diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/stacktrace.h | 4 | ||||
| -rw-r--r-- | arch/mips/kernel/process.c | 19 | ||||
| -rw-r--r-- | arch/mips/oprofile/Makefile | 2 | ||||
| -rw-r--r-- | arch/mips/oprofile/backtrace.c | 175 | ||||
| -rw-r--r-- | arch/mips/oprofile/common.c | 1 | ||||
| -rw-r--r-- | arch/mips/oprofile/op_impl.h | 2 | ||||
| -rw-r--r-- | arch/x86/oprofile/backtrace.c | 56 | ||||
| -rw-r--r-- | arch/x86/oprofile/nmi_int.c | 14 |
8 files changed, 254 insertions, 19 deletions
diff --git a/arch/mips/include/asm/stacktrace.h b/arch/mips/include/asm/stacktrace.h index 0bf82818aa53..780ee2c2a2ac 100644 --- a/arch/mips/include/asm/stacktrace.h +++ b/arch/mips/include/asm/stacktrace.h @@ -7,6 +7,10 @@ extern int raw_show_trace; extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, unsigned long pc, unsigned long *ra); +extern unsigned long unwind_stack_by_address(unsigned long stack_page, + unsigned long *sp, + unsigned long pc, + unsigned long *ra); #else #define raw_show_trace 1 static inline unsigned long unwind_stack(struct task_struct *task, diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index d2112d3cf115..c28fbe6107bc 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -373,18 +373,18 @@ unsigned long thread_saved_pc(struct task_struct *tsk) #ifdef CONFIG_KALLSYMS -/* used by show_backtrace() */ -unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, - unsigned long pc, unsigned long *ra) +/* generic stack unwinding function */ +unsigned long notrace unwind_stack_by_address(unsigned long stack_page, + unsigned long *sp, + unsigned long pc, + unsigned long *ra) { - unsigned long stack_page; struct mips_frame_info info; unsigned long size, ofs; int leaf; extern void ret_from_irq(void); extern void ret_from_exception(void); - stack_page = (unsigned long)task_stack_page(task); if (!stack_page) return 0; @@ -443,6 +443,15 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, *ra = 0; return __kernel_text_address(pc) ? pc : 0; } +EXPORT_SYMBOL(unwind_stack_by_address); + +/* used by show_backtrace() */ +unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, + unsigned long pc, unsigned long *ra) +{ + unsigned long stack_page = (unsigned long)task_stack_page(task); + return unwind_stack_by_address(stack_page, sp, pc, ra); +} #endif /* diff --git a/arch/mips/oprofile/Makefile b/arch/mips/oprofile/Makefile index 4b9d7044e26c..29f2f13eb31c 100644 --- a/arch/mips/oprofile/Makefile +++ b/arch/mips/oprofile/Makefile @@ -8,7 +8,7 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \ oprofilefs.o oprofile_stats.o \ timer_int.o ) -oprofile-y := $(DRIVER_OBJS) common.o +oprofile-y := $(DRIVER_OBJS) common.o backtrace.o oprofile-$(CONFIG_CPU_MIPS32) += op_model_mipsxx.o oprofile-$(CONFIG_CPU_MIPS64) += op_model_mipsxx.o diff --git a/arch/mips/oprofile/backtrace.c b/arch/mips/oprofile/backtrace.c new file mode 100644 index 000000000000..6854ed5097d2 --- /dev/null +++ b/arch/mips/oprofile/backtrace.c @@ -0,0 +1,175 @@ +#include <linux/oprofile.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/uaccess.h> +#include <asm/ptrace.h> +#include <asm/stacktrace.h> +#include <linux/stacktrace.h> +#include <linux/kernel.h> +#include <asm/sections.h> +#include <asm/inst.h> + +struct stackframe { + unsigned long sp; + unsigned long pc; + unsigned long ra; +}; + +static inline int get_mem(unsigned long addr, unsigned long *result) +{ + unsigned long *address = (unsigned long *) addr; + if (!access_ok(VERIFY_READ, addr, sizeof(unsigned long))) + return -1; + if (__copy_from_user_inatomic(result, address, sizeof(unsigned long))) + return -3; + return 0; +} + +/* + * These two instruction helpers were taken from process.c + */ +static inline int is_ra_save_ins(union mips_instruction *ip) +{ + /* sw / sd $ra, offset($sp) */ + return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) + && ip->i_format.rs == 29 && ip->i_format.rt == 31; +} + +static inline int is_sp_move_ins(union mips_instruction *ip) +{ + /* addiu/daddiu