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backtrace.c: Fix word cast to a pointer 

backtrace.c uses a word size provided by libunwind. In some
architectures like MIPS, libunwind makes that word size 64-bit for all
variants of the architecture.

In the lines #90 and #98, backtrace.c tries to do a cast to a pointer,
which fails in all MIPS variants with 32-bit pointers, like MIPS32 or
MIPS64 n32, because it's trying to do a cast from a 64-bit wide variable
to a 32-bit pointer:

Making all in os
make[2]: Entering directory
`/home/test/test/1/output/build/xserver_xorg-server-1.15.1/os'
  CC     WaitFor.lo
  CC     access.lo
  CC     auth.lo
  CC     backtrace.lo
backtrace.c: In function 'xorg_backtrace':
backtrace.c:90:20: error: cast to pointer from integer of different size
[-Werror=int-to-pointer-cast]
	 if (dladdr((void *)(pip.start_ip + off), &dlinfo) &&
dlinfo.dli_fname &&
		    ^
backtrace.c:98:13: error: cast to pointer from integer of different size
[-Werror=int-to-pointer-cast]
	     (void *)(pip.start_ip + off));
	     ^
cc1: some warnings being treated as errors
make[2]: *** [backtrace.lo] Error 1
make[2]: *** Waiting for unfinished jobs....

Making the cast to a pointer-sized integer, and then to a pointer fixes
the problem.

Related:
  https://bugs.freedesktop.org/show_bug.cgi?id=79939

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
(cherry picked from commit baa50f60ac)
This commit is contained in:
Vicente Olivert Riera 2015-01-12 17:10:02 +00:00 committed by Adam Jackson
parent c424458c93
commit 8b7e1f362b
1 changed files with 2 additions and 2 deletions
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4
os/backtrace.c
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@ -87,7 +87,7 @@ xorg_backtrace(void)
procname[1] = 0;
}
if (dladdr((void *)(pip.start_ip + off), &dlinfo) && dlinfo.dli_fname &&
if (dladdr((void *)(uintptr_t)(pip.start_ip + off), &dlinfo) && dlinfo.dli_fname &&
*dlinfo.dli_fname)
filename = dlinfo.dli_fname;
else
@ -95,7 +95,7 @@ xorg_backtrace(void)
ErrorFSigSafe("%u: %s (%s%s+0x%x) [%p]\n", i++, filename, procname,
ret == -UNW_ENOMEM ? "..." : "", (int)off,
(void *)(pip.start_ip + off));
(void *)(uintptr_t)(pip.start_ip + off));
ret = unw_step(&cursor);
if (ret < 0)