Merge branches 'tracing/branch-tracer', 'tracing/fastboot', 'tracing/ftrace', 'tracing/function-return-tracer', 'tracing/power-tracer', 'tracing/powerpc', 'tracing/ring-buffer', 'tracing/stack-tracer' and 'tracing/urgent' into tracing/core
diff --git a/Documentation/ftrace.txt b/Documentation/ftrace.txt
index 753f4de..35a78bc 100644
--- a/Documentation/ftrace.txt
+++ b/Documentation/ftrace.txt
@@ -324,7 +324,7 @@
cat /debug/tracing/trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \
- noblock nostacktrace nosched-tree
+ noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj
To disable one of the options, echo in the option prepended with "no".
@@ -378,6 +378,20 @@
When a trace is recorded, so is the stack of functions.
This allows for back traces of trace sites.
+ userstacktrace - This option changes the trace.
+ It records a stacktrace of the current userspace thread.
+
+ sym-userobj - when user stacktrace are enabled, look up which object the
+ address belongs to, and print a relative address
+ This is especially useful when ASLR is on, otherwise you don't
+ get a chance to resolve the address to object/file/line after the app is no
+ longer running
+
+ The lookup is performed when you read trace,trace_pipe,latency_trace. Example:
+
+ a.out-1623 [000] 40874.465068: /root/a.out[+0x480] <-/root/a.out[+0
+x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
+
sched-tree - TBD (any users??)
diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/tracers/mmiotrace.txt
index 5bbbe20..cde23b4 100644
--- a/Documentation/tracers/mmiotrace.txt
+++ b/Documentation/tracers/mmiotrace.txt
@@ -37,7 +37,7 @@
$ cat /debug/tracing/trace_pipe > mydump.txt &
Start X or whatever.
$ echo "X is up" > /debug/tracing/trace_marker
-$ echo none > /debug/tracing/current_tracer
+$ echo nop > /debug/tracing/current_tracer
Check for lost events.
@@ -66,7 +66,7 @@
do.
Shut down mmiotrace (requires root privileges):
-$ echo none > /debug/tracing/current_tracer
+$ echo nop > /debug/tracing/current_tracer
The 'cat' process exits. If it does not, kill it by issuing 'fg' command and
pressing ctrl+c.
@@ -81,7 +81,9 @@
$ cat /debug/tracing/trace_entries
gives you a number. Approximately double this number and write it back, for
instance:
+$ echo 0 > /debug/tracing/tracing_enabled
$ echo 128000 > /debug/tracing/trace_entries
+$ echo 1 > /debug/tracing/tracing_enabled
Then start again from the top.
If you are doing a trace for a driver project, e.g. Nouveau, you should also
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index b298f7a..e5f2ae8 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h
@@ -7,7 +7,19 @@
#ifndef __ASSEMBLY__
extern void _mcount(void);
-#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ /* reloction of mcount call site is the same as the address */
+ return addr;
+}
+
+struct dyn_arch_ftrace {
+ struct module *mod;
+};
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index e5f14b1..0845488 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -34,11 +34,19 @@
#ifdef __powerpc64__
unsigned int stubs_section; /* Index of stubs section in module */
unsigned int toc_section; /* What section is the TOC? */
-#else
+#ifdef CONFIG_DYNAMIC_FTRACE
+ unsigned long toc;
+ unsigned long tramp;
+#endif
+
+#else /* powerpc64 */
/* Indices of PLT sections within module. */
unsigned int core_plt_section;
unsigned int init_plt_section;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ unsigned long tramp;
#endif
+#endif /* powerpc64 */
/* List of BUG addresses, source line numbers and filenames */
struct list_head bug_list;
@@ -68,6 +76,12 @@
# endif /* MODULE */
#endif
+#ifdef CONFIG_DYNAMIC_FTRACE
+# ifdef MODULE
+ asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
+# endif /* MODULE */
+#endif
+
struct exception_table_entry;
void sort_ex_table(struct exception_table_entry *start,
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index f4b006e..3271cd6 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -9,22 +9,30 @@
#include <linux/spinlock.h>
#include <linux/hardirq.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/list.h>
#include <asm/cacheflush.h>
+#include <asm/code-patching.h>
#include <asm/ftrace.h>
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt , ...) do { } while (0)
+#endif
-static unsigned int ftrace_nop = 0x60000000;
+static unsigned int ftrace_nop = PPC_NOP_INSTR;
#ifdef CONFIG_PPC32
# define GET_ADDR(addr) addr
#else
/* PowerPC64's functions are data that points to the functions */
-# define GET_ADDR(addr) *(unsigned long *)addr
+# define GET_ADDR(addr) (*(unsigned long *)addr)
#endif
@@ -33,12 +41,12 @@
return (int)(addr - ip);
}
-unsigned char *ftrace_nop_replace(void)
+static unsigned char *ftrace_nop_replace(void)
{
return (char *)&ftrace_nop;
}
-unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
{
static unsigned int op;
@@ -68,49 +76,434 @@
# define _ASM_PTR " .long "
#endif
-int
+static int
ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char *new_code)
{
- unsigned replaced;
- unsigned old = *(unsigned *)old_code;
- unsigned new = *(unsigned *)new_code;
- int faulted = 0;
+ unsigned char replaced[MCOUNT_INSN_SIZE];
/*
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
- * as well as code changing.
+ * as well as code changing. We do this by using the
+ * probe_kernel_* functions.
*
* No real locking needed, this code is run through
- * kstop_machine.
+ * kstop_machine, or before SMP starts.
*/
- asm volatile (
- "1: lwz %1, 0(%2)\n"
- " cmpw %1, %5\n"
- " bne 2f\n"
- " stwu %3, 0(%2)\n"
- "2:\n"
- ".section .fixup, \"ax\"\n"
- "3: li %0, 1\n"
- " b 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- _ASM_ALIGN "\n"
- _ASM_PTR "1b, 3b\n"
- ".previous"
- : "=r"(faulted), "=r"(replaced)
- : "r"(ip), "r"(new),
- "0"(faulted), "r"(old)
- : "memory");
- if (replaced != old && replaced != new)
- faulted = 2;
+ /* read the text we want to modify */
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
- if (!faulted)
- flush_icache_range(ip, ip + 8);
+ /* Make sure it is what we expect it to be */
+ if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
+ return -EINVAL;
- return faulted;
+ /* replace the text with the new text */
+ if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ flush_icache_range(ip, ip + 8);
+
+ return 0;
+}
+
+/*
+ * Helper functions that are the same for both PPC64 and PPC32.
