From e9fed2438a1ff475821864f906286dc58907f06b Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 3 Feb 2021 08:55:13 -0300 Subject: linux: Require /dev/shm as the shared memory file system Previously, glibc would pick an arbitrary tmpfs file system from /proc/mounts if /dev/shm was not available. This could lead to an unsuitable file system being picked for the backing storage for shm_open, sem_open, and related functions. This patch introduces a new function, __shm_get_name, which builds the file name under the appropriate (now hard-coded) directory. It is called from the various shm_* and sem_* function. Unlike the SHM_GET_NAME macro it replaces, the callers handle the return values and errno updates. shm-directory.c is moved directly into the posix subdirectory because it can be implemented directly using POSIX functionality. It resides in libc because it is needed by both librt and nptl/htl. In the sem_open implementation, tmpfname is initialized directly from a string constant. This happens to remove one alloca call. Checked on x86_64-linux-gnu. --- posix/Versions | 1 + 1 file changed, 1 insertion(+) (limited to 'posix/Versions') diff --git a/posix/Versions b/posix/Versions index 7d06a6d0c0..cfd3819966 100644 --- a/posix/Versions +++ b/posix/Versions @@ -150,5 +150,6 @@ libc { GLIBC_PRIVATE { __libc_fork; __libc_pread; __libc_pwrite; __nanosleep_nocancel; __pause_nocancel; + __shm_get_name; } } -- cgit v1.2.3