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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-01 10:17:18 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-01 10:17:18 -0700 |
commit | 99f7b025bfadd7fac5216dcfb2a08312804674c0 (patch) | |
tree | b5318d3acc933eb21676e48e3bf7b428295347c2 /arch/x86/kernel | |
parent | a21e40877ad130de837b0394583e4f68dc2ab6c5 (diff) | |
parent | 6cce16f99d7be23cec7cabdf32a8166eec6e5393 (diff) | |
download | linux-99f7b025bfadd7fac5216dcfb2a08312804674c0.tar.gz linux-99f7b025bfadd7fac5216dcfb2a08312804674c0.tar.bz2 linux-99f7b025bfadd7fac5216dcfb2a08312804674c0.zip |
Merge branch 'x86-threadinfo-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 threadinfo changes from Ingo Molnar:
"The main change here is the consolidation/unification of 32 and 64 bit
thread_info handling methods, from Steve Rostedt"
* 'x86-threadinfo-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, threadinfo: Redo "x86: Use inline assembler to get sp"
x86: Clean up dumpstack_64.c code
x86: Keep thread_info on thread stack in x86_32
x86: Prepare removal of previous_esp from i386 thread_info structure
x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386
x86: Nuke the supervisor_stack field in i386 thread_info
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/cpu/common.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/dumpstack_32.c | 44 | ||||
-rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 117 | ||||
-rw-r--r-- | arch/x86/kernel/irq_32.c | 83 | ||||
-rw-r--r-- | arch/x86/kernel/process_32.c | 4 | ||||
-rw-r--r-- | arch/x86/kernel/ptrace.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/smpboot.c | 2 |
7 files changed, 177 insertions, 89 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cca53d88762a..a135239badb7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1079,6 +1079,10 @@ static __init int setup_disablecpuid(char *arg) } __setup("clearcpuid=", setup_disablecpuid); +DEFINE_PER_CPU(unsigned long, kernel_stack) = + (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE; +EXPORT_PER_CPU_SYMBOL(kernel_stack); + #ifdef CONFIG_X86_64 struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table }; struct desc_ptr debug_idt_descr = { NR_VECTORS * 16 - 1, @@ -1095,10 +1099,6 @@ DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); -DEFINE_PER_CPU(unsigned long, kernel_stack) = - (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE; -EXPORT_PER_CPU_SYMBOL(kernel_stack); - DEFINE_PER_CPU(char *, irq_stack_ptr) = init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64; diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index a21d49c071db..5abd4cd4230c 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -16,12 +16,35 @@ #include <asm/stacktrace.h> +static void *is_irq_stack(void *p, void *irq) +{ + if (p < irq || p >= (irq + THREAD_SIZE)) + return NULL; + return irq + THREAD_SIZE; +} + + +static void *is_hardirq_stack(unsigned long *stack, int cpu) +{ + void *irq = per_cpu(hardirq_stack, cpu); + + return is_irq_stack(stack, irq); +} + +static void *is_softirq_stack(unsigned long *stack, int cpu) +{ + void *irq = per_cpu(softirq_stack, cpu); + + return is_irq_stack(stack, irq); +} void dump_trace(struct task_struct *task, struct pt_regs *regs, unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data) { + const unsigned cpu = get_cpu(); int graph = 0; + u32 *prev_esp; if (!task) task = current; @@ -39,18 +62,31 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, for (;;) { struct thread_info *context; + void *end_stack; + + end_stack = is_hardirq_stack(stack, cpu); + if (!end_stack) + end_stack = is_softirq_stack(stack, cpu); - context = (struct thread_info *) - ((unsigned long)stack & (~(THREAD_SIZE - 1))); - bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph); + context = task_thread_info(task); + bp = ops->walk_stack(context, stack, bp, ops, data, + end_stack, &graph); - stack = (unsigned long *)context->previous_esp; + /* Stop if not on irq stack */ + if (!end_stack) + break; + + /* The previous esp is saved on the bottom of the stack */ + prev_esp = (u32 *)(end_stack - THREAD_SIZE); + stack = (unsigned long *)*prev_esp; if (!stack) break; + if (ops->stack(data, "IRQ") < 0) break; touch_nmi_watchdog(); } + put_cpu(); } EXPORT_SYMBOL(dump_trace); diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index addb207dab92..346b1df2412e 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -104,6 +104,45 @@ in_irq_stack(unsigned long *stack, unsigned long *irq_stack, return (stack >= irq_stack && stack < irq_stack_end); } +static const unsigned long