+ */
+static int test_24bit_addr(unsigned long ip, unsigned long addr)
+{
+ long diff;
+
+ /*
+ * Can we get to addr from ip in 24 bits?
+ * (26 really, since we mulitply by 4 for 4 byte alignment)
+ */
+ diff = addr - ip;
+
+ /*
+ * Return true if diff is less than 1 << 25
+ * and greater than -1 << 26.
+ */
+ return (diff < (1 << 25)) && (diff > (-1 << 26));
+}
+
+static int is_bl_op(unsigned int op)
+{
+ return (op & 0xfc000003) == 0x48000001;
+}
+
+static int test_offset(unsigned long offset)
+{
+ return (offset + 0x2000000 > 0x3ffffff) || ((offset & 3) != 0);
+}
+
+static unsigned long find_bl_target(unsigned long ip, unsigned int op)
+{
+ static int offset;
+
+ offset = (op & 0x03fffffc);
+ /* make it signed */
+ if (offset & 0x02000000)
+ offset |= 0xfe000000;
+
+ return ip + (long)offset;
+}
+
+static unsigned int branch_offset(unsigned long offset)
+{
+ /* return "bl ip+offset" */
+ return 0x48000001 | (offset & 0x03fffffc);
+}
+
+#ifdef CONFIG_PPC64
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE * 2];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned char jmp[8];
+ unsigned long *ptr = (unsigned long *)&jmp;
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+ int offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* Make sure that that this is still a 24bit jump */
+ if (!is_bl_op(*op)) {
+ printk(KERN_ERR "Not expected bl: opcode is %x\n", *op);
+ return -EINVAL;
+ }
+
+ /* lets find where the pointer goes */
+ tramp = find_bl_target(ip, *op);
+
+ /*
+ * On PPC64 the trampoline looks like:
+ * 0x3d, 0x82, 0x00, 0x00, addis r12,r2, <high>
+ * 0x39, 0x8c, 0x00, 0x00, addi r12,r12, <low>
+ * Where the bytes 2,3,6 and 7 make up the 32bit offset
+ * to the TOC that holds the pointer.
+ * to jump to.
+ * 0xf8, 0x41, 0x00, 0x28, std r2,40(r1)
+ * 0xe9, 0x6c, 0x00, 0x20, ld r11,32(r12)
+ * The actually address is 32 bytes from the offset
+ * into the TOC.
+ * 0xe8, 0x4c, 0x00, 0x28, ld r2,40(r12)
+ */
+
+ DEBUGP("ip:%lx jumps to %lx r2: %lx", ip, tramp, mod->arch.toc);
+
+ /* Find where the trampoline jumps to */
+ if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x",
+ (unsigned)(*ptr >> 32),
+ (unsigned)*ptr);
+
+ offset = (unsigned)jmp[2] << 24 |
+ (unsigned)jmp[3] << 16 |
+ (unsigned)jmp[6] << 8 |
+ (unsigned)jmp[7];
+
+ DEBUGP(" %x ", offset);
+
+ /* get the address this jumps too */
+ tramp = mod->arch.toc + offset + 32;
+ DEBUGP("toc: %lx", tramp);
+
+ if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x\n",
+ (unsigned)(*ptr >> 32),
+ (unsigned)*ptr);
+
+ /* This should match what was called */
+ if (*ptr != GET_ADDR(addr)) {
+ printk(KERN_ERR "addr does not match %lx\n", *ptr);
+ return -EINVAL;
+ }
+
+ /*
+ * We want to nop the line, but the next line is
+ * 0xe8, 0x41, 0x00, 0x28 ld r2,40(r1)
+ * This needs to be turned to a nop too.
+ */
+ if (probe_kernel_read(replaced, (void *)(ip+4), MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ if (*op != 0xe8410028) {
+ printk(KERN_ERR "Next line is not ld! (%08x)\n", *op);
+ return -EINVAL;
+ }
+
+ /*
+ * Milton Miller pointed out that we can not blindly do nops.
+ * If a task was preempted when calling a trace function,
+ * the nops will remove the way to restore the TOC in r2
+ * and the r2 TOC will get corrupted.
+ */
+
+ /*
+ * Replace:
+ * bl <tramp> <==== will be replaced with "b 1f"
+ * ld r2,40(r1)
+ * 1:
+ */
+ op[0] = 0x48000008; /* b +8 */
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ return 0;
+}
+
+#else /* !PPC64 */
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned char jmp[8];
+ unsigned int *ptr = (unsigned int *)&jmp;
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+ int offset;
+
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* Make sure that that this is still a 24bit jump */
+ if (!is_bl_op(*op)) {
+ printk(KERN_ERR "Not expected bl: opcode is %x\n", *op);
+ return -EINVAL;
+ }
+
+ /* lets find where the pointer goes */
+ tramp = find_bl_target(ip, *op);
+
+ /*
+ * On PPC32 the trampoline looks like:
+ * lis r11,sym@ha
+ * addi r11,r11,sym@l
+ * mtctr r11
+ * bctr
+ */
+
+ DEBUGP("ip:%lx jumps to %lx", ip, tramp);
+
+ /* Find where the trampoline jumps to */
+ if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x ", ptr[0], ptr[1]);
+
+ tramp = (ptr[1] & 0xffff) |
+ ((ptr[0] & 0xffff) << 16);
+ if (tramp & 0x8000)
+ tramp -= 0x10000;
+
+ DEBUGP(" %x ", tramp);
+
+ if (tramp != addr) {
+ printk(KERN_ERR
+ "Trampoline location %08lx does not match addr\n",
+ tramp);
+ return -EINVAL;
+ }
+
+ op[0] = PPC_NOP_INSTR;
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ return 0;
+}
+#endif /* PPC64 */
+
+int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *old, *new;
+ unsigned long ip = rec->ip;
+
+ /*
+ * If the calling address is more that 24 bits away,
+ * then we had to use a trampoline to make the call.
+ * Otherwise just update the call site.
+ */
+ if (test_24bit_addr(ip, addr)) {
+ /* within range */
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop_replace();
+ return ftrace_modify_code(ip, old, new);
+ }
+
+ /*
+ * Out of range jumps are called from modules.
+ * We should either already have a pointer to the module
+ * or it has been passed in.
