From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave.Martin@arm.com (Dave Martin) Date: Tue, 1 Aug 2017 14:54:12 +0100 Subject: [PATCH v2 0/2] arm64: Abstract syscallno manipulation Message-ID: <1501595654-4014-1-git-send-email-Dave.Martin@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Changes since v1: * Change the argument of in_syscall() from int sycallno to a struct pt_regs *, since that's more natural for the current callsites. * Add missing #include of . * Minor commit message clarifications. Original blurb: The upper 32 bits of the syscallno field in struct pt_regs are handled inconsistently, being sometimes zero extended and sometimes sign-extended. The reason for this appears to be that they are not intentionally significant at all. This series attempts to clarify this situation by getting rid of the spurious extra bits and adding a symbolic #define and helpers. My current motivation for this series is SVE, which will makes use of the in_syscall() condition to decide when the user SVE register state for a thread can be discarded. The refactoring done by this series also fixes a strange behaviour observable in ftrace when a tracer cancels a syscall in a compat binary. Currently, ftrace traces the syscall number erroneously in this case: cancel-sys32-2142 [001] .... 1740.510558: sys_enter: NR 4294967295 (1, 6a364, e, 0, 0, 85e) instead of the expected: cancel-sys32-2142 [001] .... 1740.510558: sys_enter: NR -1 (1, 6a364, e, 0, 0, 85e) (Native always says -1, as one might expect.) The gdb testsuite reports no regressions resulting from this series. For big-endian, I have only boot-tested, and checked by inspection that the offset of syscallno in pt_regs is transformed in the correct way (+4) compared with little-endian. Dave Martin (2): arm64: syscallno is secretly an int, make it official arm64: Abstract syscallno manipulation arch/arm64/include/asm/processor.h | 2 +- arch/arm64/include/asm/ptrace.h | 30 +++++++++++++++++++++++++++- arch/arm64/kernel/entry.S | 40 ++++++++++++++++++-------------------- arch/arm64/kernel/ptrace.c | 2 +- arch/arm64/kernel/signal.c | 10 +++++----- arch/arm64/kernel/signal32.c | 2 +- arch/arm64/kernel/traps.c | 2 +- 7 files changed, 57 insertions(+), 31 deletions(-) -- 2.1.4