __NR_clone again.
I'm waiting to see how that comes out. Sorry for the back and forth
while we try to get this right on the kernel side.

If anyone else wants to take a further look at this, the things I have
not reviewed in detail are the arch-specific asm, particularly atomics
and fenv stuff that require knowledge of how the arch works. As best I
can tell these don't affect ABI and are fixable after merge if
something doesn't work right, so I'm not too concerned about them.

Rich

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-16 14:27 ` [musl] " Rich Felker
@ 2022-05-21  6:38   ` 王洪亮
  2022-05-21  8:22     ` Markus Wichmann
  0 siblings, 1 reply; 13+ messages in thread
From: 王洪亮 @ 2022-05-21  6:38 UTC (permalink / raw)
  To: musl

[-- Attachment #1: Type: text/plain, Size: 6420 bytes --]


在 2022/5/16 下午10:27, Rich Felker 写道:
> OK, review follows:
>> diff --git a/arch/loongarch64/bits/signal.h b/arch/loongarch64/bits/signal.h
>> new file mode 100644
>> index 00000000..e6613516
>> --- /dev/null
>> +++ b/arch/loongarch64/bits/signal.h
>> @@ -0,0 +1,79 @@
>> +#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
>> + || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
>> +
>> +#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
>> +#define MINSIGSTKSZ 4096
>> +#define SIGSTKSZ 16384
>> +#endif
>> +
>> +typedef unsigned long greg_t, gregset_t[32];
>> +
>> +typedef struct sigcontext {
>> +	unsigned long pc;
>> +	gregset_t gregs;
>> +	unsigned int flags;
>> +	unsigned long extcontext[0] __attribute__((__aligned__(16)));
>> +}mcontext_t;
> Again, [0] is not valid C. If the extension field is going to be
> declared at all it needs to be declared in a way it can be accessed
> without invoking UB, e.g. as a FAM.

[0] is allowed in GNU C, we can not use it in musl ?

I don't understand  UB ?  e.g. as a FAM ?

> I'm also not clear on how
> specifying the alignment here helps since any object created in a way
> that the alignment would affect cannot have the FAM present.
>
the __aligned__(16)  here used to save 128bit vector later.
>
>> diff --git a/arch/loongarch64/kstat.h b/arch/loongarch64/kstat.h
>> new file mode 100644
>> index 00000000..900f119d
>> --- /dev/null
>> +++ b/arch/loongarch64/kstat.h
>> @@ -0,0 +1,21 @@
>> +struct kstat {
>> +	dev_t st_dev;
>> +	ino_t st_ino;
>> +	mode_t st_mode;
>> +	nlink_t st_nlink;
>> +	uid_t st_uid;
>> +	gid_t st_gid;
>> +	dev_t st_rdev;
>> +	unsigned long __pad;
>> +	off_t st_size;
>> +	blksize_t st_blksize;
>> +	int __pad2;
>> +	blkcnt_t st_blocks;
>> +	long st_atime_sec;
>> +	unsigned long st_atime_nsec;
>> +	long st_mtime_sec;
>> +	unsigned long st_mtime_nsec;
>> +	long st_ctime_sec;
>> +	unsigned long st_ctime_nsec;
>> +	unsigned __unused[2];
>> +};
> I think this file should be removed, right? -- since there is no
> legacy stat sycall with a kstat structure.
yes, I removed this file.
>> diff --git a/arch/loongarch64/reloc.h b/arch/loongarch64/reloc.h
>> new file mode 100644
>> index 00000000..249cb40c
>> --- /dev/null
>> +++ b/arch/loongarch64/reloc.h
>> @@ -0,0 +1,35 @@
>> +#ifndef __RELOC_H__
>> +#define __RELOC_H__
>> +
>> +#define _GNU_SOURCE
>> +#include <endian.h>
> You cannot define FTMs in the middle of a header file that might be
> included somewhere other than the very top of a source file. But there
> does not seem to be any reason it's defined at all.

