Use openat syscall if available

Some architectures like AArch64 may not have the open syscall because it
was superseded by the openat syscall, so check and use SYS_openat if
SYS_open is not available.

Additionally, Android headers for AArch64 define SYS_open to __NR_open,
even though __NR_open is undefined. Undefine SYS_open in that case so
SYS_openat is used.
This commit is contained in:
Jim Chen
2017-04-19 15:22:10 -04:00
committed by David Goldblatt
parent 4403c9ab44
commit ae248a2160
2 changed files with 8 additions and 0 deletions

View File

@@ -351,6 +351,9 @@ os_overcommits_proc(void) {
#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_open)
fd = (int)syscall(SYS_open, "/proc/sys/vm/overcommit_memory", O_RDONLY);
#elif defined(JEMALLOC_USE_SYSCALL) && defined(SYS_openat)
fd = (int)syscall(SYS_openat,
AT_FDCWD, "/proc/sys/vm/overcommit_memory", O_RDONLY);
#else
fd = open("/proc/sys/vm/overcommit_memory", O_RDONLY);
#endif