diff options
Diffstat (limited to 'arch/arm/kernel/process.c')
| -rw-r--r-- | arch/arm/kernel/process.c | 112 |
1 files changed, 89 insertions, 23 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index f21970316836..94f6b05f9e24 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -32,6 +32,7 @@ #include <linux/hw_breakpoint.h> #include <linux/cpuidle.h> #include <linux/leds.h> +#include <linux/reboot.h> #include <asm/cacheflush.h> #include <asm/idmap.h> @@ -39,6 +40,7 @@ #include <asm/thread_notify.h> #include <asm/stacktrace.h> #include <asm/mach/time.h> +#include <asm/tls.h> #ifdef CONFIG_CC_STACKPROTECTOR #include <linux/stackprotector.h> @@ -112,7 +114,7 @@ void soft_restart(unsigned long addr) BUG(); } -static void null_restart(char mode, const char *cmd) +static void null_restart(enum reboot_mode reboot_mode, const char *cmd) { } @@ -122,7 +124,7 @@ static void null_restart(char mode, const char *cmd) void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); -void (*arm_pm_restart)(char str, const char *cmd) = null_restart; +void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart; EXPORT_SYMBOL_GPL(arm_pm_restart); /* @@ -174,40 +176,64 @@ void arch_cpu_idle(void) default_idle(); } -static char reboot_mode = 'h'; - -int __init reboot_setup(char *str) -{ - reboot_mode = str[0]; - return 1; -} - -__setup("reboot=", reboot_setup); - +/* + * Called by kexec, immediately prior to machine_kexec(). + * + * This must completely disable all secondary CPUs; simply causing those CPUs + * to execute e.g. a RAM-based pin loop is not sufficient. This allows the + * kexec'd kernel to use any and all RAM as it sees fit, without having to + * avoid any code or data used by any SW CPU pin loop. The CPU hotplug + * functionality embodied in disable_nonboot_cpus() to achieve this. + */ void machine_shutdown(void) { -#ifdef CONFIG_SMP - smp_send_stop(); -#endif + disable_nonboot_cpus(); } +/* + * Halting simply requires that the secondary CPUs stop performing any + * activity (executing tasks, handling interrupts). smp_send_stop() + * achieves this. + */ void machine_halt(void) { - machine_shutdown(); + local_irq_disable(); + smp_send_stop(); + local_irq_disable(); while (1); } +/* + * Power-off simply requires that the secondary CPUs stop performing any + * activity (executing tasks, handling interrupts). smp_send_stop() + * achieves this. When the system power is turned off, it will take all CPUs + * with it. + */ void machine_power_off(void) { - machine_shutdown(); + local_irq_disable(); + smp_send_stop(); + if (pm_power_off) pm_power_off(); } +/* + * Restart requires that the secondary CPUs stop performing any activity + * while the primary CPU resets the system. Systems with a single CPU can + * use soft_restart() as their machine descriptor's .restart hook, since that + * will cause the only available CPU to reset. Systems with multiple CPUs must + * provide a HW restart implementation, to ensure that all CPUs reset at once. + * This is required so that any code running after reset on the primary CPU + * doesn't have to co-ordinate with other CPUs to ensure they aren't still + * executing pre-reset code, and using RAM that the primary CPU's code wishes + * to use. Implementing such co-ordination would be essentially impossible. + */ void machine_restart(char *cmd) { - machine_shutdown(); + local_irq_disable(); + smp_send_stop(); arm_pm_restart(reboot_mode, cmd); @@ -343,7 +369,8 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start, clear_ptrace_hw_breakpoint(p); if (clone_flags & CLONE_SETTLS) - thread->tp_value = childregs->ARM_r3; + thread->tp_value[0] = childregs->ARM_r3; + thread->tp_value[1] = get_tpuser(); thread_notify(THREAD_NOTIFY_COPY, thread); @@ -402,16 +429,16 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) } #ifdef CONFIG_MMU +#ifdef CONFIG_KUSER_HELPERS /* * The vectors page is always readable from user space for the - * atomic helpers and the signal restart code. Insert it into the - * gate_vma so that it is visible through ptrace and /proc/<pid>/mem. + * atomic helpers. Insert it into the gate_vma so that it is visible + * through ptrace and /proc/<pid>/mem. */ static struct vm_area_struct gate_vma = { .vm_start = 0xffff0000, .vm_end = 0xffff0000 + PAGE_SIZE, .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC, - .vm_mm = &init_mm, }; static int __init gate_vma_init(void) @@ -435,9 +462,48 @@ int in_gate_area_no_mm(unsigned long addr) { return in_gate_area(NULL, addr); } +#define is_gate_vma(vma) ((vma) == &gate_vma) +#else +#define is_gate_vma(vma) 0 +#endif const char *arch_vma_name(struct vm_area_struct *vma) { - return (vma == &gate_vma) ? "[vectors]" : NULL; + return is_gate_vma(vma) ? "[vectors]" : + (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ? + "[sigpage]" : NULL; +} + +static struct page *signal_page; +extern struct page *get_signal_page(void); + +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +{ + struct mm_struct *mm = current->mm; + unsigned long addr; + int ret; + + if (!signal_page) + signal_page = get_signal_page(); + if (!signal_page) + return -ENOMEM; + + down_write(&mm->mmap_sem); + addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); + if (IS_ERR_VALUE(addr)) { + ret = addr; + goto up_fail; + } + + ret = install_special_mapping(mm, addr, PAGE_SIZE, + VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, + &signal_page); + + if (ret == 0) + mm->context.sigpage = addr; + + up_fail: + up_write(&mm->mmap_sem); + return ret; } #endif |