irq_stack_size = + (IRQ_STACK_SIZE - 64) / sizeof(unsigned long); + +enum stack_type { + STACK_IS_UNKNOWN, + STACK_IS_NORMAL, + STACK_IS_EXCEPTION, + STACK_IS_IRQ, +}; + +static enum stack_type +analyze_stack(int cpu, struct task_struct *task, + unsigned long *stack, unsigned long **stack_end, char **id) +{ + unsigned long *irq_stack; + unsigned long addr; + unsigned used = 0; + + addr = ((unsigned long)stack & (~(THREAD_SIZE - 1))); + if ((unsigned long)task_stack_page(task) == addr) + return STACK_IS_NORMAL; + + *stack_end = in_exception_stack(cpu, (unsigned long)stack, + &used, id); + if (*stack_end) + return STACK_IS_EXCEPTION; + + *stack_end = (unsigned long *)per_cpu(irq_stack_ptr, cpu); + if (!*stack_end) + return STACK_IS_UNKNOWN; + + irq_stack = *stack_end - irq_stack_size; + + if (in_irq_stack(stack, irq_stack, *stack_end)) + return STACK_IS_IRQ; + + return STACK_IS_UNKNOWN; +} + /* * x86-64 can have up to three kernel stacks: * process stack @@ -116,12 +155,11 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, const struct stacktrace_ops *ops, void *data) { const unsigned cpu = get_cpu(); - unsigned long *irq_stack_end = - (unsigned long *)per_cpu(irq_stack_ptr, cpu); - unsigned used = 0; struct thread_info *tinfo; - int graph = 0; + unsigned long *irq_stack; unsigned long dummy; + int graph = 0; + int done = 0; if (!task) task = current; @@ -143,49 +181,60 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, * exceptions */ tinfo = task_thread_info(task); - for (;;) { + while (!done) { + unsigned long *stack_end; + enum stack_type stype; char *id; - unsigned long *estack_end; - estack_end = in_exception_stack(cpu, (unsigned long)stack, - &used, &id); - if (estack_end) { + stype = analyze_stack(cpu, task, stack, &stack_end, &id); + + /* Default finish unless specified to continue */ + done = 1; + + switch (stype) { + + /* Break out early if we are on the thread stack */ + case STACK_IS_NORMAL: + break; + + case STACK_IS_EXCEPTION: + if (ops->stack(data, id) < 0) break; bp = ops->walk_stack(tinfo, stack, bp, ops, - data, estack_end, &graph); + data, stack_end, &graph); ops->stack(data, "<EOE>"); /* * We link to the next stack via the * second-to-last pointer (index -2 to end) in the * exception stack: */ - stack = (unsigned long *) estack_end[-2]; - continue; - } - if (irq_stack_end) { - unsigned long *irq_stack; - irq_stack = irq_stack_end - - (IRQ_STACK_SIZE - 64) / sizeof(*irq_stack); - - if (in_irq_stack(stack, irq_stack, irq_stack_end)) { - if (ops->stack(data, "IRQ") < 0) - break; - bp = ops->walk_stack(tinfo, stack, bp, - ops, data, irq_stack_end, &graph); - /* - * We link to the next stack (which would be - * the process stack normally) the last - * pointer (index -1 to end) in the IRQ stack: - */ - stack = (unsigned long *) (irq_stack_end[-1]); - irq_stack_end = NULL; - ops->stack(data, "EOI"); - continue; - } + stack = (unsigned long *) stack_end[-2]; + done = 0; + break; + + case STACK_IS_IRQ: + + if (ops->stack(data, "IRQ") < 0) + break; + bp = ops->walk_stack(tinfo, stack, bp, + ops, data, stack_end, &graph); + /* + * We link to the next stack (which would be + * the process stack normally) the last + * pointer (index -1 to end) in the IRQ stack: + */ + stack = (unsigned long *) (stack_end[-1]); + irq_stack = stack_end - irq_stack_size; + ops->stack(data, "EOI"); + done = 0; + break; + + case STACK_IS_UNKNOWN: + ops->stack(data, "UNK"); + break; } - break; } /* diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index d7fcbedc9c43..63ce838e5a54 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -55,16 +55,8 @@ static inline int check_stack_overflow(void) { return 0; } static inline void print_stack_overflow(void) { } #endif -/* - * per-CPU IRQ handling contexts (thread information and stack) - */ -union irq_ctx { - struct thread_info tinfo; - u32 stack[THREAD_SIZE/sizeof(u32)]; -} __attribute__((aligned(THREAD_SIZE))); - -static DEFINE_PER_CPU(union irq_ctx *, hardirq_ctx); -static DEFINE_PER_CPU(union irq_ctx *, softirq_ctx); +DEFINE_PER_CPU(struct irq_stack *, hardirq_stack); +DEFINE_PER_CPU(struct irq_stack *, softirq_stack); static void call_on_stack(void *func, void *stack) { @@ -77,14 +69,26 @@ static void call_on_stack(void *func, void *stack) : "memory", "cc", "edx", "ecx", "eax"); } +/* how to get the current stack pointer from C */ +#define current_stack_pointer ({ \ + unsigned long sp; \ + asm("mov %%esp,%0" : "=g" (sp)); \ + sp; \ +}) + +static inline void *current_stack(void) +{ + return (void *)(current_stack_pointer & ~(THREAD_SIZE - 1)); +} + static inline int execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) { - union irq_ctx *curctx, *irqctx; - u32 *isp, arg1, arg2; + struct irq_stack *curstk, *irqstk; + u32 *isp, *prev_esp, arg1, arg2; - curctx = (union irq_ctx *) current_thread_info(); - irqctx = __this_cpu_read(hardirq_ctx); + curstk = (struct irq_stack *) current_stack(); + irqstk = __this_cpu_read(hardirq_stack); /* * this is where we switch to the IRQ stack. However, if we are @@ -92,13 +96,14 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) * handler) we can't do that and just have to keep using the * current stack (which is the irq stack already after all) */ - if (unlikely(curctx == irqctx)) + if (unlikely(curstk == irqstk)) return 0; - /* build the stack frame on the IRQ stack */ - isp = (u32 *) ((char *)irqctx + sizeof(*irqctx)); - irqctx->tinfo.task = curctx->tinfo.task; - irqctx->tinfo.previous_esp = current_stack_pointer; + isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); + + /* Save the next esp at the bottom of the stack */ + prev_esp = (u32 *)irqstk; + *prev_esp = current_stack_pointer; if (unlikely(overflow)) call_on_stack(print_stack_overflow, isp); @@ -118,46 +123,40 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq) */ void irq_ctx_init(int cpu) { - union irq_ctx *irqctx; + struct irq_stack *irqstk; - if (per_cpu(hardirq_ctx, cpu)) + if (per_cpu(hardirq_stack, cpu)) return; - irqctx = page_address(alloc_pages_node(cpu_to_node(cpu), + irqstk = page_address(alloc_pages_node(cpu_to_node(cpu), THREADINFO_GFP, THREAD_SIZE_ORDER)); - memset(&irqctx->tinfo, 0, sizeof(struct thread_info)); - irqctx->tinfo.cpu = cpu; - irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); - - per_cpu(hardirq_ctx, cpu) = irqctx; + per_cpu(hardirq_stack, cpu) = irqstk; - irqctx = page_address(alloc_pages_node(cpu_to_node(cpu), + irqstk = page_address(alloc_pages_node(cpu_to_node(cpu), THREADINFO_GFP, THREAD_SIZE_ORDER)); - memset(&irqctx->tinfo, 0, sizeof(struct thread_info)); - irqctx->tinfo.cpu = cpu; - irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); - - per_cpu(softirq_ctx, cpu) = irqctx; + per_cpu(softirq_stack, cpu) = irqstk; printk(KERN_DEBUG "CPU %u irqstacks, hard=%p soft=%p\n", - cpu, per_cpu(hardirq_ctx, cpu), per_cpu(softirq_ctx, cpu)); + cpu, per_cpu(hardirq_stack, cpu), per_cpu(softirq_stack, cpu)); } void do_softirq_own_stack(void) { - struct thread_info *curctx; - union irq_ctx *irqctx; - u32 *isp; + struct thread_info *curstk; + struct irq_stack *irqstk; + u32 *isp, *prev_esp; - curctx = current_thread_info(); - irqctx = __this_cpu_read(softirq_ctx); - irqctx->tinfo.task = curctx->task; - irqctx->tinfo.previous_esp = current_stack_pointer; + curstk = current_stack(); + irqstk = __this_cpu_read(softirq_stack); /* build the stack frame on the softirq stack */ - isp = (u32 *) ((char *)irqctx + sizeof(*irqctx)); + isp = (u32 *) ((char *)irqstk + sizeof(*irqstk)); + + /* Push the previous esp onto the stack */ + prev_esp = (u32 *)irqstk; + *prev_esp = current_stack_pointer; call_on_stack(__do_softirq, isp); } diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 0de43e98ce08..7bc86bbe7485 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -314,6 +314,10 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) */ arch_end_context_switch(next_p); + this_cpu_write(kernel_stack, + (unsigned long)task_stack_page(next_p) + + THREAD_SIZE - KERNEL_STACK_OFFSET); + /* * Restore %gs if needed (which is common) */ diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 7461f50d5bb1..678c0ada3b3c 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -184,14 +184,14 @@ unsigned long kernel_stack_pointer(struct pt_regs *regs) { unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1); unsigned long sp = (unsigned long)®s->sp; - struct thread_info *tinfo; + u32 *prev_esp; if (context == (sp & ~(THREAD_SIZE - 1))) return sp; - tinfo = (struct thread_info *)context; - if (tinfo->previous_esp) - return tinfo->previous_esp; + prev_esp = (u32 *)(context); + if (prev_esp) + return (unsigned long)prev_esp; return (unsigned long)regs; } diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 5aad5a370c85..34826934d4a7 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -766,10 +766,10 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) #else clear_tsk_thread_flag(idle, TIF_FORK); initial_gs = per_cpu_offset(cpu); +#endif per_cpu(kernel_stack, cpu) = (unsigned long)task_stack_page(idle) - KERNEL_STACK_OFFSET + THREAD_SIZE; -#endif early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); initial_code = (unsigned long)start_secondary; stack_start = idle->thread.sp; |