Hello. It turned out to be that on ARM 'syscall_get_nr' call and corresponding userspace proc access '/proc/*/syscall' always return 0 instead of correct syscall number: # cat /proc/*/syscall 0 0xffffffff 0x0 0x0 0x0 0x0 0x0 0xbea33cc0 0xb6f32f2c 0 0x5 0x16e99a8 0x0 0x0 0x0 0xbeec03b4 0xbeec02a0 0xb6cc85e0 0 0x3 0xbeee5d44 0xbeee5d40 0xbeee5d40 0x0 0x0 0xbeee5d3c 0xb6ef40ac 0 0xffffffff 0xbed757f8 0x2 0x0 0x2 0xbed757f8 0xbed757e0 0xb6e4af2c [snip] Where first digit should be not 0, but correct syscall number. The first patch fixes this and the second one does minor tweaks. Roman Pen (2): ARM: entry-common: fix forgotten set of thread_info->syscall ARM: entry-common,ptrace: do not pass scno to syscall_trace_enter arch/arm/kernel/asm-offsets.c | 1 + arch/arm/kernel/entry-common.S | 2 +- arch/arm/kernel/ptrace.c | 6 ++++-- 3 files changed, 6 insertions(+), 3 deletions(-) Signed-off-by: Roman Pen <r.peniaev@xxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> Cc: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Cc: Sekhar Nori <nsekhar@xxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Eric Paris <eparis@xxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: Marc Zyngier <marc.zyngier@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html