I fixed this error:

diff --git a/arch/loongarch64/reloc.h b/arch/loongarch64/reloc.h

index 249cb40c..2f759a34 100644
--- a/arch/loongarch64/reloc.h
+++ b/arch/loongarch64/reloc.h
@@ -1,9 +1,3 @@
-#ifndef __RELOC_H__
-#define __RELOC_H__
-
-#define _GNU_SOURCE
-#include <endian.h>
-
  #ifdef __loongarch64_soft_float
  #define FP_SUFFIX "-sf"
  #else
@@ -31,5 +25,3 @@
      "    la.local $t1, "#sym" \n" \
      "    or %0, $t1, $zero \n" \
      : "=r"(*(fp)) : : "memory" )
-
-#endif

>> diff --git a/src/ldso/loongarch64/dlsym.s b/src/ldso/loongarch64/dlsym.s
>> new file mode 100644
>> index 00000000..10ac5c7f
>> --- /dev/null
>> +++ b/src/ldso/loongarch64/dlsym.s
>> @@ -0,0 +1,12 @@
>> +.global dlsym
>> +.hidden __dlsym
>> +.type   dlsym,@function
>> +dlsym:
>> +	move	$a2, $ra
>> +	la.global	$r16, __dlsym
>> +	addi.d 	$sp, $sp, -8
>> +	st.d	$ra, $sp, 0
>> +	jirl	$ra, $r16, 0
>> +	ld.d	$ra, $sp, 0
>> +	addi.d	$sp, $sp, 8
>> +	jirl	$r0, $ra, 0
> Is there a reason this can't be a tail call? Maybe the ABI requires
> that the caller reserve space for the callee to spill arg registers
> that are used?

I optimized the code implementation:

diff --git a/src/ldso/loongarch64/dlsym.s b/src/ldso/loongarch64/dlsym.s
index 10ac5c7f..5f51ed85 100644
--- a/src/ldso/loongarch64/dlsym.s
+++ b/src/ldso/loongarch64/dlsym.s
@@ -4,9 +4,4 @@
  dlsym:
      move    $a2, $ra
      la.global    $r16, __dlsym
-    addi.d     $sp, $sp, -8
-    st.d    $ra, $sp, 0
-    jirl    $ra, $r16, 0
-    ld.d    $ra, $sp, 0
-    addi.d    $sp, $sp, 8
-    jirl    $r0, $ra, 0
+    jirl    $r0, $r16, 0
-- 

>> diff --git a/src/thread/loongarch64/clone.s b/src/thread/loongarch64/clone.s
>> new file mode 100644
>> index 00000000..ec920c7b
>> --- /dev/null
>> +++ b/src/thread/loongarch64/clone.s
>> @@ -0,0 +1,47 @@
>> +#__clone(func, stack, flags, arg, ptid, tls, ctid)
>> +#         a0,    a1,   a2,    a3,  a4,  a5,   a6
>> +# sys_clone3(struct clone_args *cl_args, size_t size)
>> +#                                 a0             a1
>> +
>> +.global	__clone
>> +.hidden __clone
>> +.type	__clone,@function
>> +__clone:
>> +	# Save function pointer and argument pointer on new thread stack
>> +	addi.d	$a1, $a1, -16
>> +	st.d	$a0, $a1, 0	# save function pointer
>> +	st.d	$a3, $a1, 8	# save argument pointer
>> +
>> +	li.d	$t0, ~0x004000ff  # mask CSIGNAL and CLONE_DETACHED
>> +	and	$t1, $a2, $t0     # cl_args.flags
>> +	li.d	$t0, 0x000000ff   # CSIGNAL
>> +	and	$t2, $a2, $t0     # cl_args.exit_signal
>> +
>> +	bstrins.d $sp, $zero, 2, 0  # align stack to 8 bytes
>> +	addi.d	$sp, $sp, -88   # struct clone_args
>> +	st.d	$t1, $sp, 0     # flags
>> +	st.d	$a4, $sp, 8     # pidfd
>> +	st.d	$a6, $sp, 16    # child_tid
>> +	st.d	$a4, $sp, 24    # parent_tid
>> +	st.d	$t2, $sp, 32    # exit_signal
>> +	st.d	$a1, $sp, 40    # stack
>> +	st.d	$zero, $sp, 48  # stack_size
>> +	st.d	$a5, $sp, 56    # tls
>> +	st.d	$zero, $sp, 64  # set_tid
>> +	st.d	$zero, $sp, 72  # set_tid_size
>> +	st.d	$zero, $sp, 80  # cgroup
>> +
>> +	move	$a0, $sp
>> +	li.d	$a1, 88
>> +	li.d	$a7, 435	# __NR_clone3
>> +	syscall 0		# call clone3
>> +
>> +	beqz	$a0, 1f		# whether child process
>> +	addi.d	$sp, $sp, 88
>> +	jirl	$zero, $ra, 0	# parent process return
>> +1:
>> +	ld.d	$t8, $sp, 0     # function pointer
>> +	ld.d	$a0, $sp, 8     # argument pointer
>> +	jirl	$ra, $t8, 0     # call the user's function
>> +	li.d	$a7, 93
>> +	syscall	0		# child process exit
> Based on the outcome of the kernel discussiong about __NR_clone3 vs
> __NR_clone, this likely needs to be reverted to use __NR_clone again.
> I'm waiting to see how that comes out. Sorry for the back and forth
> while we try to get this right on the kernel side.
OK,No problem.