+ */
+ if (!rec->arch.mod) {
+ if (!mod) {
+ printk(KERN_ERR "No module loaded addr=%lx\n",
+ addr);
+ return -EFAULT;
+ }
+ rec->arch.mod = mod;
+ } else if (mod) {
+ if (mod != rec->arch.mod) {
+ printk(KERN_ERR
+ "Record mod %p not equal to passed in mod %p\n",
+ rec->arch.mod, mod);
+ return -EINVAL;
+ }
+ /* nothing to do if mod == rec->arch.mod */
+ } else
+ mod = rec->arch.mod;
+
+ return __ftrace_make_nop(mod, rec, addr);
+
+}
+
+#ifdef CONFIG_PPC64
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE * 2];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned long ip = rec->ip;
+ unsigned long offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE * 2))
+ return -EFAULT;
+
+ /*
+ * It should be pointing to two nops or
+ * b +8; ld r2,40(r1)
+ */
+ if (((op[0] != 0x48000008) || (op[1] != 0xe8410028)) &&
+ ((op[0] != PPC_NOP_INSTR) || (op[1] != PPC_NOP_INSTR))) {
+ printk(KERN_ERR "Expected NOPs but have %x %x\n", op[0], op[1]);
+ return -EINVAL;
+ }
+
+ /* If we never set up a trampoline to ftrace_caller, then bail */
+ if (!rec->arch.mod->arch.tramp) {
+ printk(KERN_ERR "No ftrace trampoline\n");
+ return -EINVAL;
+ }
+
+ /* now calculate a jump to the ftrace caller trampoline */
+ offset = rec->arch.mod->arch.tramp - ip;
+
+ if (test_offset(offset)) {
+ printk(KERN_ERR "REL24 %li out of range!\n",
+ (long int)offset);
+ return -EINVAL;
+ }
+
+ /* Set to "bl addr" */
+ op[0] = branch_offset(offset);
+ /* ld r2,40(r1) */
+ op[1] = 0xe8410028;
+
+ DEBUGP("write to %lx\n", rec->ip);
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE * 2))
+ return -EPERM;
+
+ return 0;
+}
+#else
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned long ip = rec->ip;
+ unsigned long offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* It should be pointing to a nop */
+ if (op[0] != PPC_NOP_INSTR) {
+ printk(KERN_ERR "Expected NOP but have %x\n", op[0]);
+ return -EINVAL;
+ }
+
+ /* If we never set up a trampoline to ftrace_caller, then bail */
+ if (!rec->arch.mod->arch.tramp) {
+ printk(KERN_ERR "No ftrace trampoline\n");
+ return -EINVAL;
+ }
+
+ /* now calculate a jump to the ftrace caller trampoline */
+ offset = rec->arch.mod->arch.tramp - ip;
+
+ if (test_offset(offset)) {
+ printk(KERN_ERR "REL24 %li out of range!\n",
+ (long int)offset);
+ return -EINVAL;
+ }
+
+ /* Set to "bl addr" */
+ op[0] = branch_offset(offset);
+
+ DEBUGP("write to %lx\n", rec->ip);
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ return 0;
+}
+#endif /* CONFIG_PPC64 */
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *old, *new;
+ unsigned long ip = rec->ip;
+
+ /*
+ * If the calling address is more that 24 bits away,
+ * then we had to use a trampoline to make the call.
+ * Otherwise just update the call site.
+ */
+ if (test_24bit_addr(ip, addr)) {
+ /* within range */
+ old = ftrace_nop_replace();
+ new = ftrace_call_replace(ip, addr);
+ return ftrace_modify_code(ip, old, new);
+ }
+
+ /*
+ * Out of range jumps are called from modules.
+ * Being that we are converting from nop, it had better
+ * already have a module defined.
+ */
+ if (!rec->arch.mod) {
+ printk(KERN_ERR "No module loaded\n");
+ return -EINVAL;
+ }
+
+ return __ftrace_make_call(rec, addr);
}
int ftrace_update_ftrace_func(ftrace_func_t func)
@@ -128,10 +521,10 @@
int __init ftrace_dyn_arch_init(void *data)
{
- /* This is running in kstop_machine */
+ /* caller expects data to be zero */
+ unsigned long *p = data;
- ftrace_mcount_set(data);
+ *p = 0;
return 0;
}
-
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index 31982d0..88d9c1d 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -69,10 +69,15 @@
smp_mb();
local_irq_disable();
+ /* Don't trace irqs off for idle */
+ stop_critical_timings();
+
/* check again after disabling irqs */
if (!need_resched() && !cpu_should_die())
ppc_md.power_save();
+ start_critical_timings();
+
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index 2df91a0..f832773 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -22,6 +22,7 @@
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
+#include <linux/ftrace.h>
#include <linux/cache.h>
#include <linux/bug.h>
#include <linux/sort.h>
@@ -53,6 +54,9 @@
r_addend = rela[i].r_addend;
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ _count_relocs++; /* add one for ftrace_caller */
+#endif
return _count_relocs;
}
@@ -306,5 +310,11 @@
return -ENOEXEC;
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ module->arch.tramp =
+ do_plt_call(module->module_core,
+ (unsigned long)ftrace_caller,
+ sechdrs, module);
+#endif
return 0;
}
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 1af2377..8992b03 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -20,6 +20,7 @@
#include <linux/moduleloader.h>
#include <linux/err.h>
#include <linux/vmalloc.h>
+#include <linux/ftrace.h>
#include <linux/bug.h>
#include <asm/module.h>
#include <asm/firmware.h>
@@ -163,6 +164,11 @@
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ /* make the trampoline to the ftrace_caller */
+ relocs++;
+#endif
+
DEBUGP("Looks like a total of %lu stubs, max\n", relocs);
return relocs * sizeof(struct ppc64_stub_entry);
}
@@ -441,5 +447,12 @@
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ me->arch.toc = my_r2(sechdrs, me);
+ me->arch.tramp = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_caller,
+ me);
+#endif
+
return 0;
}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7a146ba..e49a4fd 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -36,6 +36,7 @@
select HAVE_ARCH_TRACEHOOK
select HAVE_GENERIC_DMA_COHERENT if X86_32
select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select USER_STACKTRACE_SUPPORT
config ARCH_DEFCONFIG
string
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 2bb43b4..754a3e0 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -29,7 +29,6 @@
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_RET_TRACER
-#define FTRACE_RET_STACK_SIZE 20
#ifndef __ASSEMBLY__
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index e90e81e..0921b40 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -40,36 +40,8 @@
*/
__u8 supervisor_stack[0];
#endif
-
-#ifdef CONFIG_FUNCTION_RET_TRACER
- /* Index of current stored adress in ret_stack */
- int curr_ret_stack;
- /* Stack of return addresses for return function tracing */
- struct ftrace_ret_stack ret_stack[FTRACE_RET_STACK_SIZE];
- /*
- * Number of functions that haven't been traced
- * because of depth overrun.
