Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
  tracing, net: fix net tree and tracing tree merge interaction
  tracing, powerpc: fix powerpc tree and tracing tree interaction
  ring-buffer: do not remove reader page from list on ring buffer free
  function-graph: allow unregistering twice
  trace: make argument 'mem' of trace_seq_putmem() const
  tracing: add missing 'extern' keywords to trace_output.h
  tracing: provide trace_seq_reserve()
  blktrace: print out BLK_TN_MESSAGE properly
  blktrace: extract duplidate code
  blktrace: fix memory leak when freeing struct blk_io_trace
  blktrace: fix blk_probes_ref chaos
  blktrace: make classic output more classic
  blktrace: fix off-by-one bug
  blktrace: fix the original blktrace
  blktrace: fix a race when creating blk_tree_root in debugfs
  blktrace: fix timestamp in binary output
  tracing, Text Edit Lock: cleanup
  tracing: filter fix for TRACE_EVENT_FORMAT events
  ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
  x86: kretprobe-booster interrupt emulation code fix
  ...

Fix up trivial conflicts in
 arch/parisc/include/asm/ftrace.h
 include/linux/memory.h
 kernel/extable.c
 kernel/module.c

8 files changed, 180 insertions, 83 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index c611ad64137..145cce75cda 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -66,7 +66,8 @@ obj-$(CONFIG_X86_MPPARSE)	+= mpparse.o
 obj-y                           += apic/
 obj-$(CONFIG_X86_REBOOTFIXUPS)  += reboot_fixups_32.o
 obj-$(CONFIG_DYNAMIC_FTRACE)    += ftrace.o
-obj-$(CONFIG_FUNCTION_GRAPH_TRACER)     += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
+obj-$(CONFIG_FTRACE_SYSCALLS)   += ftrace.o
 obj-$(CONFIG_KEXEC)             += machine_kexec_$(BITS).o
 obj-$(CONFIG_KEXEC)             += relocate_kernel_$(BITS).o crash.o
 obj-$(CONFIG_CRASH_DUMP)        += crash_dump_$(BITS).o
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 4c80f155743..f5765870257 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -5,6 +5,7 @@
 #include <linux/kprobes.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
+#include <linux/memory.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
@@ -12,7 +13,9 @@
 #include <asm/nmi.h>
 #include <asm/vsyscall.h>
 #include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
 #include <asm/io.h>
+#include <asm/fixmap.h>
 
 #define MAX_PATCH_LEN (255-1)
 
@@ -226,6 +229,7 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
 {
         u8 **ptr;
 
+        mutex_lock(&text_mutex);
         for (ptr = start; ptr < end; ptr++) {
                 if (*ptr < text)
                         continue;
@@ -234,6 +238,7 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
                 /* turn DS segment override prefix into lock prefix */
                 text_poke(*ptr, ((unsigned char []){0xf0}), 1);
         };
+        mutex_unlock(&text_mutex);
 }
 
 static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end)
@@ -243,6 +248,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
         if (noreplace_smp)
                 return;
 
+        mutex_lock(&text_mutex);
         for (ptr = start; ptr < end; ptr++) {
                 if (*ptr < text)
                         continue;
@@ -251,6 +257,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
                 /* turn lock prefix into DS segment override prefix */
                 text_poke(*ptr, ((unsigned char []){0x3E}), 1);
         };
+        mutex_unlock(&text_mutex);
 }
 
 struct smp_alt_module {
@@ -500,15 +507,16 @@ void *text_poke_early(void *addr, const void *opcode, size_t len)
  * It means the size must be writable atomically and the address must be aligned
  * in a way that permits an atomic write. It also makes sure we fit on a single
  * page.
+ *
+ * Note: Must be called under text_mutex.
  */
 void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
 {
+        unsigned long flags;
         char *vaddr;
-        int nr_pages = 2;
         struct page *pages[2];
         int i;
 