sp,sp,-imm */ + if (ip->i_format.rs != 29 || ip->i_format.rt != 29) + return 0; + if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) + return 1; + return 0; +} + +/* + * Looks for specific instructions that mark the end of a function. + * This usually means we ran into the code area of the previous function. + */ +static inline int is_end_of_function_marker(union mips_instruction *ip) +{ + /* jr ra */ + if (ip->r_format.func == jr_op && ip->r_format.rs == 31) + return 1; + /* lui gp */ + if (ip->i_format.opcode == lui_op && ip->i_format.rt == 28) + return 1; + return 0; +} + +/* + * TODO for userspace stack unwinding: + * - handle cases where the stack is adjusted inside a function + * (generally doesn't happen) + * - find optimal value for max_instr_check + * - try to find a way to handle leaf functions + */ + +static inline int unwind_user_frame(struct stackframe *old_frame, + const unsigned int max_instr_check) +{ + struct stackframe new_frame = *old_frame; + off_t ra_offset = 0; + size_t stack_size = 0; + unsigned long addr; + + if (old_frame->pc == 0 || old_frame->sp == 0 || old_frame->ra == 0) + return -9; + + for (addr = new_frame.pc; (addr + max_instr_check > new_frame.pc) + && (!ra_offset || !stack_size); --addr) { + union mips_instruction ip; + + if (get_mem(addr, (unsigned long *) &ip)) + return -11; + + if (is_sp_move_ins(&ip)) { + int stack_adjustment = ip.i_format.simmediate; + if (stack_adjustment > 0) + /* This marks the end of the previous function, + which means we overran. */ + break; + stack_size = (unsigned) stack_adjustment; + } else if (is_ra_save_ins(&ip)) { + int ra_slot = ip.i_format.simmediate; + if (ra_slot < 0) + /* This shouldn't happen. */ + break; + ra_offset = ra_slot; + } else if (is_end_of_function_marker(&ip)) + break; + } + + if (!ra_offset || !stack_size) + return -1; + + if (ra_offset) { + new_frame.ra = old_frame->sp + ra_offset; + if (get_mem(new_frame.ra, &(new_frame.ra))) + return -13; + } + + if (stack_size) { + new_frame.sp = old_frame->sp + stack_size; + if (get_mem(new_frame.sp, &(new_frame.sp))) + return -14; + } + + if (new_frame.sp > old_frame->sp) + return -2; + + new_frame.pc = old_frame->ra; + *old_frame = new_frame; + + return 0; +} + +static inline void do_user_backtrace(unsigned long low_addr, + struct stackframe *frame, + unsigned int depth) +{ + const unsigned int max_instr_check = 512; + const unsigned long high_addr = low_addr + THREAD_SIZE; + + while (depth-- && !unwind_user_frame(frame, max_instr_check)) { + oprofile_add_trace(frame->ra); + if (frame->sp < low_addr || frame->sp > high_addr) + break; + } +} + +#ifndef CONFIG_KALLSYMS +static inline void do_kernel_backtrace(unsigned long low_addr, + struct stackframe *frame, + unsigned int depth) { } +#else +static inline void do_kernel_backtrace(unsigned long low_addr, + struct stackframe *frame, + unsigned int depth) +{ + while (depth-- && frame->pc) { + frame->pc = unwind_stack_by_address(low_addr, + &(frame->sp), + frame->pc, + &(frame->ra)); + oprofile_add_trace(frame->ra); + } +} +#endif + +void notrace op_mips_backtrace(struct pt_regs *const regs, unsigned int depth) +{ + struct stackframe frame = { .sp = regs->regs[29], + .pc = regs->cp0_epc, + .ra = regs->regs[31] }; + const int userspace = user_mode(regs); + const unsigned long low_addr = ALIGN(frame.sp, THREAD_SIZE); + + if (userspace) + do_user_backtrace(low_addr, &frame, depth); + else + do_kernel_backtrace(low_addr, &frame, depth); +} diff --git a/arch/mips/oprofile/common.c b/arch/mips/oprofile/common.c index f9eb1aba6345..d1f2d4c52d42 100644 --- a/arch/mips/oprofile/common.c +++ b/arch/mips/oprofile/common.c @@ -115,6 +115,7 @@ int __init oprofile_arch_init(struct oprofile_operations *ops) ops->start = op_mips_start; ops->stop = op_mips_stop; ops->cpu_type = lmodel->cpu_type; + ops->backtrace = op_mips_backtrace; printk(KERN_INFO "oprofile: using %s performance monitoring.