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^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-21  6:38   ` 王洪亮
@ 2022-05-21  8:22     ` Markus Wichmann
  2022-05-24  9:08       ` 王洪亮
  0 siblings, 1 reply; 13+ messages in thread
From: Markus Wichmann @ 2022-05-21  8:22 UTC (permalink / raw)
  To: musl

On Sat, May 21, 2022 at 02:38:20PM +0800, 王洪亮 wrote:
>
> 在 2022/5/16 下午10:27, Rich Felker 写道:
> > Again, [0] is not valid C. If the extension field is going to be
> > declared at all it needs to be declared in a way it can be accessed
> > without invoking UB, e.g. as a FAM.
>
> [0] is allowed in GNU C, we can not use it in musl ?
>
> I don't understand  UB ?  e.g. as a FAM ?
>

musl tries to stay within ISO C as much as possible, and not use GNU C
extensions if it possibly can. In this case, zero-sized arrays do the
same thing as flexible array members, so there is absolutely no reason
to use the extension over the standard way.

UB = undefined behavior
FAM = flexible array member. If the last member of a structure is an
array, it can have indeterminate size. It will then not count towards
the size of the structure (only towards its alignment, possibly), and
can be indexed arbitrarily. This is a C99 feature.

So basically, just nix the 0 in that line.

> > I'm also not clear on how
> > specifying the alignment here helps since any object created in a way
> > that the alignment would affect cannot have the FAM present.
> >
> the __aligned__(16)  here used to save 128bit vector later.

But it has no effect, right? The array member is offset an integer
multiple of sixteen bytes from the start of the structure, so it is
already aligned with respect to that, and the declaration adds no
further padding (and if it did, common style in both Linux and musl is
to explicate the padding). And the pointer to the structure comes from
the kernel.

The only thing this alignment directive does is raise the alignment
requirement of the structure up to sixteen, but that only possibly
matters for variables of the structure type, be they automatic or
program life time. But from here it is hard to see why the alignment
should matter in either of those cases, since those would only possibly
be local buffers of the kernel-provided mcontext. And the kernel
provides the mcontext already with all the alignment it needs. I am not
aware of any kernel API that receives a user provided mcontext. And even
if there was one, the kernel would have to copy it into kernel space
before doing anything with it, anyway.

And, BTW, if the alignment really is needed on the mcontext_t itself, it
might be better to put the alignment tag on the type, not one of the
members.

Ciao,
Markus

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-21  8:22     ` Markus Wichmann
@ 2022-05-24  9:08       ` 王洪亮
  2022-05-24 12:32         ` Rich Felker
  0 siblings, 1 reply; 13+ messages in thread
From: 王洪亮 @ 2022-05-24  9:08 UTC (permalink / raw)
  To: musl

[-- Attachment #1: Type: text/plain, Size: 2571 bytes --]


在 2022/5/21 下午4:22, Markus Wichmann 写道:
>>> I'm also not clear on how
>>> specifying the alignment here helps since any object created in a way
>>> that the alignment would affect cannot have the FAM present.
>>>
>> the __aligned__(16)  here used to save 128bit vector later.
> But it has no effect, right? The array member is offset an integer
> multiple of sixteen bytes from the start of the structure, so it is
> already aligned with respect to that, and the declaration adds no
> further padding (and if it did, common style in both Linux and musl is
> to explicate the padding). And the pointer to the structure comes from
> the kernel.

if no __aligned__(16),the struct sigcontext is 8 bytes align,even if the 
extcontext[]

is offset an integer multiple of 16 bytes from the start of struct 
sigcontext,it can only

ensure the extcontext[] is 8 bytes align. (just only when sigcontext is 
16 bytes align,

extcontext[] can meet 16 bytes align.)


