diff options
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 111 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 24 | ||||
| -rw-r--r-- | arch/arm/kernel/ftrace.c | 17 | ||||
| -rw-r--r-- | arch/arm/kernel/process.c | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/ptrace.c | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 6 | ||||
| -rw-r--r-- | arch/arm/kernel/signal.c | 114 | ||||
| -rw-r--r-- | arch/arm/kernel/signal.h | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/traps.c | 10 |
10 files changed, 146 insertions, 144 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 0d1851ca6eb..0f82098c9bf 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -244,6 +244,19 @@ svc_preempt: b 1b #endif +__und_fault: + @ Correct the PC such that it is pointing at the instruction + @ which caused the fault. If the faulting instruction was ARM + @ the PC will be pointing at the next instruction, and have to + @ subtract 4. Otherwise, it is Thumb, and the PC will be + @ pointing at the second half of the Thumb instruction. We + @ have to subtract 2. + ldr r2, [r0, #S_PC] + sub r2, r2, r1 + str r2, [r0, #S_PC] + b do_undefinstr +ENDPROC(__und_fault) + .align 5 __und_svc: #ifdef CONFIG_KPROBES @@ -261,25 +274,32 @@ __und_svc: @ @ r0 - instruction @ -#ifndef CONFIG_THUMB2_KERNEL +#ifndef CONFIG_THUMB2_KERNEL ldr r0, [r4, #-4] #else + mov r1, #2 ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2 cmp r0, #0xe800 @ 32-bit instruction if xx >= 0 - ldrhhs r9, [r4] @ bottom 16 bits - orrhs r0, r9, r0, lsl #16 + blo __und_svc_fault + ldrh r9, [r4] @ bottom 16 bits + add r4, r4, #2 + str r4, [sp, #S_PC] + orr r0, r9, r0, lsl #16 #endif - adr r9, BSYM(1f) + adr r9, BSYM(__und_svc_finish) mov r2, r4 bl call_fpe + mov r1, #4 @ PC correction to apply +__und_svc_fault: mov r0, sp @ struct pt_regs *regs - bl do_undefinstr + bl __und_fault @ @ IRQs off again before pulling preserved data off the stack @ -1: disable_irq_notrace +__und_svc_finish: + disable_irq_notrace @ @ restore SPSR and restart the instruction @@ -423,25 +443,33 @@ __und_usr: mov r2, r4 mov r3, r5 + @ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the + @ faulting instruction depending on Thumb mode. + @ r3 = regs->ARM_cpsr @ - @ fall through to the emulation code, which returns using r9 if - @ it has emulated the instruction, or the more conventional lr - @ if we are to treat this as a real undefined instruction - @ - @ r0 - instruction + @ The emulation code returns using r9 if it has emulated the + @ instruction, or the more conventional lr if we are to treat + @ this as a real undefined instruction @ adr r9, BSYM(ret_from_exception) - adr lr, BSYM(__und_usr_unknown) + tst r3, #PSR_T_BIT @ Thumb mode? - itet eq @ explicit IT needed for the 1f label - subeq r4, r2, #4 @ ARM instr at LR - 4 - subne r4, r2, #2 @ Thumb instr at LR - 2 -1: ldreqt r0, [r4] + bne __und_usr_thumb + sub r4, r2, #4 @ ARM instr at LR - 4 +1: ldrt r0, [r4] #ifdef CONFIG_CPU_ENDIAN_BE8 - reveq r0, r0 @ little endian instruction + rev r0, r0 @ little endian instruction #endif - beq call_fpe + @ r0 = 32-bit ARM instruction which caused the exception + @ r2 = PC value for the following instruction (:= regs->ARM_pc) + @ r4 = PC value for the faulting instruction + @ lr = 32-bit undefined instruction function + adr lr, BSYM(__und_usr_fault_32) + b call_fpe + +__und_usr_thumb: @ Thumb instruction + sub r4, r2, #2 @ First half of thumb instr at LR - 2 #if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7 /* * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms @@ -455,7 +483,7 @@ __und_usr: ldr r5, .LCcpu_architecture ldr r5, [r5] cmp r5, #CPU_ARCH_ARMv7 - blo __und_usr_unknown + blo __und_usr_fault_16 @ 16bit undefined instruction /* * The following code won't get run unless the running CPU really is v7, so * coding round the lack of ldrht on older arches is pointless. Temporarily @@ -463,15 +491,18 @@ __und_usr: */ .arch armv6t2 #endif -2: - ARM( ldrht r5, [r4], #2 ) - THUMB( ldrht r5, [r4] ) - THUMB( add r4, r4, #2 ) +2: ldrht r5, [r4] cmp r5, #0xe800 @ 32bit instruction if xx != 0 - blo __und_usr_unknown -3: ldrht r0, [r4] + blo __und_usr_fault_16 @ 16bit undefined instruction +3: ldrht r0, [r2] add r2, r2, #2 @ r2 is PC + 2, make it PC + 4 + str r2, [sp, #S_PC] @ it's a 2x16bit instr, update orr r0, r0, r5, lsl #16 + adr lr, BSYM(__und_usr_fault_32) + @ r0 = the two 16-bit Thumb instructions which caused the exception + @ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc) + @ r4 = PC value for the first 16-bit Thumb instruction + @ lr = 32bit undefined instruction function #if __LINUX_ARM_ARCH__ < 7 /* If the target arch was overridden, change it back: */ @@ -482,17 +513,13 @@ __und_usr: #endif #endif /* __LINUX_ARM_ARCH__ < 7 */ #else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */ - b __und_usr_unknown + b __und_usr_fault_16 #endif - UNWIND(.fnend ) + UNWIND(.fnend) ENDPROC(__und_usr) - @ - @ fallthrough to call_fpe - @ - /* - * The out of line fixup for the ldrt above. + * The out of line fixup for the