\n", lmodel->cpu_type); diff --git a/arch/mips/oprofile/op_impl.h b/arch/mips/oprofile/op_impl.h index f04b54fb37d1..7c2da27ece04 100644 --- a/arch/mips/oprofile/op_impl.h +++ b/arch/mips/oprofile/op_impl.h @@ -36,4 +36,6 @@ struct op_mips_model { unsigned char num_counters; }; +void op_mips_backtrace(struct pt_regs * const regs, unsigned int depth); + #endif diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index a5b64ab4cd6e..32f78eb46744 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -11,10 +11,12 @@ #include <linux/oprofile.h> #include <linux/sched.h> #include <linux/mm.h> +#include <linux/compat.h> +#include <linux/highmem.h> + #include <asm/ptrace.h> #include <asm/uaccess.h> #include <asm/stacktrace.h> -#include <linux/compat.h> static int backtrace_stack(void *data, char *name) { @@ -36,17 +38,53 @@ static struct stacktrace_ops backtrace_ops = { .walk_stack = print_context_stack, }; +/* from arch/x86/kernel/cpu/perf_event.c: */ + +/* + * best effort, GUP based copy_from_user() that assumes IRQ or NMI context + */ +static unsigned long +copy_from_user_nmi(void *to, const void __user *from, unsigned long n) +{ + unsigned long offset, addr = (unsigned long)from; + unsigned long size, len = 0; + struct page *page; + void *map; + int ret; + + do { + ret = __get_user_pages_fast(addr, 1, 0, &page); + if (!ret) + break; + + offset = addr & (PAGE_SIZE - 1); + size = min(PAGE_SIZE - offset, n - len); + + map = kmap_atomic(page); + memcpy(to, map+offset, size); + kunmap_atomic(map); + put_page(page); + + len += size; + to += size; + addr += size; + + } while (len < n); + + return len; +} + #ifdef CONFIG_COMPAT static struct stack_frame_ia32 * dump_user_backtrace_32(struct stack_frame_ia32 *head) { + /* Also check accessibility of one struct frame_head beyond: */ struct stack_frame_ia32 bufhead[2]; struct stack_frame_ia32 *fp; + unsigned long bytes; - /* Also check accessibility of one struct frame_head beyond */ - if (!access_ok(VERIFY_READ, head, sizeof(bufhead))) - return NULL; - if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead))) + bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead)); + if (bytes != sizeof(bufhead)) return NULL; fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame); @@ -87,12 +125,12 @@ x86_backtrace_32(struct pt_regs * const regs, unsigned int depth) static struct stack_frame *dump_user_backtrace(struct stack_frame *head) { + /* Also check accessibility of one struct frame_head beyond: */ struct stack_frame bufhead[2]; + unsigned long bytes; - /* Also check accessibility of one struct stack_frame beyond */ - if (!access_ok(VERIFY_READ, head, sizeof(bufhead))) - return NULL; - if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead))) + bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead)); + if (bytes != sizeof(bufhead)) return NULL; oprofile_add_trace(bufhead[0].return_address); diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index cf9750004a08..68894fdc034b 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -112,8 +112,10 @@ static void nmi_cpu_start(void *dummy) static int nmi_start(void) { get_online_cpus(); - on_each_cpu(nmi_cpu_start, NULL, 1); ctr_running = 1; + /* make ctr_running visible to the nmi handler: */ + smp_mb(); + on_each_cpu(nmi_cpu_start, NULL, 1); put_online_cpus(); return 0; } @@ -504,15 +506,18 @@ static int nmi_setup(void) nmi_enabled = 0; ctr_running = 0; - barrier(); + /* make variables visible to the nmi handler: */ + smp_mb(); err = register_die_notifier(&profile_exceptions_nb); if (err) goto fail; get_online_cpus(); register_cpu_notifier(&oprofile_cpu_nb); - on_each_cpu(nmi_cpu_setup, NULL, 1); nmi_enabled = 1; + /* make nmi_enabled visible to the nmi handler: */ + smp_mb(); + on_each_cpu(nmi_cpu_setup, NULL, 1); put_online_cpus(); return 0; @@ -531,7 +536,8 @@ static void nmi_shutdown(void) nmi_enabled = 0; ctr_running = 0; put_online_cpus(); - barrier(); + /* make variables visible to the nmi handler: */ + smp_mb(); unregister_die_notifier(&profile_exceptions_nb); msrs = &get_cpu_var(cpu_msrs); model->shutdown(msrs); |