> The only thing this alignment directive does is raise the alignment
> requirement of the structure up to sixteen, but that only possibly
> matters for variables of the structure type, be they automatic or
> program life time. But from here it is hard to see why the alignment
> should matter in either of those cases, since those would only possibly
> be local buffers of the kernel-provided mcontext. And the kernel
> provides the mcontext already with all the alignment it needs. I am not
> aware of any kernel API that receives a user provided mcontext. And even
> if there was one, the kernel would have to copy it into kernel space
> before doing anything with it, anyway.

this not need kernel API, in kernel, if task has pending signal, kernel 
save context

to ucontext(in user stack space), then return to userspace to signal 
handle, from

the third parameter of signal_handler, user can access the ucontext and 
mcontext.

libc and kernel access the same ucontext in user stack space.

void signal_handler (int sig, siginfo_t *info, void *ctx) {

         ucontext_t *uc = ctx;

mcontext_t *mc = ctx->uc_mcontext;

}

> And, BTW, if the alignment really is needed on the mcontext_t itself, it
> might be better to put the alignment tag on the type, not one of the
> members.

we need extcontext[] 16 bytes align for 128bit vector access, if put the
alignment on mcontext_t itself,although it can also meet the 16 bytes align
requirements of extcontext[] (the offset is an integer multiple of 16 bytes
from the start of struct sigcontext),the meaning is not clear.

>
> Ciao,
> Markus

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^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-24  9:08       ` 王洪亮
@ 2022-05-24 12:32         ` Rich Felker
  2022-05-25 10:08           ` 王洪亮
  0 siblings, 1 reply; 13+ messages in thread
From: Rich Felker @ 2022-05-24 12:32 UTC (permalink / raw)
  To: 王洪亮; +Cc: musl

On Tue, May 24, 2022 at 05:08:21PM +0800, 王洪亮 wrote:
> 
> 在 2022/5/21 下午4:22, Markus Wichmann 写道:
> >>>I'm also not clear on how
> >>>specifying the alignment here helps since any object created in a way
> >>>that the alignment would affect cannot have the FAM present.
> >>>
> >>the __aligned__(16)  here used to save 128bit vector later.
> >But it has no effect, right? The array member is offset an integer
> >multiple of sixteen bytes from the start of the structure, so it is
> >already aligned with respect to that, and the declaration adds no
> >further padding (and if it did, common style in both Linux and musl is
> >to explicate the padding). And the pointer to the structure comes from
> >the kernel.
> 
> if no __aligned__(16),the struct sigcontext is 8 bytes align,even if
> the extcontext[]

What we've been trying to say is that there are several cases, none of
which seem to need it:

1. You create an object with declared type struct sigcontext. In this
   case, the flexible array member at the end is not present at all
   (because that's how C works) which means there's no extended
   context which needs additional alignment and probably also means
   this is not a usable way of creating sigcontext structs.

2. You malloc storage for the object with space for the flexible array
   member. In this case the allocation has alignment max_align_t and
   everything is fine.

3. You get the object from the kernel pushing it onto the stack in a
   signal frame. This is probably actually the only case the type is
   usable in, and of course it has whatever alignment the kernel gave
   it.

Rich

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-24 12:32         ` Rich Felker
@ 2022-05-25 10:08           ` 王洪亮
  2022-05-25 12:32             ` Rich Felker
  0 siblings, 1 reply; 13+ messages in thread
From: 王洪亮 @ 2022-05-25 10:08 UTC (permalink / raw)
  To: musl