- */
- atomic_t trace_overrun;
-#endif
};
-#ifdef CONFIG_FUNCTION_RET_TRACER
-#define INIT_THREAD_INFO(tsk) \
-{ \
- .task = &tsk, \
- .exec_domain = &default_exec_domain, \
- .flags = 0, \
- .cpu = 0, \
- .preempt_count = 1, \
- .addr_limit = KERNEL_DS, \
- .restart_block = { \
- .fn = do_no_restart_syscall, \
- }, \
- .curr_ret_stack = -1,\
- .trace_overrun = ATOMIC_INIT(0) \
-}
-#else
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
@@ -82,7 +54,6 @@
.fn = do_no_restart_syscall, \
}, \
}
-#endif
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 356bb1e..bb137f7 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -350,19 +350,21 @@
unsigned long func)
{
int index;
- struct thread_info *ti = current_thread_info();
+
+ if (!current->ret_stack)
+ return -EBUSY;
/* The return trace stack is full */
- if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) {
- atomic_inc(&ti->trace_overrun);
+ if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
+ atomic_inc(¤t->trace_overrun);
return -EBUSY;
}
- index = ++ti->curr_ret_stack;
+ index = ++current->curr_ret_stack;
barrier();
- ti->ret_stack[index].ret = ret;
- ti->ret_stack[index].func = func;
- ti->ret_stack[index].calltime = time;
+ current->ret_stack[index].ret = ret;
+ current->ret_stack[index].func = func;
+ current->ret_stack[index].calltime = time;
return 0;
}
@@ -373,13 +375,12 @@
{
int index;
- struct thread_info *ti = current_thread_info();
- index = ti->curr_ret_stack;
- *ret = ti->ret_stack[index].ret;
- *func = ti->ret_stack[index].func;
- *time = ti->ret_stack[index].calltime;
- *overrun = atomic_read(&ti->trace_overrun);
- ti->curr_ret_stack--;
+ index = current->curr_ret_stack;
+ *ret = current->ret_stack[index].ret;
+ *func = current->ret_stack[index].func;
+ *time = current->ret_stack[index].calltime;
+ *overrun = atomic_read(¤t->trace_overrun);
+ current->curr_ret_stack--;
}
/*
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index a03e7f6..10786af 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -6,6 +6,7 @@
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
#include <asm/stacktrace.h>
static void save_stack_warning(void *data, char *msg)
@@ -83,3 +84,66 @@
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
+
+struct stack_frame {
+ const void __user *next_fp;
+ unsigned long ret_addr;
+};
+
+static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
+{
+ int ret;
+
+ if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
+ return 0;
+
+ ret = 1;
+ pagefault_disable();
+ if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+ ret = 0;
+ pagefault_enable();
+
+ return ret;
+}
+
+static inline void __save_stack_trace_user(struct stack_trace *trace)
+{
+ const struct pt_regs *regs = task_pt_regs(current);
+ const void __user *fp = (const void __user *)regs->bp;
+
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = regs->ip;
+
+ while (trace->nr_entries < trace->max_entries) {
+ struct stack_frame frame;
+
+ frame.next_fp = NULL;
+ frame.ret_addr = 0;
+ if (!copy_stack_frame(fp, &frame))
+ break;
+ if ((unsigned long)fp < regs->sp)
+ break;
+ if (frame.ret_addr) {
+ trace->entries[trace->nr_entries++] =
+ frame.ret_addr;
+ }
+ if (fp == frame.next_fp)
+ break;
+ fp = frame.next_fp;
+ }
+}
+
+void save_stack_trace_user(struct stack_trace *trace)
+{
+ /*
+ * Trace user stack if we are not a kernel thread
+ */
+ if (current->mm) {
+ __save_stack_trace_user(trace);
+ }
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
diff --git a/fs/seq_file.c b/fs/seq_file.c
index eba2eab..f03220d7 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -357,7 +357,18 @@
}
EXPORT_SYMBOL(seq_printf);
-static char *mangle_path(char *s, char *p, char *esc)
+/**
+ * mangle_path - mangle and copy path to buffer beginning
+ * @s: buffer start
+ * @p: beginning of path in above buffer
+ * @esc: set of characters that need escaping
+ *
+ * Copy the path from @p to @s, replacing each occurrence of character from
+ * @esc with usual octal escape.
+ * Returns pointer past last written character in @s, or NULL in case of
+ * failure.
+ */
+char *mangle_path(char *s, char *p, char *esc)
{
while (s <= p) {
char c = *p++;
@@ -376,6 +387,7 @@
}
return NULL;
}
+EXPORT_SYMBOL_GPL(mangle_path);
/*
* return the absolute path of 'dentry' residing in mount 'mnt'.
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index f7ba4ea..7854d87 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -257,6 +257,7 @@
extern void tracing_start(void);
extern void tracing_stop(void);
+extern void ftrace_off_permanent(void);
extern void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3);
@@ -290,6 +291,7 @@
static inline void tracing_start(void) { }
static inline void tracing_stop(void) { }
+static inline void ftrace_off_permanent(void) { }
static inline int
ftrace_printk(const char *fmt, ...)
{
@@ -323,6 +325,8 @@
};
#ifdef CONFIG_FUNCTION_RET_TRACER
+#define FTRACE_RETFUNC_DEPTH 50
+#define FTRACE_RETSTACK_ALLOC_SIZE 32
/* Type of a callback handler of tracing return function */
typedef void (*trace_function_return_t)(struct ftrace_retfunc *);
@@ -330,6 +334,12 @@
/* The current handler in use */
extern trace_function_return_t ftrace_function_return;
extern void unregister_ftrace_return(void);
+
+extern void ftrace_retfunc_init_task(struct task_struct *t);
+extern void ftrace_retfunc_exit_task(struct task_struct *t);
+#else
+static inline void ftrace_retfunc_init_task(struct task_struct *t) { }
+static inline void ftrace_retfunc_exit_task(struct task_struct *t) { }
#endif
#endif /* _LINUX_FTRACE_H */
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index e097c2e..3bb87a7 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -122,6 +122,7 @@
void tracing_on(void);
void tracing_off(void);
+void tracing_off_permanent(void);
enum ring_buffer_flags {
RB_FL_OVERWRITE = 1 << 0,
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c8e0db4..bee1e93 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1352,6 +1352,17 @@
unsigned long default_timer_slack_ns;
struct list_head *scm_work_list;
+#ifdef CONFIG_FUNCTION_RET_TRACER
+ /* Index of current stored adress in ret_stack */
+ int curr_ret_stack;
+ /* Stack of return addresses for return function tracing */
+ struct ftrace_ret_stack *ret_stack;
+ /*
+ * Number of functions that haven't been traced
+ * because of depth overrun.
