diff options
| -rw-r--r-- | arch/parisc/Kconfig.debug | 11 | ||||
| -rw-r--r-- | arch/parisc/include/asm/thread_info.h | 2 | ||||
| -rw-r--r-- | arch/parisc/kernel/irq.c | 31 | ||||
| -rw-r--r-- | arch/parisc/kernel/vmlinux.lds.S | 2 |
4 files changed, 42 insertions, 4 deletions
diff --git a/arch/parisc/Kconfig.debug b/arch/parisc/Kconfig.debug index bc989e5..08a332f 100644 --- a/arch/parisc/Kconfig.debug +++ b/arch/parisc/Kconfig.debug @@ -13,3 +13,14 @@ config DEBUG_RODATA If in doubt, say "N". endmenu + +config DEBUG_STACKOVERFLOW + bool "Check for stack overflows" + default y + depends on DEBUG_KERNEL + ---help--- + Say Y here if you want to check the overflows of kernel, IRQ + and exception stacks. This option will cause messages of the + stacks in detail when free stack space drops below a certain + limit. + If in doubt, say "N". diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h index 6182832..540c88f 100644 --- a/arch/parisc/include/asm/thread_info.h +++ b/arch/parisc/include/asm/thread_info.h @@ -40,7 +40,7 @@ struct thread_info { /* thread information allocation */ -#define THREAD_SIZE_ORDER 2 +#define THREAD_SIZE_ORDER 2 /* PA-RISC requires at least 16k stack */ /* Be sure to hunt all references to this down when you change the size of * the kernel stack */ #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 8094d3e..61e51ac 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -330,6 +330,34 @@ static inline int eirr_to_irq(unsigned long eirr) return (BITS_PER_LONG - bit) + TIMER_IRQ; } +int sysctl_panic_on_stackoverflow = 1; + +static inline void stack_overflow_check(struct pt_regs *regs) +{ +#ifdef CONFIG_DEBUG_STACKOVERFLOW + #define STACK_MARGIN (256*6) + + /* Our stack starts directly behind the thread_info struct. */ + unsigned long stack_start = (unsigned long) current_thread_info(); + unsigned long sp = regs->gr[30]; + + /* if sr7 != 0, we interrupted a userspace process which we do not want + * to check for stack overflow. We will only check the kernel stack. */ + if (regs->sr[7]) + return; + + if (likely((sp - stack_start) < (THREAD_SIZE - STACK_MARGIN))) + return; + + pr_emerg("stackcheck: %s will most likely overflow kernel stack " + "(sp:%lx, stk bottom-top:%lx-%lx)\n", + current->comm, sp, stack_start, stack_start + THREAD_SIZE); + + if (sysctl_panic_on_stackoverflow) + panic("low stack detected by irq handler - check messages\n"); +#endif +} + /* ONLY called from entry.S:intr_extint() */ void do_cpu_irq_mask(struct pt_regs *regs) { @@ -364,6 +392,7 @@ void do_cpu_irq_mask(struct pt_regs *regs) goto set_out; } #endif + stack_overflow_check(regs); generic_handle_irq(irq); out: @@ -420,6 +449,4 @@ void __init init_IRQ(void) cpu_eiem = EIEM_MASK(TIMER_IRQ); #endif set_eiem(cpu_eiem); /* EIEM : enable all external intr */ - } - diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S index 64a9998..4bb095a 100644 --- a/arch/parisc/kernel/vmlinux.lds.S +++ b/arch/parisc/kernel/vmlinux.lds.S @@ -95,7 +95,7 @@ SECTIONS NOTES /* Data */ - RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE) + RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, PAGE_SIZE) /* PA-RISC locks requires 16-byte alignment */ . = ALIGN(16); |