在 2022/5/24 下午8:32, Rich Felker 写道:
> What we've been trying to say is that there are several cases, none of
> which seem to need it:
>
> 1. You create an object with declared type struct sigcontext. In this
>     case, the flexible array member at the end is not present at all
>     (because that's how C works) which means there's no extended
>     context which needs additional alignment and probably also means
>     this is not a usable way of creating sigcontext structs.
>
> 2. You malloc storage for the object with space for the flexible array
>     member. In this case the allocation has alignment max_align_t and
>     everything is fine.
>
> 3. You get the object from the kernel pushing it onto the stack in a
>     signal frame. This is probably actually the only case the type is
>     usable in, and of course it has whatever alignment the kernel gave
>     it.
Specify the __attribute__((__aligned__(16))) in musl,is used to be
consistent with kernel.if I removed the __attribute__((__aligned__(16))),
there is a libc-test fail in pthread_cancel.exe.the reason is that the
offset of uc->uc_mcontext from the start of uc obtained in cancel_handler
is inconsistent with kernel pushing it onto the stack in a signal frame.
so I understand the __attribute__((__aligned__(16))) is necessary in musl.

src/thread/pthread_cancel.c

static void cancel_handler(int sig, siginfo_t *si, void *ctx)
{
         pthread_t self = __pthread_self();
         ucontext_t *uc = ctx;
         uintptr_t pc = uc->uc_mcontext.MC_PC;
          ...
}

musl/arch/loongarch64/bits/signal.h:

typedef unsigned long greg_t, gregset_t[32];
typedef struct sigcontext {
         unsigned long pc;
         gregset_t gregs;
         unsigned int flags;
         unsigned long extcontext[];
}mcontext_t;

linux/arch/loongarch/include/uapi/asm/sigcontext.h:

struct sigcontext {
         __u64   sc_pc;
         __u64   sc_regs[32];
         __u32   sc_flags;
         __u64   sc_extcontext[0] __attribute__((__aligned__(16)));
};
>
> Rich


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-25 10:08           ` 王洪亮
@ 2022-05-25 12:32             ` Rich Felker
  2022-05-26  3:07               ` 王洪亮
  0 siblings, 1 reply; 13+ messages in thread
From: Rich Felker @ 2022-05-25 12:32 UTC (permalink / raw)
  To: 王洪亮; +Cc: musl

On Wed, May 25, 2022 at 06:08:23PM +0800, 王洪亮 wrote:
> 
> 在 2022/5/24 下午8:32, Rich Felker 写道:
> >What we've been trying to say is that there are several cases, none of
> >which seem to need it:
> >
> >1. You create an object with declared type struct sigcontext. In this
> >    case, the flexible array member at the end is not present at all
> >    (because that's how C works) which means there's no extended
> >    context which needs additional alignment and probably also means
> >    this is not a usable way of creating sigcontext structs.
> >
> >2. You malloc storage for the object with space for the flexible array
> >    member. In this case the allocation has alignment max_align_t and
> >    everything is fine.
> >
> >3. You get the object from the kernel pushing it onto the stack in a
> >    signal frame. This is probably actually the only case the type is
> >    usable in, and of course it has whatever alignment the kernel gave
> >    it.
> Specify the __attribute__((__aligned__(16))) in musl,is used to be
> consistent with kernel.if I removed the __attribute__((__aligned__(16))),
> there is a libc-test fail in pthread_cancel.exe.the reason is that the
> offset of uc->uc_mcontext from the start of uc obtained in cancel_handler
> is inconsistent with kernel pushing it onto the stack in a signal frame.
> so I understand the __attribute__((__aligned__(16))) is necessary in musl.
> 
> src/thread/pthread_cancel.c
> 
> static void cancel_handler(int sig, siginfo_t *si, void *ctx)
> {
>         pthread_t self = __pthread_self();
>         ucontext_t *uc = ctx;
>         uintptr_t pc = uc->uc_mcontext.MC_PC;
>          ...
> }
> 
> musl/arch/loongarch64/bits/signal.h:
> 
> typedef unsigned long greg_t, gregset_t[32];
> typedef struct sigcontext {
>         unsigned long pc;
>         gregset_t gregs;
>         unsigned int flags;
>         unsigned long extcontext[];
> }mcontext_t;
> 
> linux/arch/loongarch/include/uapi/asm/sigcontext.h:
> 
> struct sigcontext {
>         __u64   sc_pc;
>         __u64   sc_regs[32];
>         __u32   sc_flags;
>         __u64   sc_extcontext[0] __attribute__((__aligned__(16)));
> };

This is because ucontext_t is defined without explicit padding before
uc_mcontext. Add "long __uc_pad;" or similar before it so that the
offset is explicitly what it's supposed to be rather than a
consequence ot overalignment.

