| Message ID | 1529949285-11013-2-git-send-email-will.deacon@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jun 25, 2018 at 06:54:43PM +0100, Will Deacon wrote: > /* > * Please add new compat syscalls above this comment and update > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 28ad8799406f..1eda9e1a1f4a 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -904,6 +904,7 @@ ENDPROC(el0_error) > ret_fast_syscall: > disable_daif > str x0, [sp, #S_X0] // returned x0 > +#ifndef CONFIG_DEBUG_RSEQ > ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing > and x2, x1, #_TIF_SYSCALL_WORK > cbnz x2, ret_fast_syscall_trace > @@ -911,6 +912,7 @@ ret_fast_syscall: > cbnz x2, work_pending > enable_step_tsk x1, x2 > kernel_exit 0 > +#endif > ret_fast_syscall_trace: > enable_daif > b __sys_trace_return_skipped // we already saved x0 I *think* this is ok, since we re-check the TIF bits in syscall_trace_exit(). This does mean that we'd now always call audit_syscall_exit(), regardless of TIF_AUDIT, but there are already cases when we call that with TIF_AUDIT clear, so I think if that's a problem it's a latent bug. Likewise for audit_syscall_entry(). It seems we're in the same boat as other architectures there, regardless. FWIW, for the entry bits: Acked-by: Mark Rutland <mark.rutland@arm.com> Mark.
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 42c090cf0292..26cb550673b2 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -127,6 +127,7 @@ config ARM64 select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RCU_TABLE_FREE + select HAVE_RSEQ select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index a0baa9af5487..e0d0f5b856e7 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -43,7 +43,7 @@ #define __ARM_NR_compat_cacheflush (__ARM_NR_COMPAT_BASE+2) #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE+5) -#define __NR_compat_syscalls 398 +#define __NR_compat_syscalls 399 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index ef292160748c..0fdc7ef8a776 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -817,6 +817,8 @@ __SYSCALL(__NR_pkey_alloc, sys_pkey_alloc) __SYSCALL(__NR_pkey_free, sys_pkey_free) #define __NR_statx 397 __SYSCALL(__NR_statx, sys_statx) +#define __NR_rseq 398 +__SYSCALL(__NR_rseq, sys_rseq) /* * Please add new compat syscalls above this comment and update diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 28ad8799406f..1eda9e1a1f4a 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -904,6 +904,7 @@ ENDPROC(el0_error) ret_fast_syscall: disable_daif str x0, [sp, #S_X0] // returned x0 +#ifndef CONFIG_DEBUG_RSEQ ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK cbnz x2, ret_fast_syscall_trace @@ -911,6 +912,7 @@ ret_fast_syscall: cbnz x2, work_pending enable_step_tsk x1, x2 kernel_exit 0 +#endif ret_fast_syscall_trace: enable_daif b __sys_trace_return_skipped // we already saved x0 diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 5c338ce5a7fa..9f479c111675 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1656,6 +1656,8 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs) if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT); + + rseq_syscall(regs); } /* diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 511af13e8d8f..e3b1d1b0aee8 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -802,6 +802,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) int usig = ksig->sig; int ret; + rseq_signal_deliver(ksig, regs); + /* * Set up the stack frame */ @@ -940,6 +942,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, if (thread_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + rseq_handle_notify_resume(NULL, regs); } if (thread_flags & _TIF_FOREIGN_FPSTATE)
Implement calls to rseq_signal_deliver, rseq_handle_notify_resume and rseq_syscall so that we can select HAVE_RSEQ on arm64. Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/unistd.h | 2 +- arch/arm64/include/asm/unistd32.h | 2 ++ arch/arm64/kernel/entry.S | 2 ++ arch/arm64/kernel/ptrace.c | 2 ++ arch/arm64/kernel/signal.c | 3 +++ 6 files changed, 11 insertions(+), 1 deletion(-)