From: harald@redhat.com
To: musl@lists.openwall.com
Cc: Harald Hoyer <harald@redhat.com>
Subject: [musl] [PATCH] Enable linking to a static position independent executable
Date: Tue, 7 Apr 2020 15:17:07 +0200 [thread overview]
Message-ID: <20200407131707.1220892-1-harald@redhat.com> (raw)
In-Reply-To: <20200406220403.3moghw2llo34e6gh@gmail.com>
From: Harald Hoyer <harald@redhat.com>
This also enables address space layout randomization (ASLR).
$ cat hello.c
int main()
{
printf("main = 0x%lxd\n", main);
return 0;
}
$ gcc -static-pie -o hello hello.c -specs musl-gcc.specs
$ ldd hello
statically linked
$ file hello
hello: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), statically linked, BuildID[sha1]=24fe0d02b0558dc37b8ae2268878b118804ae72d, with debug_info, not stripped
$ ./hello
main = 0x7f858c4e72b9d
$ ./hello
main = 0x7f0854d312b9d
$ ./hello
main = 0x7f7179a1d2b9d
$ ./hello
main = 0x7f37f981b2b9d
$ readelf -l hello
Elf file type is DYN (Shared object file)
Entry point 0x1058
There are 9 program headers, starting at offset 64
Program Headers:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000
0x00000000000003c0 0x00000000000003c0 R 0x1000
LOAD 0x0000000000001000 0x0000000000001000 0x0000000000001000
0x0000000000002cce 0x0000000000002cce R E 0x1000
LOAD 0x0000000000004000 0x0000000000004000 0x0000000000004000
0x0000000000001550 0x0000000000001550 R 0x1000
LOAD 0x0000000000005e50 0x0000000000006e50 0x0000000000006e50
0x00000000000002e0 0x00000000000009a0 RW 0x1000
DYNAMIC 0x0000000000005e70 0x0000000000006e70 0x0000000000006e70
0x0000000000000170 0x0000000000000170 RW 0x8
NOTE 0x0000000000000238 0x0000000000000238 0x0000000000000238
0x0000000000000024 0x0000000000000024 R 0x4
GNU_EH_FRAME 0x0000000000004b60 0x0000000000004b60 0x0000000000004b60
0x00000000000001ec 0x00000000000001ec R 0x4
GNU_STACK 0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 RW 0x10
GNU_RELRO 0x0000000000005e50 0x0000000000006e50 0x0000000000006e50
0x00000000000001b0 0x00000000000001b0 R 0x1
Section to Segment mapping:
Segment Sections...
00 .note.gnu.build-id .gnu.hash .dynsym .dynstr .rela.dyn
01 .init .plt .text .fini
02 .rodata .eh_frame_hdr .eh_frame
03 .init_array .fini_array .data.rel.ro .dynamic .got .got.plt .data .bss
04 .dynamic
05 .note.gnu.build-id
06 .eh_frame_hdr
07
08 .init_array .fini_array .data.rel.ro .dynamic .got
---
tools/musl-gcc.specs.sh | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
mode change 100644 => 100755 tools/musl-gcc.specs.sh
diff --git a/tools/musl-gcc.specs.sh b/tools/musl-gcc.specs.sh
old mode 100644
new mode 100755
index 30492574..4d93626a
--- a/tools/musl-gcc.specs.sh
+++ b/tools/musl-gcc.specs.sh
@@ -17,13 +17,13 @@ cat <<EOF
libgcc.a%s %:if-exists(libgcc_eh.a%s)
*startfile:
-%{!shared: $libdir/Scrt1.o} $libdir/crti.o crtbeginS.o%s
+%{shared:;static:$libdir/crt1.o%s; static-pie:$libdir/rcrt1.o%s; pie:$libdir/Scrt1.o%s; :$libdir/crt1.o%s} $libdir/crti.o%s %{static:crtbeginT.o%s; shared|static-pie|pie:crtbeginS.o%s; :crtbegin.o%s}
*endfile:
-crtendS.o%s $libdir/crtn.o
+%{static:crtend.o%s; shared|static-pie|pie:crtendS.o%s; :crtend.o%s} $libdir/crtn.o%s
*link:
--dynamic-linker $ldso -nostdlib %{shared:-shared} %{static:-static} %{rdynamic:-export-dynamic}
+%{!r:--build-id} --no-add-needed %{!static|static-pie:--eh-frame-hdr} --hash-style=gnu %{shared:-shared} %{!shared:%{!static:%{!static-pie:%{rdynamic:-export-dynamic} -dynamic-linker $ldso}} %{static:-static} %{static-pie:-static -pie --no-dynamic-linker -z text}}
*esp_link:
--
2.25.2
next prev parent reply other threads:[~2020-04-07 13:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-06 18:07 [musl] [PATCH] V2 " harald
2020-04-06 22:04 ` Fangrui Song
2020-04-07 8:42 ` Szabolcs Nagy
2020-04-07 13:17 ` harald [this message]
2020-04-23 11:59 ` [musl] [PATCH] " Harald Hoyer
2020-04-24 15:08 ` Rich Felker
2020-04-27 12:24 ` Harald Hoyer
2020-04-27 12:32 ` harald
2020-05-08 9:05 ` Harald Hoyer
2020-08-25 10:52 ` Harald Hoyer
-- strict thread matches above, loose matches on Subject: below --
2020-04-06 17:58 harald
2020-04-06 18:35 ` Harald Hoyer
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