+ */
+ atomic_t trace_overrun;
+#endif
};
/*
@@ -2006,18 +2017,6 @@
{
*task_thread_info(p) = *task_thread_info(org);
task_thread_info(p)->task = p;
-
-#ifdef CONFIG_FUNCTION_RET_TRACER
- /*
- * When fork() creates a child process, this function is called.
- * But the child task may not inherit the return adresses traced
- * by the return function tracer because it will directly execute
- * in userspace and will not return to kernel functions its parent
- * used.
- */
- task_thread_info(p)->curr_ret_stack = -1;
- atomic_set(&task_thread_info(p)->trace_overrun, 0);
-#endif
}
static inline unsigned long *end_of_stack(struct task_struct *p)
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index dc50bcc..b3dfa72 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -34,6 +34,7 @@
#define SEQ_SKIP 1
+char *mangle_path(char *s, char *p, char *esc);
int seq_open(struct file *, const struct seq_operations *);
ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
loff_t seq_lseek(struct file *, loff_t, int);
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index b106fd8..1a8cecc 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -15,9 +15,17 @@
struct stack_trace *trace);
extern void print_stack_trace(struct stack_trace *trace, int spaces);
+
+#ifdef CONFIG_USER_STACKTRACE_SUPPORT
+extern void save_stack_trace_user(struct stack_trace *trace);
+#else
+# define save_stack_trace_user(trace) do { } while (0)
+#endif
+
#else
# define save_stack_trace(trace) do { } while (0)
# define save_stack_trace_tsk(tsk, trace) do { } while (0)
+# define save_stack_trace_user(trace) do { } while (0)
# define print_stack_trace(trace, spaces) do { } while (0)
#endif
diff --git a/init/main.c b/init/main.c
index e810196..79213c0 100644
--- a/init/main.c
+++ b/init/main.c
@@ -723,7 +723,7 @@
disable_boot_trace();
rettime = ktime_get();
delta = ktime_sub(rettime, calltime);
- ret.duration = (unsigned long long) delta.tv64 >> 10;
+ ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
trace_boot_ret(&ret, fn);
printk("initcall %pF returned %d after %Ld usecs\n", fn,
ret.result, ret.duration);
diff --git a/kernel/exit.c b/kernel/exit.c
index 35c8ec2..e5ae36e 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1127,7 +1127,6 @@
preempt_disable();
/* causes final put_task_struct in finish_task_switch(). */
tsk->state = TASK_DEAD;
-
schedule();
BUG();
/* Avoid "noreturn function does return". */
diff --git a/kernel/fork.c b/kernel/fork.c
index ac62f43..d6e1a32 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -47,6 +47,7 @@
#include <linux/mount.h>
#include <linux/audit.h>
#include <linux/memcontrol.h>
+#include <linux/ftrace.h>
#include <linux/profile.h>
#include <linux/rmap.h>
#include <linux/acct.h>
@@ -139,6 +140,7 @@
prop_local_destroy_single(&tsk->dirties);
free_thread_info(tsk->stack);
rt_mutex_debug_task_free(tsk);
+ ftrace_retfunc_exit_task(tsk);
free_task_struct(tsk);
}
EXPORT_SYMBOL(free_task);
@@ -1269,6 +1271,7 @@
total_forks++;
spin_unlock(¤t->sighand->siglock);
write_unlock_irq(&tasklist_lock);
+ ftrace_retfunc_init_task(p);
proc_fork_connector(p);
cgroup_post_fork(p);
return p;
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index c9d7408..f77d381 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -22,7 +22,6 @@
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>
-#include <linux/ftrace.h>
#include "power.h"
@@ -257,7 +256,7 @@
int hibernation_snapshot(int platform_mode)
{
- int error, ftrace_save;
+ int error;
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
@@ -269,7 +268,6 @@
goto Close;
suspend_console();
- ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_FREEZE);
if (error)
goto Recover_platform;
@@ -299,7 +297,6 @@
Resume_devices:
device_resume(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
- __ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
platform_end(platform_mode);
@@ -370,11 +367,10 @@
int hibernation_restore(int platform_mode)
{
- int error, ftrace_save;
+ int error;
pm_prepare_console();
suspend_console();
- ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_QUIESCE);
if (error)
goto Finish;
@@ -389,7 +385,6 @@
platform_restore_cleanup(platform_mode);
device_resume(PMSG_RECOVER);
Finish:
- __ftrace_enabled_restore(ftrace_save);
resume_console();
pm_restore_console();
return error;
@@ -402,7 +397,7 @@
int hibernation_platform_enter(void)
{
- int error, ftrace_save;
+ int error;
if (!hibernation_ops)
return -ENOSYS;
@@ -417,7 +412,6 @@
goto Close;
suspend_console();
- ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
@@ -452,7 +446,6 @@
hibernation_ops->finish();
Resume_devices:
device_resume(PMSG_RESTORE);
- __ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
hibernation_ops->end();
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b8f7ce9..613f169 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -22,7 +22,6 @@
#include <linux/freezer.h>
#include <linux/vmstat.h>
#include <linux/syscalls.h>
-#include <linux/ftrace.h>
#include "power.h"
@@ -317,7 +316,7 @@
*/
int suspend_devices_and_enter(suspend_state_t state)
{
- int error, ftrace_save;
+ int error;
if (!suspend_ops)
return -ENOSYS;
@@ -328,7 +327,6 @@
goto Close;
}
suspend_console();
- ftrace_save = __ftrace_enabled_save();
suspend_test_start();
error = device_suspend(PMSG_SUSPEND);
if (error) {
@@ -360,7 +358,6 @@
suspend_test_start();
device_resume(PMSG_RESUME);
suspend_test_finish("resume devices");
