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Clamp tuklib_physmem() return value to SIZE_T_MAX.

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On 32bit platforms it is possible to have (much) more physical RAM
than is mappable into single address space.  In this case liblzma
scales the value into a request to mmap more address space than it is
theoretically possible.

Reported and tested by:	pho
Reviewed by:	delphij
Discussed with:	emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
This commit is contained in:
kib 2019-01-06 23:59:04 +00:00
parent f5884709cc
commit be893b4ffd
1 changed files with 5 additions and 1 deletions
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6
contrib/xz/src/common/tuklib_physmem.c
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@ -45,6 +45,7 @@
# include <sys/systemcfg.h>
#elif defined(TUKLIB_PHYSMEM_SYSCONF)
# include <limits.h>
# include <unistd.h>
#elif defined(TUKLIB_PHYSMEM_SYSCTL)
@ -145,13 +146,16 @@ tuklib_physmem(void)
#elif defined(TUKLIB_PHYSMEM_SYSCONF)
const long pagesize = sysconf(_SC_PAGESIZE);
const long pages = sysconf(_SC_PHYS_PAGES);
if (pagesize != -1 && pages != -1)
if (pagesize != -1 && pages != -1) {
// According to docs, pagesize * pages can overflow.
// Simple case is 32-bit box with 4 GiB or more RAM,
// which may report exactly 4 GiB of RAM, and "long"
// being 32-bit will overflow. Casting to uint64_t
// hopefully avoids overflows in the near future.
ret = (uint64_t)pagesize * (uint64_t)pages;
if (ret > SIZE_T_MAX)
ret = SIZE_T_MAX;
}
#elif defined(TUKLIB_PHYSMEM_SYSCTL)
int name[2] = {