ARM: ptrace: Restore syscall restart tracing

[ Upstream commit cf00764747 ]

Since commit 4e57a4ddf6 ("ARM: 9107/1: syscall: always store
thread_info->abi_syscall"), the seccomp selftests "syscall_restart" has
been broken. This was caused by the restart syscall not being stored to
"abi_syscall" during restart setup before branching to the "local_restart"
label. Tracers would see the wrong syscall, and scno would get overwritten
while returning from the TIF_WORK path. Add the missing store.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 4e57a4ddf6 ("ARM: 9107/1: syscall: always store thread_info->abi_syscall")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230810195422.2304827-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kees Cook 2023-08-10 12:54:18 -07:00 committed by Greg Kroah-Hartman
parent ed134f284b
commit 916ca81922
1 changed files with 1 additions and 0 deletions

View File

@ -103,6 +103,7 @@ slow_work_pending:
cmp r0, #0
beq no_work_pending
movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
str scno, [tsk, #TI_ABI_SYSCALL] @ make sure tracers see update
ldmia sp, {r0 - r6} @ have to reload r0 - r6
b local_restart @ ... and off we go
ENDPROC(ret_fast_syscall)