- __ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
if (suspend_ops->end)
diff --git a/kernel/sched.c b/kernel/sched.c
index 4de5610..388d9db 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5901,6 +5901,7 @@
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
+ ftrace_retfunc_init_task(idle);
}
/*
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 61e8cca..9cbf776 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -3,6 +3,9 @@
# select HAVE_FUNCTION_TRACER:
#
+config USER_STACKTRACE_SUPPORT
+ bool
+
config NOP_TRACER
bool
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f212da4..53042f1 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1498,10 +1498,77 @@
#ifdef CONFIG_FUNCTION_RET_TRACER
+static atomic_t ftrace_retfunc_active;
+
/* The callback that hooks the return of a function */
trace_function_return_t ftrace_function_return =
(trace_function_return_t)ftrace_stub;
+
+/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
+static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
+{
+ int i;
+ int ret = 0;
+ unsigned long flags;
+ int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
+ struct task_struct *g, *t;
+
+ for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
+ ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
+ * sizeof(struct ftrace_ret_stack),
+ GFP_KERNEL);
+ if (!ret_stack_list[i]) {
+ start = 0;
+ end = i;
+ ret = -ENOMEM;
+ goto free;
+ }
+ }
+
+ read_lock_irqsave(&tasklist_lock, flags);
+ do_each_thread(g, t) {
+ if (start == end) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+
+ if (t->ret_stack == NULL) {
+ t->ret_stack = ret_stack_list[start++];
+ t->curr_ret_stack = -1;
+ atomic_set(&t->trace_overrun, 0);
+ }
+ } while_each_thread(g, t);
+
+unlock:
+ read_unlock_irqrestore(&tasklist_lock, flags);
+free:
+ for (i = start; i < end; i++)
+ kfree(ret_stack_list[i]);
+ return ret;
+}
+
+/* Allocate a return stack for each task */
+static int start_return_tracing(void)
+{
+ struct ftrace_ret_stack **ret_stack_list;
+ int ret;
+
+ ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
+ sizeof(struct ftrace_ret_stack *),
+ GFP_KERNEL);
+
+ if (!ret_stack_list)
+ return -ENOMEM;
+
+ do {
+ ret = alloc_retstack_tasklist(ret_stack_list);
+ } while (ret == -EAGAIN);
+
+ kfree(ret_stack_list);
+ return ret;
+}
+
int register_ftrace_return(trace_function_return_t func)
{
int ret = 0;
@@ -1516,7 +1583,12 @@
ret = -EBUSY;
goto out;
}
-
+ atomic_inc(&ftrace_retfunc_active);
+ ret = start_return_tracing();
+ if (ret) {
+ atomic_dec(&ftrace_retfunc_active);
+ goto out;
+ }
ftrace_tracing_type = FTRACE_TYPE_RETURN;
ftrace_function_return = func;
ftrace_startup();
@@ -1530,6 +1602,7 @@
{
mutex_lock(&ftrace_sysctl_lock);
+ atomic_dec(&ftrace_retfunc_active);
ftrace_function_return = (trace_function_return_t)ftrace_stub;
ftrace_shutdown();
/* Restore normal tracing type */
@@ -1537,6 +1610,32 @@
mutex_unlock(&ftrace_sysctl_lock);
}
+
+/* Allocate a return stack for newly created task */
+void ftrace_retfunc_init_task(struct task_struct *t)
+{
+ if (atomic_read(&ftrace_retfunc_active)) {
+ t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+ * sizeof(struct ftrace_ret_stack),
+ GFP_KERNEL);
+ if (!t->ret_stack)
+ return;
+ t->curr_ret_stack = -1;
+ atomic_set(&t->trace_overrun, 0);
+ } else
+ t->ret_stack = NULL;
+}
+
+void ftrace_retfunc_exit_task(struct task_struct *t)
+{
+ struct ftrace_ret_stack *ret_stack = t->ret_stack;
+
+ t->ret_stack = NULL;
+ /* NULL must become visible to IRQs before we free it: */
+ barrier();
+
+ kfree(ret_stack);
+}
#endif
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 85ced14..e206951 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -18,8 +18,46 @@
#include "trace.h"
-/* Global flag to disable all recording to ring buffers */
-static int ring_buffers_off __read_mostly;
+/*
+ * A fast way to enable or disable all ring buffers is to
+ * call tracing_on or tracing_off. Turning off the ring buffers
+ * prevents all ring buffers from being recorded to.
+ * Turning this switch on, makes it OK to write to the
+ * ring buffer, if the ring buffer is enabled itself.
+ *
+ * There's three layers that must be on in order to write
+ * to the ring buffer.
+ *
+ * 1) This global flag must be set.
+ * 2) The ring buffer must be enabled for recording.
+ * 3) The per cpu buffer must be enabled for recording.
+ *
+ * In case of an anomaly, this global flag has a bit set that
+ * will permantly disable all ring buffers.
+ */
+
+/*
+ * Global flag to disable all recording to ring buffers
+ * This has two bits: ON, DISABLED
+ *
+ * ON DISABLED
+ * ---- ----------
+ * 0 0 : ring buffers are off
+ * 1 0 : ring buffers are on
+ * X 1 : ring buffers are permanently disabled
+ */
+
+enum {
+ RB_BUFFERS_ON_BIT = 0,
+ RB_BUFFERS_DISABLED_BIT = 1,
+};
+
+enum {
+ RB_BUFFERS_ON = 1 << RB_BUFFERS_ON_BIT,
+ RB_BUFFERS_DISABLED = 1 << RB_BUFFERS_DISABLED_BIT,
+};
+
+static long ring_buffer_flags __read_mostly = RB_BUFFERS_ON;
/**
* tracing_on - enable all tracing buffers
@@ -29,7 +67,7 @@
*/
void tracing_on(void)
{
- ring_buffers_off = 0;
+ set_bit(RB_BUFFERS_ON_BIT, &ring_buffer_flags);
}
/**
@@ -42,7 +80,18 @@
*/
void tracing_off(void)
{
- ring_buffers_off = 1;
+ clear_bit(RB_BUFFERS_ON_BIT, &ring_buffer_flags);
+}
+
+/**
+ * tracing_off_permanent - permanently disable ring buffers
+ *
+ * This function, once called, will disable all ring buffers
+ * permanenty.
