Merge branch 'core' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core
diff --git a/arch/mips/include/asm/stacktrace.h b/arch/mips/include/asm/stacktrace.h
index 0bf8281..780ee2c 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 d2112d3..c28fbe6 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -373,18 +373,18 @@
#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 @@
*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 4b9d704..29f2f13 100644
--- a/arch/mips/oprofile/Makefile
+++ b/arch/mips/oprofile/Makefile
@@ -8,7 +8,7 @@
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 0000000..6854ed5
--- /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 f9eb1ab..d1f2d4c 100644
--- a/arch/mips/oprofile/common.c
+++ b/arch/mips/oprofile/common.c
@@ -115,6 +115,7 @@
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 f04b54f..7c2da27 100644
--- a/arch/mips/oprofile/op_impl.h
+++ b/arch/mips/oprofile/op_impl.h
@@ -36,4 +36,6 @@
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 a5b64ab..32f78eb 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 @@
.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 @@
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 cf97500..68894fd 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -112,8 +112,10 @@
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 @@
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 @@
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);
