[glibc] sysvipc: Fix semtimedop for Linux < 5.1 for 64-bit ABI

Adhemerval Zanella azanella@sourceware.org
Wed Sep 30 21:05:19 GMT 2020


https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=2deb7793907c7995b094b3778017c0ef0bd432d5

commit 2deb7793907c7995b094b3778017c0ef0bd432d5
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Wed Sep 30 16:52:19 2020 -0300

    sysvipc: Fix semtimedop for Linux < 5.1 for 64-bit ABI
    
    Both powerpc64 and s390x provides semtimedop through __NR_ipc for
    pre v5.1 kernel.  Neither the y2038 support (7c437d3778) nor the
    attempt to fix an issue for !__ASSUME_DIRECT_SYSVIPC_SYSCALLS
    (aaa12e9ff0) took this in consideration.
    
    This patch fixes it by issuing __NR_semtimedop_time64 iff it is
    defined, otherwise __NR_semtimeop is issued if both
    __ASSUME_DIRECT_SYSVIPC_SYSCALLS it set and __NR_semtimedop is
    define, other __NR_ipc is used instead.  To summarize:
    
      1. For 32-bit architetures __NR_semtimedop_time64 is always
         issued.  The fallback is used only for !__ASSUME_TIME64_SYSCALLS
         and it issues either __NR_ipc or __NR_semtimedop.
    
      2. For 64-bit architecture with wire-up SysV syscall
         (__ASSUME_DIRECT_SYSVIPC_SYSCALLS and __NR_semtimeop defined)
         __NR_semtimeop is issued.
    
      3. Otherwise __NR_ipc is used instead.
    
    Checked on x86_64-linux-gnu, i686-linux-gnu (kernel 4.15 and 5.4),
    powerpc64le (kernel 4.18), and s390x (kernel 4.12).
    
    Reviewed-by: Matheus Castanho <msc@linux.ibm.com>

Diff:
---
 sysdeps/unix/sysv/linux/semtimedop.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/semtimedop.c b/sysdeps/unix/sysv/linux/semtimedop.c
index a9ad922ee2..29647f8ccd 100644
--- a/sysdeps/unix/sysv/linux/semtimedop.c
+++ b/sysdeps/unix/sysv/linux/semtimedop.c
@@ -26,11 +26,15 @@ int
 __semtimedop64 (int semid, struct sembuf *sops, size_t nsops,
 		const struct __timespec64 *timeout)
 {
-#ifndef __NR_semtimedop_time64
-# define __NR_semtimedop_time64 __NR_semtimedop
+  int r;
+#if defined __NR_semtimedop_time64
+  r = INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops, timeout);
+#elif defined __ASSUME_DIRECT_SYSVIPC_SYSCALLS && defined __NR_semtimedop
+  r = INLINE_SYSCALL_CALL (semtimedop, semid, sops, nsops, timeout);
+#else
+  r = INLINE_SYSCALL_CALL (ipc, IPCOP_semtimedop, semid,
+			   SEMTIMEDOP_IPC_ARGS (nsops, sops, timeout));
 #endif
-  int r = INLINE_SYSCALL_CALL (semtimedop_time64, semid, sops, nsops,
-			       timeout);
 
 #ifndef __ASSUME_TIME64_SYSCALLS
   if (r == 0 || errno != ENOSYS)


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