+ */
+void tracing_off_permanent(void)
+{
+ set_bit(RB_BUFFERS_DISABLED_BIT, &ring_buffer_flags);
}
#include "trace.h"
@@ -1185,7 +1234,7 @@
struct ring_buffer_event *event;
int cpu, resched;
- if (ring_buffers_off)
+ if (ring_buffer_flags != RB_BUFFERS_ON)
return NULL;
if (atomic_read(&buffer->record_disabled))
@@ -1297,7 +1346,7 @@
int ret = -EBUSY;
int cpu, resched;
- if (ring_buffers_off)
+ if (ring_buffer_flags != RB_BUFFERS_ON)
return -EBUSY;
if (atomic_read(&buffer->record_disabled))
@@ -2178,12 +2227,14 @@
rb_simple_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
- int *p = filp->private_data;
+ long *p = filp->private_data;
char buf[64];
int r;
- /* !ring_buffers_off == tracing_on */
- r = sprintf(buf, "%d\n", !*p);
+ if (test_bit(RB_BUFFERS_DISABLED_BIT, p))
+ r = sprintf(buf, "permanently disabled\n");
+ else
+ r = sprintf(buf, "%d\n", test_bit(RB_BUFFERS_ON_BIT, p));
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
@@ -2192,7 +2243,7 @@
rb_simple_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
- int *p = filp->private_data;
+ long *p = filp->private_data;
char buf[64];
long val;
int ret;
@@ -2209,8 +2260,10 @@
if (ret < 0)
return ret;
- /* !ring_buffers_off == tracing_on */
- *p = !val;
+ if (val)
+ set_bit(RB_BUFFERS_ON_BIT, p);
+ else
+ clear_bit(RB_BUFFERS_ON_BIT, p);
(*ppos)++;
@@ -2232,7 +2285,7 @@
d_tracer = tracing_init_dentry();
entry = debugfs_create_file("tracing_on", 0644, d_tracer,
- &ring_buffers_off, &rb_simple_fops);
+ &ring_buffer_flags, &rb_simple_fops);
if (!entry)
pr_warning("Could not create debugfs 'tracing_on' entry\n");
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4ee6f037..a45b59e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -30,6 +30,7 @@
#include <linux/gfp.h>
#include <linux/fs.h>
#include <linux/kprobes.h>
+#include <linux/seq_file.h>
#include <linux/writeback.h>
#include <linux/stacktrace.h>
@@ -275,6 +276,8 @@
"ftrace_preempt",
"branch",
"annotate",
+ "userstacktrace",
+ "sym-userobj",
NULL
};
@@ -421,6 +424,28 @@
return trace_seq_putmem(s, hex, j);
}
+static int
+trace_seq_path(struct trace_seq *s, struct path *path)
+{
+ unsigned char *p;
+
+ if (s->len >= (PAGE_SIZE - 1))
+ return 0;
+ p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
+ if (!IS_ERR(p)) {
+ p = mangle_path(s->buffer + s->len, p, "\n");
+ if (p) {
+ s->len = p - s->buffer;
+ return 1;
+ }
+ } else {
+ s->buffer[s->len++] = '?';
+ return 1;
+ }
+
+ return 0;
+}
+
static void
trace_seq_reset(struct trace_seq *s)
{
@@ -661,6 +686,21 @@
static DEFINE_SPINLOCK(tracing_start_lock);
/**
+ * ftrace_off_permanent - disable all ftrace code permanently
+ *
+ * This should only be called when a serious anomally has
+ * been detected. This will turn off the function tracing,
+ * ring buffers, and other tracing utilites. It takes no
+ * locks and can be called from any context.
+ */
+void ftrace_off_permanent(void)
+{
+ tracing_disabled = 1;
+ ftrace_stop();
+ tracing_off_permanent();
+}
+
+/**
* tracing_start - quick start of the tracer
*
* If tracing is enabled but was stopped by tracing_stop,
@@ -801,6 +841,7 @@
entry->preempt_count = pc & 0xff;
entry->pid = (tsk) ? tsk->pid : 0;
+ entry->tgid = (tsk) ? tsk->tgid : 0;
entry->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
@@ -918,6 +959,44 @@
ftrace_trace_stack(tr, data, flags, skip, preempt_count());
}
+static void ftrace_trace_userstack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags, int pc)
+{
+ struct ring_buffer_event *event;
+ struct userstack_entry *entry;
+ struct stack_trace trace;
+ unsigned long irq_flags;
+
+ if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
+ return;
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_USER_STACK;
+
+ memset(&entry->caller, 0, sizeof(entry->caller));
+
+ trace.nr_entries = 0;
+ trace.max_entries = FTRACE_STACK_ENTRIES;
+ trace.skip = 0;
+ trace.entries = entry->caller;
+
+ save_stack_trace_user(&trace);
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+}
+
+void __trace_userstack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags)
+{
+ ftrace_trace_userstack(tr, data, flags, preempt_count());
+}
+
static void
ftrace_trace_special(void *__tr, void *__data,
unsigned long arg1, unsigned long arg2, unsigned long arg3,
@@ -941,6 +1020,7 @@
entry->arg3 = arg3;
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
ftrace_trace_stack(tr, data, irq_flags, 4, pc);
+ ftrace_trace_userstack(tr, data, irq_flags, pc);
trace_wake_up();
}
@@ -979,6 +1059,7 @@
entry->next_cpu = task_cpu(next);
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
ftrace_trace_stack(tr, data, flags, 5, pc);
+ ftrace_trace_userstack(tr, data, flags, pc);
}
void
@@ -1008,6 +1089,7 @@
entry->next_cpu = task_cpu(wakee);
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
ftrace_trace_stack(tr, data, flags, 6, pc);
+ ftrace_trace_userstack(tr, data, flags, pc);
trace_wake_up();
}
@@ -1387,6 +1469,78 @@
return ret;
}
+static inline int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
+ unsigned long ip, unsigned long sym_flags)
+{
+ struct file *file = NULL;
+ unsigned long vmstart = 0;
+ int ret = 1;
+
+ if (mm) {
+ const struct vm_area_struct *vma;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, ip);
+ if (vma) {
+ file = vma->vm_file;
+ vmstart = vma->vm_start;
+ }
+ if (file) {
+ ret = trace_seq_path(s, &file->f_path);
+ if (ret)
+ ret = trace_seq_printf(s, "[+0x%lx]", ip - vmstart);
+ }
+ up_read(&mm->mmap_sem);
+ }
+ if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
+ ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+ return ret;
+}
+
+static int
+seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
+ unsigned long sym_flags)
+{
+ struct mm_struct *mm = NULL;
+ int ret = 1;
+ unsigned int i;
+
+ if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
+ struct task_struct *task;
+ /*
+ * we do the lookup on the thread group leader,
+ * since individual threads might have already quit!