-        might_sleep();
         if (!core_kernel_text((unsigned long)addr)) {
                 pages[0] = vmalloc_to_page(addr);
                 pages[1] = vmalloc_to_page(addr + PAGE_SIZE);
@@ -518,18 +526,21 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
                 pages[1] = virt_to_page(addr + PAGE_SIZE);
         }
         BUG_ON(!pages[0]);
-        if (!pages[1])
-                nr_pages = 1;
-        vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
-        BUG_ON(!vaddr);
-        local_irq_disable();
+        local_irq_save(flags);
+        set_fixmap(FIX_TEXT_POKE0, page_to_phys(pages[0]));
+        if (pages[1])
+                set_fixmap(FIX_TEXT_POKE1, page_to_phys(pages[1]));
+        vaddr = (char *)fix_to_virt(FIX_TEXT_POKE0);
         memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len);
-        local_irq_enable();
-        vunmap(vaddr);
+        clear_fixmap(FIX_TEXT_POKE0);
+        if (pages[1])
+                clear_fixmap(FIX_TEXT_POKE1);
+        local_flush_tlb();
         sync_core();
         /* Could also do a CLFLUSH here to speed up CPU recovery; but
            that causes hangs on some VIA CPUs. */
         for (i = 0; i < len; i++)
                 BUG_ON(((char *)addr)[i] != ((char *)opcode)[i]);
+        local_irq_restore(flags);
         return addr;
 }
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 23da96e57b1..05209b5cc6c 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -33,7 +33,7 @@
 #include <linux/cpufreq.h>
 #include <linux/compiler.h>
 #include <linux/dmi.h>
-#include <linux/ftrace.h>
+#include <trace/power.h>
 
 #include <linux/acpi.h>
 #include <linux/io.h>
@@ -72,6 +72,8 @@ struct acpi_cpufreq_data {
 
 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
 
+DEFINE_TRACE(power_mark);
+
 /* acpi_perf_data is a pointer to percpu data. */
 static struct acpi_processor_performance *acpi_perf_data;
 
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index dd2130b0fb3..95ea5fa7d44 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -15,6 +15,7 @@
 #include <linux/bug.h>
 #include <linux/nmi.h>
 #include <linux/sysfs.h>
+#include <linux/ftrace.h>
 
 #include <asm/stacktrace.h>
 
@@ -196,6 +197,11 @@ unsigned __kprobes long oops_begin(void)
         int cpu;
         unsigned long flags;
 
+        /* notify the hw-branch tracer so it may disable tracing and
+           add the last trace to the trace buffer -
+           the earlier this happens, the more useful the trace. */
+        trace_hw_branch_oops();
+
         oops_enter();
 
         /* racy, but better than risking deadlock. */
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 76f7141e0f9..61df7753212 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/list.h>
 
+#include <asm/cacheflush.h>
 #include <asm/ftrace.h>
 #include <linux/ftrace.h>
 #include <asm/nops.h>
@@ -26,6 +27,18 @@
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+int ftrace_arch_code_modify_prepare(void)
+{
+        set_kernel_text_rw();
+        return 0;
+}
+
+int ftrace_arch_code_modify_post_process(void)
+{
+        set_kernel_text_ro();
+        return 0;
+}
+
 union ftrace_code_union {
         char code[MCOUNT_INSN_SIZE];
         struct {
@@ -66,11 +79,11 @@ static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
  *
  * 1) Put the instruction pointer into the IP buffer
  *    and the new code into the "code" buffer.
- * 2) Set a flag that says we are modifying code
- * 3) Wait for any running NMIs to finish.
- * 4) Write the code
- * 5) clear the flag.
- * 6) Wait for any running NMIs to finish.
+ * 2) Wait for any running NMIs to finish and set a flag that says
+ *    we are modifying code, it is done in an atomic operation.
+ * 3) Write the code
+ * 4) clear the flag.
+ * 5) Wait for any running NMIs to finish.
  *
  * If an NMI is executed, the first thing it does is to call
  * "ftrace_nmi_enter". This will check if the flag is set to write
@@ -82,9 +95,9 @@ static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
  * are the same as what exists.
  */
 
-static atomic_t in_nmi = ATOMIC_INIT(0);
+#define MOD_CODE_WRITE_FLAG (1 << 31)   /* set when NMI should do the write */
+static atomic_t nmi_running = ATOMIC_INIT(0);
 static int mod_code_status;             /* holds return value of text write */
-static int mod_code_write;              /* set when NMI should do the write */
 static void *mod_code_ip;               /* holds the IP to write to */
 static void *mod_code_newcode;          /* holds the text to write to the IP */
 
@@ -101,6 +114,20 @@ int ftrace_arch_read_dyn_info(char *buf, int size)
         return r;
 }
 