ldrt instructions above. */ .pushsection .fixup, "ax" .align 2 @@ -524,11 +551,12 @@ ENDPROC(__und_usr) * NEON handler code. * * Emulators may wish to make use of the following registers: - * r0 = instruction opcode. - * r2 = PC+4 + * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb) + * r2 = PC value to resume execution after successful emulation * r9 = normal "successful" return address - * r10 = this threads thread_info structure. + * r10 = this threads thread_info structure * lr = unrecognised instruction return address + * IRQs disabled, FIQs enabled. */ @ @ Fall-through from Thumb-2 __und_usr @@ -659,12 +687,17 @@ ENTRY(no_fp) mov pc, lr ENDPROC(no_fp) -__und_usr_unknown: - enable_irq +__und_usr_fault_32: + mov r1, #4 + b 1f +__und_usr_fault_16: + mov r1, #2 +1: enable_irq mov r0, sp adr lr, BSYM(ret_from_exception) - b do_undefinstr -ENDPROC(__und_usr_unknown) + b __und_fault +ENDPROC(__und_usr_fault_32) +ENDPROC(__und_usr_fault_16) .align 5 __pabt_usr: diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 49d9f930524..978eac57e04 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/ftrace.c b/arch/arm/kernel/ftrace.c index df0bf0c8cb7..34e56647dce 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -179,19 +179,20 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, old = *parent; *parent = return_hooker; - err = ftrace_push_return_trace(old, self_addr, &trace.depth, - frame_pointer); - if (err == -EBUSY) { - *parent = old; - return; - } - trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; /* Only trace if the calling function expects to */ if (!ftrace_graph_entry(&trace)) { - current->curr_ret_stack--; *parent = old; + return; + } + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer); + if (err == -EBUSY) { + *parent = old; + return; } } diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 19c95ea65b2..693b744fd57 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -247,6 +247,7 @@ void machine_shutdown(void) void machine_halt(void) { machine_shutdown(); + local_irq_disable(); while (1); } @@ -268,6 +269,7 @@ void machine_restart(char *cmd) /* Whoops - the platform was unable to reboot. Tell the user! */ printk("Reboot failed -- System halted\n"); + local_irq_disable(); while (1); } diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index dab711e6e1c..3e0fc5f7ed4 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -25,6 +25,7 @@ #include <linux/regset.h> #include <linux/audit.h> #include <linux/tracehook.h> +#include <linux/unistd.h> #include <asm/pgtable.h> #include <asm/traps.h> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index e15d83bb4ea..a81dcecc734 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -508,7 +508,7 @@ void __init dump_machine_table(void) /* can't use cpu_relax() here as it may require MMU setup */; } -int __init arm_add_memory(phys_addr_t start, unsigned long size) +int __init arm_add_memory(phys_addr_t start, phys_addr_t size) { struct membank *bank = &meminfo.bank[meminfo.nr_banks]; @@ -538,7 +538,7 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size) } #endif - bank->size = size & PAGE_MASK; + bank->size = size & ~(phys_addr_t)(PAGE_SIZE - 1); /* * Check whether this memory region has non-zero size or @@ -558,7 +558,7 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size) static int __init early_mem(char *p) { static int usermem __initdata = 0; - unsigned long size; + phys_addr_t size; phys_addr_t start; char *endp; diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 536c5d6b340..f27789e4e38 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. @@ -48,18 +47,6 @@ const unsigned long sigreturn_codes[7] = { }; /* - * 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. */ asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask) @@ -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 6fcfe8398aa..5ff067b7c75 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/smp.c b/arch/arm/kernel/smp.c index aea74f5bc34..ebd8ad274d7 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -563,7 +563,8 @@ void smp_send_stop(void) cpumask_copy(&mask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &mask); - smp_cross_call(&mask, IPI_CPU_STOP); + if (!cpumask_empty(&mask)) + smp_cross_call(&mask, IPI_CPU_STOP); /* Wait up to one second for other CPUs to stop */ timeout = USEC_PER_SEC; diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 8b97d739b17..f7945218b8c 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -402,18 +402,10 @@ static int call_undef_hook(struct pt_regs *regs, unsigned int instr) asmlinkage void __exception do_undefinstr(struct pt_regs *regs) { - unsigned int correction = thumb_mode(regs) ? 2 : 4; unsigned int instr; siginfo_t info; void __user *pc; - /* - * According to the ARM ARM, PC is 2 or 4 bytes ahead, - * depending whether we're in Thumb mode or not. - * Correct this offset. - */ - regs->ARM_pc -= correction; - pc = (void __user *)instruction_pointer(regs); if (processor_mode(regs) == SVC_MODE) { @@ -852,8 +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); |