diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 49d9f9305247..978eac57e04a 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -51,23 +51,15 @@ ret_fast_syscall: fast_work_pending: str r0, [sp, #S_R0+S_OFF]! @ returned r0 work_pending: - tst r1, #_TIF_NEED_RESCHED - bne work_resched - /* - * TIF_SIGPENDING or TIF_NOTIFY_RESUME must've been set if we got here - */ - ldr r2, [sp, #S_PSR] mov r0, sp @ 'regs' - tst r2, #15 @ are we returning to user mode? - bne no_work_pending @ no? just leave, then... mov r2, why @ 'syscall' - tst r1, #_TIF_SIGPENDING @ delivering a signal? - movne why, #0 @ prevent further restarts - bl do_notify_resume - b ret_slow_syscall @ Check work again + bl do_work_pending + cmp r0, #0 + beq no_work_pending + movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE) + ldmia sp, {r0 - r6} @ have to reload r0 - r6 + b local_restart @ ... and off we go -work_resched: - bl schedule /* * "slow" syscall return path. "why" tells us if this was a real syscall. */ @@ -409,6 +401,7 @@ ENTRY(vector_swi) eor scno, scno, #__NR_SYSCALL_BASE @ check OS number #endif +local_restart: ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing stmdb sp!, {r4, r5} @ push fifth and sixth args @@ -450,7 +443,8 @@ __sys_trace: mov scno, r0 @ syscall number (possibly new) add r1, sp, #S_R0 + S_OFF @ pointer to regs cmp scno, #NR_syscalls @ check upper syscall limit - ldmccia r1, {r0 - r3} @ have to reload r0 - r3 + ldmccia r1, {r0 - r6} @ have to reload r0 - r6 + stmccia sp, {r4, r5} @ and update the stack args ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine b 2b diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index dab711e6e1ca..3e0fc5f7ed4b 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 536c5d6b340b..f27789e4e38a 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -27,7 +27,6 @@ */ #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE)) #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE)) -#define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE) /* * With EABI, the syscall number has to be loaded into r7. @@ -47,18 +46,6 @@ const unsigned long sigreturn_codes[7] = { MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN, }; -/* - * Either we support OABI only, or we have EABI with the OABI - * compat layer enabled. In the later case we don't know if - * user space is EABI or not, and if not we must not clobber r7. - * Always using the OABI syscall solves that issue and works for - * all those cases. - */ -const unsigned long syscall_restart_code[2] = { - SWI_SYS_RESTART, /* swi __NR_restart_syscall */ - 0xe49df004, /* ldr pc, [sp], #4 */ -}; - /* * atomically swap in the new signal mask, and wait for a signal. */ @@ -582,12 +569,13 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, * the kernel can handle, and then we build all the user-level signal handling * stack-frames in one go after that. */ -static void do_signal(struct pt_regs *regs, int syscall) +static int do_signal(struct pt_regs *regs, int syscall) { unsigned int retval = 0, continue_addr = 0, restart_addr = 0; struct k_sigaction ka; siginfo_t info; int signr; + int restart = 0; /* * If we were from a system call, check for system call restarting... @@ -602,15 +590,15 @@ static void do_signal(struct pt_regs *regs, int syscall) * debugger will see the already changed PSW. */ switch (retval) { + case -ERESTART_RESTARTBLOCK: + restart -= 2; case -ERESTARTNOHAND: case -ERESTARTSYS: case -ERESTARTNOINTR: + restart++; regs->ARM_r0 = regs->ARM_ORIG_r0; regs->ARM_pc = restart_addr; break; - case -ERESTART_RESTARTBLOCK: - regs->ARM_r0 = -EINTR; - break; } } @@ -619,14 +607,17 @@ static void do_signal(struct pt_regs *regs, int syscall) * point the debugger may change all our registers ... */ signr = get_signal_to_deliver(&info, &ka, regs, NULL); + /* + * Depending on the signal settings we may need to revert the + * decision to restart the system call. But skip this if a + * debugger has chosen to restart at a different PC. + */ + if (regs->ARM_pc != restart_addr) + restart = 0; if (signr > 0) { - /* - * Depending on the signal settings we may need to revert the - * decision to restart the system call. But skip this if a - * debugger has chosen to restart at a different PC. - */ - if (regs->ARM_pc == restart_addr) { - if (retval == -ERESTARTNOHAND + if (unlikely(restart)) { + if (retval == -ERESTARTNOHAND || + retval == -ERESTART_RESTARTBLOCK || (retval == -ERESTARTSYS && !(ka.sa.sa_flags & SA_RESTART))) { regs->ARM_r0 = -EINTR; @@ -635,52 +626,43 @@ static void do_signal(struct pt_regs *regs, int syscall) } handle_signal(signr, &ka, &info, regs); - return; - } - - if (syscall) { - /* - * Handle restarting a different system call. As above, - * if a debugger has chosen to restart at a different PC, - * ignore the restart. - */ - if (retval == -ERESTART_RESTARTBLOCK - && regs->ARM_pc == continue_addr) { - if (thumb_mode(regs)) { - regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE; - regs->ARM_pc -= 2; - } else { -#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT) - regs->ARM_r7 = __NR_restart_syscall; - regs->ARM_pc -= 4; -#else - u32 __user *usp; - - regs->ARM_sp -= 4; - usp = (u32 __user *)regs->ARM_sp; - - if (put_user(regs->ARM_pc, usp) == 0) { - regs->ARM_pc = KERN_RESTART_CODE; - } else { - regs->ARM_sp += 4; - force_sigsegv(0, current); - } -#endif - } - } + return 0; } restore_saved_sigmask(); + if (unlikely(restart)) + regs->ARM_pc = continue_addr; + return restart; } -asmlinkage void -do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) +asmlinkage int +do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) { - if (thread_flags & _TIF_SIGPENDING) - do_signal(regs, syscall); - - if (thread_flags & _TIF_NOTIFY_RESUME) { - clear_thread_flag(TIF_NOTIFY_RESUME); - tracehook_notify_resume(regs); - } + do { + if (likely(thread_flags & _TIF_NEED_RESCHED)) { + schedule(); + } else { + if (unlikely(!user_mode(regs))) + return 0; + local_irq_enable(); + if (thread_flags & _TIF_SIGPENDING) { + int restart = do_signal(regs, syscall); + if (unlikely(restart)) { + /* + * Restart without handlers. + * Deal with it without leaving + * the kernel space. + */ + return restart; + } + syscall = 0; + } else { + clear_thread_flag(TIF_NOTIFY_RESUME); + tracehook_notify_resume(regs); + } + } + local_irq_disable(); + thread_flags = current_thread_info()->flags; + } while (thread_flags & _TIF_WORK_MASK); + return 0; } diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h index 6fcfe8398aa4..5ff067b7c752 100644 --- a/arch/arm/kernel/signal.h +++ b/arch/arm/kernel/signal.h @@ -8,7 +8,5 @@ * published by the Free Software Foundation. */ #define KERN_SIGRETURN_CODE (CONFIG_VECTORS_BASE + 0x00000500) -#define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes)) extern const unsigned long sigreturn_codes[7]; -extern const unsigned long syscall_restart_code[2]; diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 7978d4f0f3ae..f7945218b8c6 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -844,8 +844,6 @@ void __init early_trap_init(void *vectors_base) */ memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), sigreturn_codes, sizeof(sigreturn_codes)); - memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), - syscall_restart_code, sizeof(syscall_restart_code)); flush_icache_range(vectors, vectors + PAGE_SIZE); modify_domain(DOMAIN_USER, DOMAIN_CLIENT);