+static void clear_mod_flag(void)
+{
+        int old = atomic_read(&nmi_running);
+
+        for (;;) {
+                int new = old & ~MOD_CODE_WRITE_FLAG;
+
+                if (old == new)
+                        break;
+
+                old = atomic_cmpxchg(&nmi_running, old, new);
+        }
+}
+
 static void ftrace_mod_code(void)
 {
         /*
@@ -111,37 +138,52 @@ static void ftrace_mod_code(void)
          */
         mod_code_status = probe_kernel_write(mod_code_ip, mod_code_newcode,
                                              MCOUNT_INSN_SIZE);
+
+        /* if we fail, then kill any new writers */
+        if (mod_code_status)
+                clear_mod_flag();
 }
 
 void ftrace_nmi_enter(void)
 {
-        atomic_inc(&in_nmi);
-        /* Must have in_nmi seen before reading write flag */
-        smp_mb();
-        if (mod_code_write) {
+        if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {
+                smp_rmb();
                 ftrace_mod_code();
                 atomic_inc(&nmi_update_count);
         }
+        /* Must have previous changes seen before executions */
+        smp_mb();
 }
 
 void ftrace_nmi_exit(void)
 {
-        /* Finish all executions before clearing in_nmi */
-        smp_wmb();
-        atomic_dec(&in_nmi);
+        /* Finish all executions before clearing nmi_running */
+        smp_mb();
+        atomic_dec(&nmi_running);
+}
+
+static void wait_for_nmi_and_set_mod_flag(void)
+{
+        if (!atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG))
+                return;
+
+        do {
+                cpu_relax();
+        } while (atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG));
+
+        nmi_wait_count++;
 }
 
 static void wait_for_nmi(void)
 {
-        int waited = 0;
+        if (!atomic_read(&nmi_running))
+                return;
 
-        while (atomic_read(&in_nmi)) {
-                waited = 1;
+        do {
                 cpu_relax();
-        }
+        } while (atomic_read(&nmi_running));
 
-        if (waited)
-                nmi_wait_count++;
+        nmi_wait_count++;
 }
 
 static int
@@ -151,14 +193,9 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
         mod_code_newcode = new_code;
 
         /* The buffers need to be visible before we let NMIs write them */
-        smp_wmb();
-
-        mod_code_write = 1;
-
-        /* Make sure write bit is visible before we wait on NMIs */
         smp_mb();
 
-        wait_for_nmi();
+        wait_for_nmi_and_set_mod_flag();
 
         /* Make sure all running NMIs have finished before we write the code */
         smp_mb();
@@ -166,13 +203,9 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
         ftrace_mod_code();
 
         /* Make sure the write happens before clearing the bit */
-        smp_wmb();
-
-        mod_code_write = 0;
-
-        /* make sure NMIs see the cleared bit */
         smp_mb();
 
+        clear_mod_flag();
         wait_for_nmi();
 
         return mod_code_status;
@@ -368,25 +401,6 @@ int ftrace_disable_ftrace_graph_caller(void)
         return ftrace_mod_jmp(ip, old_offset, new_offset);
 }
 
-#else /* CONFIG_DYNAMIC_FTRACE */
-
-/*
- * These functions are picked from those used on
- * this page for dynamic ftrace. They have been
- * simplified to ignore all traces in NMI context.
- */
-static atomic_t in_nmi;
-
-void ftrace_nmi_enter(void)
-{
-        atomic_inc(&in_nmi);
-}
-
-void ftrace_nmi_exit(void)
-{
-        atomic_dec(&in_nmi);
-}
-
 #endif /* !CONFIG_DYNAMIC_FTRACE */
 
 /*
@@ -396,14 +410,13 @@ void ftrace_nmi_exit(void)
 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 {
         unsigned long old;
-        unsigned long long calltime;
         int faulted;
         struct ftrace_graph_ent trace;
         unsigned long return_hooker = (unsigned long)
                                 &return_to_handler;
 
         /* Nmi's are currently unsupported */
-        if (unlikely(atomic_read(&in_nmi)))
+        if (unlikely(in_nmi()))
                 return;
 
         if (unlikely(atomic_read(&current->tracing_graph_pause)))
@@ -439,17 +452,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                 return;
         }
 
