libgcc: avoid mmap/munmap hooks in split-stack code on GNU/Linux

* generic-morestack.c: On GNU/Linux use __mmap/__munmap rather
	than mmap/munmap, to avoid hooks.
This commit is contained in:
Ian Lance Taylor 2020-04-03 14:57:18 -07:00
parent bbcdf9bb3f
commit 710d54ed4e
2 changed files with 22 additions and 0 deletions

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@ -1,3 +1,8 @@
2020-04-03 Ian Lance Taylor <iant@golang.org>
* generic-morestack.c: On GNU/Linux use __mmap/__munmap rather
than mmap/munmap, to avoid hooks.
2020-04-03 Jim Johnston <jjohnst@us.ibm.com>
* config/s390/tpf-unwind.h (MIN_PATRANGE, MAX_PATRANGE)

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@ -53,6 +53,23 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#include "generic-morestack.h"
/* Some systems use LD_PRELOAD or similar tricks to add hooks to
mmap/munmap. That breaks this code, because when we call mmap
there is enough stack space for the system call but there is not,
in general, enough stack space to run a hook. At least when using
glibc on GNU/Linux we can avoid the problem by calling __mmap and
__munmap. */
#ifdef __gnu_linux__
extern void *__mmap (void *, size_t, int, int, int, off_t);
extern int __munmap (void *, size_t);
#define mmap __mmap
#define munmap __munmap
#endif /* defined(__gnu_linux__) */
typedef unsigned uintptr_type __attribute__ ((mode (pointer)));
/* This file contains subroutines that are used by code compiled with