From cf007647475b5090819c5fe8da771073145c7334 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 10 Aug 2023 12:54:18 -0700 Subject: ARM: ptrace: Restore syscall restart tracing Since commit 4e57a4ddf6b0 ("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 Cc: Arnd Bergmann Cc: Lecopzer Chen Cc: Oleg Nesterov Cc: linux-arm-kernel@lists.infradead.org Fixes: 4e57a4ddf6b0 ("ARM: 9107/1: syscall: always store thread_info->abi_syscall") Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20230810195422.2304827-1-keescook@chromium.org Signed-off-by: Kees Cook --- arch/arm/kernel/entry-common.S | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index bcc4c9ec3aa4..5c31e9de7a60 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -90,6 +90,7 @@ 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) -- cgit