Rich

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-25 12:32             ` Rich Felker
@ 2022-05-26  3:07               ` 王洪亮
  2022-05-29  6:34                 ` Szabolcs Nagy
  0 siblings, 1 reply; 13+ messages in thread
From: 王洪亮 @ 2022-05-26  3:07 UTC (permalink / raw)
  To: musl


在 2022/5/25 下午8:32, Rich Felker 写道:
> On Wed, May 25, 2022 at 06:08:23PM +0800, 王洪亮 wrote:
>> 在 2022/5/24 下午8:32, Rich Felker 写道:
>>> What we've been trying to say is that there are several cases, none of
>>> which seem to need it:
>>>
>>> 1. You create an object with declared type struct sigcontext. In this
>>>     case, the flexible array member at the end is not present at all
>>>     (because that's how C works) which means there's no extended
>>>     context which needs additional alignment and probably also means
>>>     this is not a usable way of creating sigcontext structs.
>>>
>>> 2. You malloc storage for the object with space for the flexible array
>>>     member. In this case the allocation has alignment max_align_t and
>>>     everything is fine.
I don't understand what is alignment max_align_t? I found the max_align_t
definition in musl,is this it?

TYPEDEF struct { long long __ll; long double __ld; } max_align_t;

I understand if FAM is not specified alignment,FAM is aligned according to
its type size,why is max_align_t?
>>>
>>> 3. You get the object from the kernel pushing it onto the stack in a
>>>     signal frame. This is probably actually the only case the type is
>>>     usable in, and of course it has whatever alignment the kernel gave
>>>     it.
>> Specify the __attribute__((__aligned__(16))) in musl,is used to be
>> consistent with kernel.if I removed the __attribute__((__aligned__(16))),
>> there is a libc-test fail in pthread_cancel.exe.the reason is that the
>> offset of uc->uc_mcontext from the start of uc obtained in cancel_handler
>> is inconsistent with kernel pushing it onto the stack in a signal frame.
>> so I understand the __attribute__((__aligned__(16))) is necessary in musl.
>>
>> src/thread/pthread_cancel.c
>>
>> static void cancel_handler(int sig, siginfo_t *si, void *ctx)
>> {
>>          pthread_t self = __pthread_self();
>>          ucontext_t *uc = ctx;
>>          uintptr_t pc = uc->uc_mcontext.MC_PC;
>>           ...
>> }
>>
>> musl/arch/loongarch64/bits/signal.h:
>>
>> typedef unsigned long greg_t, gregset_t[32];
>> typedef struct sigcontext {
>>          unsigned long pc;
>>          gregset_t gregs;
>>          unsigned int flags;
>>          unsigned long extcontext[];
>> }mcontext_t;
>>
>> linux/arch/loongarch/include/uapi/asm/sigcontext.h:
>>
>> struct sigcontext {
>>          __u64   sc_pc;
>>          __u64   sc_regs[32];
>>          __u32   sc_flags;
>>          __u64   sc_extcontext[0] __attribute__((__aligned__(16)));
>> };
> This is because ucontext_t is defined without explicit padding before
> uc_mcontext. Add "long __uc_pad;" or similar before it so that the
> offset is explicitly what it's supposed to be rather than a
> consequence ot overalignment.

Add "long __uc_pad;" before uc_mcontext can resolve offset error,
why it is better than sc_extcontext[] __attribute__((__aligned__(16)))?
isn't it more direct to be consistent with kernel?

> Rich


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [musl] add loongarch64 port v3
  2022-05-26  3:07               ` 王洪亮
@ 2022-05-29  6:34                 ` Szabolcs Nagy
  0 siblings, 0 replies; 13+ messages in thread
From: Szabolcs Nagy @ 2022-05-29  6:34 UTC (permalink / raw)
  To: 王洪亮; +Cc: musl

