Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/arch/arm/oprofile/common.c

  1 /**
  2  * @file common.c
  3  *
  4  * @remark Copyright 2004 Oprofile Authors
  5  * @remark Copyright 2010 ARM Ltd.
  6  * @remark Read the file COPYING
  7  *
  8  * @author Zwane Mwaikambo
  9  * @author Will Deacon [move to perf]
 10  */
 11 
 12 #include <linux/cpumask.h>
 13 #include <linux/init.h>
 14 #include <linux/mutex.h>
 15 #include <linux/oprofile.h>
 16 #include <linux/perf_event.h>
 17 #include <linux/platform_device.h>
 18 #include <linux/slab.h>
 19 #include <asm/stacktrace.h>
 20 #include <linux/uaccess.h>
 21 
 22 #include <asm/perf_event.h>
 23 #include <asm/ptrace.h>
 24 
 25 #ifdef CONFIG_HW_PERF_EVENTS
 26 
 27 /*
 28  * OProfile has a curious naming scheme for the ARM PMUs, but they are
 29  * part of the user ABI so we need to map from the perf PMU name for
 30  * supported PMUs.
 31  */
 32 static struct op_perf_name {
 33         char *perf_name;
 34         char *op_name;
 35 } op_perf_name_map[] = {
 36         { "armv5_xscale1",      "arm/xscale1"   },
 37         { "armv5_xscale2",      "arm/xscale2"   },
 38         { "armv6_1136",         "arm/armv6"     },
 39         { "armv6_1156",         "arm/armv6"     },
 40         { "armv6_1176",         "arm/armv6"     },
 41         { "armv6_11mpcore",     "arm/mpcore"    },
 42         { "armv7_cortex_a8",    "arm/armv7"     },
 43         { "armv7_cortex_a9",    "arm/armv7-ca9" },
 44 };
 45 
 46 char *op_name_from_perf_id(void)
 47 {
 48         int i;
 49         struct op_perf_name names;
 50         const char *perf_name = perf_pmu_name();
 51 
 52         for (i = 0; i < ARRAY_SIZE(op_perf_name_map); ++i) {
 53                 names = op_perf_name_map[i];
 54                 if (!strcmp(names.perf_name, perf_name))
 55                         return names.op_name;
 56         }
 57 
 58         return NULL;
 59 }
 60 #endif
 61 
 62 static int report_trace(struct stackframe *frame, void *d)
 63 {
 64         unsigned int *depth = d;
 65 
 66         if (*depth) {
 67                 oprofile_add_trace(frame->pc);
 68                 (*depth)--;
 69         }
 70 
 71         return *depth == 0;
 72 }
 73 
 74 /*
 75  * The registers we're interested in are at the end of the variable
 76  * length saved register structure. The fp points at the end of this
 77  * structure so the address of this struct is:
 78  * (struct frame_tail *)(xxx->fp)-1
 79  */
 80 struct frame_tail {
 81         struct frame_tail *fp;
 82         unsigned long sp;
 83         unsigned long lr;
 84 } __attribute__((packed));
 85 
 86 static struct frame_tail* user_backtrace(struct frame_tail *tail)
 87 {
 88         struct frame_tail buftail[2];
 89 
 90         /* Also check accessibility of one struct frame_tail beyond */
 91         if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
 92                 return NULL;
 93         if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
 94                 return NULL;
 95 
 96         oprofile_add_trace(buftail[0].lr);
 97 
 98         /* frame pointers should strictly progress back up the stack
 99          * (towards higher addresses) */
100         if (tail + 1 >= buftail[0].fp)
101                 return NULL;
102 
103         return buftail[0].fp-1;
104 }
105 
106 static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
107 {
108         struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
109 
110         if (!user_mode(regs)) {
111                 struct stackframe frame;
112                 arm_get_current_stackframe(regs, &frame);
113                 walk_stackframe(&frame, report_trace, &depth);
114                 return;
115         }
116 
117         while (depth-- && tail && !((unsigned long) tail & 3))
118                 tail = user_backtrace(tail);
119 }
120 
121 int __init oprofile_arch_init(struct oprofile_operations *ops)
122 {
123         /* provide backtrace support also in timer mode: */
124         ops->backtrace          = arm_backtrace;
125 
126         return oprofile_perf_init(ops);
127 }
128 
129 void oprofile_arch_exit(void)
130 {
131         oprofile_perf_exit();
132 }
133 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us