+ */
+ rcu_read_lock();
+ task = find_task_by_vpid(entry->ent.tgid);
+ if (task)
+ mm = get_task_mm(task);
+ rcu_read_unlock();
+ }
+
+ for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+ unsigned long ip = entry->caller[i];
+
+ if (ip == ULONG_MAX || !ret)
+ break;
+ if (i && ret)
+ ret = trace_seq_puts(s, " <- ");
+ if (!ip) {
+ if (ret)
+ ret = trace_seq_puts(s, "??");
+ continue;
+ }
+ if (!ret)
+ break;
+ if (ret)
+ ret = seq_print_user_ip(s, mm, ip, sym_flags);
+ }
+
+ if (mm)
+ mmput(mm);
+ return ret;
+}
+
static void print_lat_help_header(struct seq_file *m)
{
seq_puts(m, "# _------=> CPU# \n");
@@ -1702,6 +1856,15 @@
field->line);
break;
}
+ case TRACE_USER_STACK: {
+ struct userstack_entry *field;
+
+ trace_assign_type(field, entry);
+
+ seq_print_userip_objs(field, s, sym_flags);
+ trace_seq_putc(s, '\n');
+ break;
+ }
default:
trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
@@ -1853,6 +2016,19 @@
field->line);
break;
}
+ case TRACE_USER_STACK: {
+ struct userstack_entry *field;
+
+ trace_assign_type(field, entry);
+
+ ret = seq_print_userip_objs(field, s, sym_flags);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ ret = trace_seq_putc(s, '\n');
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ break;
+ }
}
return TRACE_TYPE_HANDLED;
}
@@ -1912,6 +2088,7 @@
break;
}
case TRACE_SPECIAL:
+ case TRACE_USER_STACK:
case TRACE_STACK: {
struct special_entry *field;
@@ -2000,6 +2177,7 @@
break;
}
case TRACE_SPECIAL:
+ case TRACE_USER_STACK:
case TRACE_STACK: {
struct special_entry *field;
@@ -2054,6 +2232,7 @@
break;
}
case TRACE_SPECIAL:
+ case TRACE_USER_STACK:
case TRACE_STACK: {
struct special_entry *field;
@@ -3488,6 +3667,9 @@
atomic_inc(&global_trace.data[cpu]->disabled);
}
+ /* don't look at user memory in panic mode */
+ trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
+
printk(KERN_TRACE "Dumping ftrace buffer:\n");
iter.tr = &global_trace;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2cb12fd..28c15c2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -26,6 +26,7 @@
TRACE_BOOT_CALL,
TRACE_BOOT_RET,
TRACE_FN_RET,
+ TRACE_USER_STACK,
__TRACE_LAST_TYPE
};
@@ -42,6 +43,7 @@
unsigned char flags;
unsigned char preempt_count;
int pid;
+ int tgid;
};
/*
@@ -99,6 +101,11 @@
unsigned long caller[FTRACE_STACK_ENTRIES];
};
+struct userstack_entry {
+ struct trace_entry ent;
+ unsigned long caller[FTRACE_STACK_ENTRIES];
+};
+
/*
* ftrace_printk entry:
*/
@@ -240,6 +247,7 @@
IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
+ IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
IF_ASSIGN(var, ent, struct special_entry, 0); \
IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
@@ -500,6 +508,8 @@
TRACE_ITER_PREEMPTONLY = 0x800,
TRACE_ITER_BRANCH = 0x1000,
TRACE_ITER_ANNOTATE = 0x2000,
+ TRACE_ITER_USERSTACKTRACE = 0x4000,
+ TRACE_ITER_SYM_USEROBJ = 0x8000
};
/*
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 433d650..2a98a20 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -18,12 +18,14 @@
static struct trace_array *mmio_trace_array;
static bool overrun_detected;
+static unsigned long prev_overruns;
static void mmio_reset_data(struct trace_array *tr)
{
int cpu;
overrun_detected = false;
+ prev_overruns = 0;
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
@@ -123,16 +125,12 @@
static unsigned long count_overruns(struct trace_iterator *iter)
{
- int cpu;
unsigned long cnt = 0;
-/* FIXME: */
-#if 0
- for_each_online_cpu(cpu) {
- cnt += iter->overrun[cpu];
- iter->overrun[cpu] = 0;
- }
-#endif
- (void)cpu;
+ unsigned long over = ring_buffer_overruns(iter->tr->buffer);
+
+ if (over > prev_overruns)
+ cnt = over - prev_overruns;
+ prev_overruns = over;
return cnt;
}
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index eeac71c..0197e2f 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -130,11 +130,13 @@
my %convert; # List of local functions used that needs conversion
my $type;
+my $nm_regex; # Find the local functions (return function)
my $section_regex; # Find the start of a section
my $function_regex; # Find the name of a function
# (return offset and func name)
my $mcount_regex; # Find the call site to mcount (return offset)
-my $alignment; # The .align value to use for $mcount_section
+my $alignment; # The .align value to use for $mcount_section
+my $section_type; # Section header plus possible alignment command
if ($arch eq "x86") {
if ($bits == 64) {
@@ -144,9 +146,18 @@
}
}
+#
+# We base the defaults off of i386, the other archs may
+# feel free to change them in the below if statements.
+#
+$nm_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\S+)";
+$section_regex = "Disassembly of section\\s+(\\S+):";
+$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
+$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
+$section_type = '@progbits';
+$type = ".long";
+
if ($arch eq "x86_64") {
- $section_regex = "Disassembly of section\\s+(\\S+):";
- $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
$type = ".quad";
$alignment = 8;
@@ -158,10 +169,6 @@
$cc .= " -m64";
} elsif ($arch eq "i386") {
- $section_regex = "Disassembly of section\\s+(\\S+):";
- $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
- $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
- $type = ".long";
$alignment = 4;
# force flags for this arch
@@ -170,6 +177,27 @@
$objcopy .= " -O elf32-i386";
$cc .= " -m32";
+} elsif ($arch eq "sh") {
+ $alignment = 2;
+
+ # force flags for this arch
+ $ld .= " -m shlelf_linux";
+ $objcopy .= " -O elf32-sh-linux";
+ $cc .= " -m32";
+
+} elsif ($arch eq "powerpc") {
+ $nm_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)";
+ $function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?.*?)>:";
+ $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$";
+
+ if ($bits == 64) {
+ $type = ".quad";
+ }
+
+} elsif ($arch eq "arm") {
+ $alignment = 2;
+ $section_type = '%progbits';
+
} else {
die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD";
}
@@ -239,7 +267,7 @@
#
open (IN, "$nm $inputfile|") || die "error running $nm";
while (<IN>) {
- if (/^[0-9a-fA-F]+\s+t\s+(\S+)/) {
+ if (/$nm_regex/) {
$locals{$1} = 1;
} elsif (/^[0-9a-fA-F]+\s+([wW])\s+(\S+)/) {
$weak{$2} = $1;
@@ -290,8 +318,8 @@
if (!$opened) {
open(FILE, ">$mcount_s") || die "can't create $mcount_s\n";
$opened = 1;
- print FILE "\t.section $mcount_section,\"a\",\@progbits\n";
- print FILE "\t.align $alignment\n";
+ print FILE "\t.section $mcount_section,\"a\",$section_type\n";
+ print FILE "\t.align $alignment\n" if (defined($alignment));
}
printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset;
}