* 王洪亮 <wanghongliang@loongson.cn> [2022-05-26 11:07:42 +0800]:
> 在 2022/5/25 下午8:32, Rich Felker 写道:
> > On Wed, May 25, 2022 at 06:08:23PM +0800, 王洪亮 wrote:
> > > 在 2022/5/24 下午8:32, Rich Felker 写道:
> > > > What we've been trying to say is that there are several cases, none of
> > > > which seem to need it:
> > > > 
> > > > 1. You create an object with declared type struct sigcontext. In this
> > > >     case, the flexible array member at the end is not present at all
> > > >     (because that's how C works) which means there's no extended
> > > >     context which needs additional alignment and probably also means
> > > >     this is not a usable way of creating sigcontext structs.
> > > > 
> > > > 2. You malloc storage for the object with space for the flexible array
> > > >     member. In this case the allocation has alignment max_align_t and
> > > >     everything is fine.
> I don't understand what is alignment max_align_t? I found the max_align_t
> definition in musl,is this it?

it is specified in iso c11. malloc aligns at least to this alignment.

> 
> TYPEDEF struct { long long __ll; long double __ld; } max_align_t;
> 
> I understand if FAM is not specified alignment,FAM is aligned according to
> its type size,why is max_align_t?
> > > > 
> > > > 3. You get the object from the kernel pushing it onto the stack in a
> > > >     signal frame. This is probably actually the only case the type is
> > > >     usable in, and of course it has whatever alignment the kernel gave
> > > >     it.
> > > Specify the __attribute__((__aligned__(16))) in musl,is used to be
> > > consistent with kernel.if I removed the __attribute__((__aligned__(16))),
> > > there is a libc-test fail in pthread_cancel.exe.the reason is that the
> > > offset of uc->uc_mcontext from the start of uc obtained in cancel_handler
> > > is inconsistent with kernel pushing it onto the stack in a signal frame.
> > > so I understand the __attribute__((__aligned__(16))) is necessary in musl.
> > > 
> > > src/thread/pthread_cancel.c
> > > 
> > > static void cancel_handler(int sig, siginfo_t *si, void *ctx)
> > > {
> > >          pthread_t self = __pthread_self();
> > >          ucontext_t *uc = ctx;
> > >          uintptr_t pc = uc->uc_mcontext.MC_PC;
> > >           ...
> > > }
> > > 
> > > musl/arch/loongarch64/bits/signal.h:
> > > 
> > > typedef unsigned long greg_t, gregset_t[32];
> > > typedef struct sigcontext {
> > >          unsigned long pc;
> > >          gregset_t gregs;
> > >          unsigned int flags;
> > >          unsigned long extcontext[];
> > > }mcontext_t;
> > > 
> > > linux/arch/loongarch/include/uapi/asm/sigcontext.h:
> > > 
> > > struct sigcontext {
> > >          __u64   sc_pc;
> > >          __u64   sc_regs[32];
> > >          __u32   sc_flags;
> > >          __u64   sc_extcontext[0] __attribute__((__aligned__(16)));
> > > };
> > This is because ucontext_t is defined without explicit padding before
> > uc_mcontext. Add "long __uc_pad;" or similar before it so that the
> > offset is explicitly what it's supposed to be rather than a
> > consequence ot overalignment.
> 
> Add "long __uc_pad;" before uc_mcontext can resolve offset error,
> why it is better than sc_extcontext[] __attribute__((__aligned__(16)))?
> isn't it more direct to be consistent with kernel?

the aligned attribute is not standard (iso c11 has _Alignas instead).

the kernel does not care, but libc headers must work with all compilers
and c language parsing tools, so if we can specify a struct with the
same abi that the kernel wants but in a standard conform way, then we
should do it that way.

stating the padding explicitly is useful anyway when the exact layout
of a type matters. it is not just about declaring the type but
documenting the abi.

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2022-05-29  6:34 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-05  3:21 [musl] add loongarch64 port v3 王洪亮
2022-05-09  1:34 ` [musl] " 王洪亮
2022-05-11 13:37   ` Rich Felker
2022-05-11 16:08     ` Arnd Bergmann
2022-05-16 14:27 ` [musl] " Rich Felker
2022-05-21  6:38   ` 王洪亮
2022-05-21  8:22     ` Markus Wichmann
2022-05-24  9:08       ` 王洪亮
2022-05-24 12:32         ` Rich Felker
2022-05-25 10:08           ` 王洪亮
2022-05-25 12:32             ` Rich Felker
2022-05-26  3:07               ` 王洪亮
2022-05-29  6:34                 ` Szabolcs Nagy

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