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. --- htl/Makefile | 2 -- htl/Versions | 1 - 2 files changed, 3 deletions(-) (limited to 'htl') diff --git a/htl/Makefile b/htl/Makefile index 38d9f8c590..9adc95e07f 100644 --- a/htl/Makefile +++ b/htl/Makefile @@ -132,8 +132,6 @@ libpthread-routines := pt-attr pt-attr-destroy pt-attr-getdetachstate \ sem-post sem-timedwait sem-trywait sem_unlink \ sem-wait sem-waitfast \ \ - shm-directory \ - \ cancellation \ cthreads-compat \ herrno \ diff --git a/htl/Versions b/htl/Versions index 95496297e3..9506043c62 100644 --- a/htl/Versions +++ b/htl/Versions @@ -168,7 +168,6 @@ libpthread { GLIBC_PRIVATE { __pthread_initialize_minimal; - __shm_directory; __pthread_threads; __cthread_detach; -- cgit 1.4.1