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* [musl] BUG fix: mmap pass wrong offset to kernel
@ 2021-11-16  3:56 Minqiang Chen (ptpt52)
  2021-11-16 16:18 ` Rich Felker
  0 siblings, 1 reply; 3+ messages in thread
From: Minqiang Chen (ptpt52) @ 2021-11-16  3:56 UTC (permalink / raw)
  To: musl

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From 146066a9794b8e39c53337b71a8476b86e79e7d4 Mon Sep 17 00:00:00 2001
From: Chen Minqiang <ptpt52@gmail.com>
Date: Mon, 16 Oct 2017 08:57:41 +0800
Subject: [PATCH] musl: fix mmap pass wrong offset to kernel

on 32bit platform for example off_t x=0x8d9eb000, the x/4096 result
is 0xfff8d9eb, but the sys_mmap2() is expecting 0x8d9eb to be pass to

this happens on 32bit platform or 64bit platform when
x > = 0x80000000 (32bit platform)
or
x > = 0x8000000000000000 (64bit platform)

Signed-off-by: Chen Minqiang <ptpt52@gmail.com>
---
 src/mman/mmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mman/mmap.c b/src/mman/mmap.c
index eff88d82..f225cdbb 100644
--- a/src/mman/mmap.c
+++ b/src/mman/mmap.c
@@ -26,7 +26,7 @@ void *__mmap(void *start, size_t len, int prot, int flags, int fd, off_t off)
                __vm_wait();
        }
 #ifdef SYS_mmap2
-       ret = __syscall(SYS_mmap2, start, len, prot, flags, fd, off/UNIT);
+       ret = __syscall(SYS_mmap2, start, len, prot, flags, fd, (unsigned long)off/UNIT);
 #else
        ret = __syscall(SYS_mmap, start, len, prot, flags, fd, off);
 #endif
-- 
2.17.1


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^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-01-09  6:00 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-16  3:56 [musl] BUG fix: mmap pass wrong offset to kernel Minqiang Chen (ptpt52)
2021-11-16 16:18 ` Rich Felker
2022-01-09  6:00   ` Rich Felker

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