From 22a46dee24351fd5f4f188ad80554cad79c82524 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 8 Nov 2022 14:15:02 +0100 Subject: Linux: Support __IPC_64 in sysvctl *ctl command arguments (bug 29771) Old applications pass __IPC_64 as part of the command argument because old glibc did not check for unknown commands, and passed through the arguments directly to the kernel, without adding __IPC_64. Applications need to continue doing that for old glibc compatibility, so this commit enables this approach in current glibc. For msgctl and shmctl, if no translation is required, make direct system calls, as we did before the time64 changes. If translation is required, mask __IPC_64 from the command argument. For semctl, the union-in-vararg argument handling means that translation is needed on all architectures. Reviewed-by: Adhemerval Zanella --- sysdeps/unix/sysv/linux/semctl.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'sysdeps/unix/sysv/linux/semctl.c') diff --git a/sysdeps/unix/sysv/linux/semctl.c b/sysdeps/unix/sysv/linux/semctl.c index 77a8130..3458b01 100644 --- a/sysdeps/unix/sysv/linux/semctl.c +++ b/sysdeps/unix/sysv/linux/semctl.c @@ -140,6 +140,13 @@ __semctl64 (int semid, int semnum, int cmd, ...) union semun64 arg64 = { 0 }; va_list ap; + /* Some applications pass the __IPC_64 flag in cmd, to invoke + previously unsupported commands back when there was no EINVAL + error checking in glibc. Mask the flag for the switch statements + below. semctl_syscall adds back the __IPC_64 flag for the actual + system call. */ + cmd &= ~__IPC_64; + /* Get the argument only if required. */ switch (cmd) { -- cgit v1.1