-        if (unlikely(!__kernel_text_address(old))) {
-                ftrace_graph_stop();
-                *parent = old;
-                WARN_ON(1);
-                return;
-        }
-
-        calltime = cpu_clock(raw_smp_processor_id());
-
-        if (ftrace_push_return_trace(old, calltime,
-                                self_addr, &trace.depth) == -EBUSY) {
+        if (ftrace_push_return_trace(old, self_addr, &trace.depth) == -EBUSY) {
                 *parent = old;
                 return;
         }
@@ -463,3 +466,66 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
         }
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#ifdef CONFIG_FTRACE_SYSCALLS
+
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+extern unsigned long *sys_call_table;
+
+static struct syscall_metadata **syscalls_metadata;
+
+static struct syscall_metadata *find_syscall_meta(unsigned long *syscall)
+{
+        struct syscall_metadata *start;
+        struct syscall_metadata *stop;
+        char str[KSYM_SYMBOL_LEN];
+
+
+        start = (struct syscall_metadata *)__start_syscalls_metadata;
+        stop = (struct syscall_metadata *)__stop_syscalls_metadata;
+        kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str);
+
+        for ( ; start < stop; start++) {
+                if (start->name && !strcmp(start->name, str))
+                        return start;
+        }
+        return NULL;
+}
+
+struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+        if (!syscalls_metadata || nr >= FTRACE_SYSCALL_MAX || nr < 0)
+                return NULL;
+
+        return syscalls_metadata[nr];
+}
+
+void arch_init_ftrace_syscalls(void)
+{
+        int i;
+        struct syscall_metadata *meta;
+        unsigned long **psys_syscall_table = &sys_call_table;
+        static atomic_t refs;
+
+        if (atomic_inc_return(&refs) != 1)
+                goto end;
+
+        syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
+                                        FTRACE_SYSCALL_MAX, GFP_KERNEL);
+        if (!syscalls_metadata) {
+                WARN_ON(1);
+                return;
+        }
+
+        for (i = 0; i < FTRACE_SYSCALL_MAX; i++) {
+                meta = find_syscall_meta(psys_syscall_table[i]);
+                syscalls_metadata[i] = meta;
+        }
+        return;
+
+        /* Paranoid: avoid overflow */
+end:
+        atomic_dec(&refs);
+}
+#endif
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 55b94614e34..7b5169d2b00 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -638,13 +638,13 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
 #else
                         "       pushf\n"
                         /*
-                         * Skip cs, ip, orig_ax.
+                         * Skip cs, ip, orig_ax and gs.
                          * trampoline_handler() will plug in these values
                          */
-                        "       subl $12, %esp\n"
+                        "       subl $16, %esp\n"
                         "       pushl %fs\n"
-                        "       pushl %ds\n"
                         "       pushl %es\n"
+                        "       pushl %ds\n"
                         "       pushl %eax\n"
                         "       pushl %ebp\n"
                         "       pushl %edi\n"
@@ -655,10 +655,10 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
                         "       movl %esp, %eax\n"
                         "       call trampoline_handler\n"
                         /* Move flags to cs */
-                        "       movl 52(%esp), %edx\n"
-                        "       movl %edx, 48(%esp)\n"
+                        "       movl 56(%esp), %edx\n"
+                        "       movl %edx, 52(%esp)\n"
                         /* Replace saved flags with true return address. */
-                        "       movl %eax, 52(%esp)\n"
+                        "       movl %eax, 56(%esp)\n"
                         "       popl %ebx\n"
                         "       popl %ecx\n"
                         "       popl %edx\n"
@@ -666,8 +666,8 @@ static void __used __kprobes kretprobe_trampoline_holder(void)
                         "       popl %edi\n"
                         "       popl %ebp\n"
                         "       popl %eax\n"
-                        /* Skip ip, orig_ax, es, ds, fs */
-                        "       addl $20, %esp\n"
+                        /* Skip ds, es, fs, gs, orig_ax and ip */
+                        "       addl $24, %esp\n"
                         "       popf\n"
 #endif
                         "       ret\n");
@@ -691,6 +691,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
         regs->cs = __KERNEL_CS;
 #else
         regs->cs = __KERNEL_CS | get_kernel_rpl();
+        regs->gs = 0;
 #endif
         regs->ip = trampoline_address;
         regs->orig_ax = ~0UL;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 25e28087a3e..ca989158e84 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -8,7 +8,7 @@
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/clockchips.h>
-#include <linux/ftrace.h>
+#include <trace/power.h>
 #include <asm/system.h>
 #include <asm/apic.h>
 #include <asm/idle.h>
@@ -22,6 +22,9 @@ EXPORT_SYMBOL(idle_nomwait);
 
 struct kmem_cache *task_xstate_cachep;
 
+DEFINE_TRACE(power_start);
+DEFINE_TRACE(power_end);
+
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
         *dst = *src;
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index b7cc21bc6ae..fe9345c967d 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -21,6 +21,7 @@
 #include <linux/audit.h>
 #include <linux/seccomp.h>
 #include <linux/signal.h>
+#include <linux/ftrace.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -1415,6 +1416,9 @@ asmregparm long syscall_trace_enter(struct pt_regs *regs)
             tracehook_report_syscall_entry(regs))
                 ret = -1L;
 
+        if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
+                ftrace_syscall_enter(regs);
+
         if (unlikely(current->audit_context)) {
                 if (IS_IA32)
                         audit_syscall_entry(AUDIT_ARCH_I386,
@@ -1438,6 +1442,9 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
         if (unlikely(current->audit_context))
                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
 
+        if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
+                ftrace_syscall_exit(regs);
+
         if (test_thread_flag(TIF_SYSCALL_TRACE))
                 tracehook_report_syscall_exit(regs, 0);