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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-10 10:17:09 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-10 10:17:09 -0700 |
commit | d82991a8688ad128b46db1b42d5d84396487a508 (patch) | |
tree | a0743d346c23df3dd057c89b83100c09a376224a /arch/arm/kernel | |
parent | f4e5b30d809d3882c69f43b5c90779af033d40c4 (diff) | |
parent | ccba8b64452b8dbf2c9670de026d00f519bb5da0 (diff) | |
download | linux-d82991a8688ad128b46db1b42d5d84396487a508.tar.gz linux-d82991a8688ad128b46db1b42d5d84396487a508.tar.bz2 linux-d82991a8688ad128b46db1b42d5d84396487a508.zip |
Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull restartable sequence support from Thomas Gleixner:
"The restartable sequences syscall (finally):
After a lot of back and forth discussion and massive delays caused by
the speculative distraction of maintainers, the core set of
restartable sequences has finally reached a consensus.
It comes with the basic non disputed core implementation along with
support for arm, powerpc and x86 and a full set of selftests
It was exposed to linux-next earlier this week, so it does not fully
comply with the merge window requirements, but there is really no
point to drag it out for yet another cycle"
* 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq/selftests: Provide Makefile, scripts, gitignore
rseq/selftests: Provide parametrized tests
rseq/selftests: Provide basic percpu ops test
rseq/selftests: Provide basic test
rseq/selftests: Provide rseq library
selftests/lib.mk: Introduce OVERRIDE_TARGETS
powerpc: Wire up restartable sequences system call
powerpc: Add syscall detection for restartable sequences
powerpc: Add support for restartable sequences
x86: Wire up restartable sequence system call
x86: Add support for restartable sequences
arm: Wire up restartable sequences system call
arm: Add syscall detection for restartable sequences
arm: Add restartable sequences support
rseq: Introduce restartable sequences system call
uapi/headers: Provide types_32_64.h
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/entry-common.S | 25 | ||||
-rw-r--r-- | arch/arm/kernel/signal.c | 14 |
2 files changed, 33 insertions, 6 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 20df608bf343..106a1466518d 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -39,12 +39,13 @@ saved_pc .req lr .section .entry.text,"ax",%progbits .align 5 -#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING)) +#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING) || \ + IS_ENABLED(CONFIG_DEBUG_RSEQ)) /* * This is the fast syscall return path. We do as little as possible here, * such as avoiding writing r0 to the stack. We only use this path if we - * have tracing and context tracking disabled - the overheads from those - * features make this path too inefficient. + * have tracing, context tracking and rseq debug disabled - the overheads + * from those features make this path too inefficient. */ ret_fast_syscall: UNWIND(.fnstart ) @@ -71,14 +72,20 @@ fast_work_pending: /* fall through to work_pending */ #else /* - * The "replacement" ret_fast_syscall for when tracing or context tracking - * is enabled. As we will need to call out to some C functions, we save - * r0 first to avoid needing to save registers around each C function call. + * The "replacement" ret_fast_syscall for when tracing, context tracking, + * or rseq debug is enabled. As we will need to call out to some C functions, + * we save r0 first to avoid needing to save registers around each C function + * call. */ ret_fast_syscall: UNWIND(.fnstart ) UNWIND(.cantunwind ) str r0, [sp, #S_R0 + S_OFF]! @ save returned r0 +#if IS_ENABLED(CONFIG_DEBUG_RSEQ) + /* do_rseq_syscall needs interrupts enabled. */ + mov r0, sp @ 'regs' + bl do_rseq_syscall +#endif disable_irq_notrace @ disable interrupts ldr r2, [tsk, #TI_ADDR_LIMIT] cmp r2, #TASK_SIZE @@ -113,6 +120,12 @@ ENDPROC(ret_fast_syscall) */ ENTRY(ret_to_user) ret_slow_syscall: +#if IS_ENABLED(CONFIG_DEBUG_RSEQ) + /* do_rseq_syscall needs interrupts enabled. */ + enable_irq_notrace @ enable interrupts + mov r0, sp @ 'regs' + bl do_rseq_syscall +#endif disable_irq_notrace @ disable interrupts ENTRY(ret_to_user_from_irq) ldr r2, [tsk, #TI_ADDR_LIMIT] diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index bd8810d4acb3..f09e9d66d605 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -541,6 +541,12 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) int ret; /* + * Increment event counter and perform fixup for the pre-signal + * frame. + */ + rseq_signal_deliver(regs); + + /* * Set up the stack frame */ if (ksig->ka.sa.sa_flags & SA_SIGINFO) @@ -660,6 +666,7 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) } else { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + rseq_handle_notify_resume(regs); } } local_irq_disable(); @@ -703,3 +710,10 @@ asmlinkage void addr_limit_check_failed(void) { addr_limit_user_check(); } + +#ifdef CONFIG_DEBUG_RSEQ +asmlinkage void do_rseq_syscall(struct pt_regs *regs) +{ + rseq_syscall(regs); +} +#endif |