Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH v2 1/2] ARM: ptrace: Restore syscall restart tracing | Date | Thu, 10 Aug 2023 12:54:18 -0700 |
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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 <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: 4e57a4ddf6b0 ("ARM: 9107/1: syscall: always store thread_info->abi_syscall") Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/arm/kernel/entry-common.S | 1 + 1 file changed, 1 insertion(+)
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) -- 2.34.1
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