Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  kprobes/x86: Fix the return address of multiple kretprobes
  perf tools: Fix build error on read only source.
  perf, x86: Fix Intel-nhm PMU programming errata workaround

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 214ac860ebe0d26df806999f880633919d1ad816..d8d86d01400866c6320001fb715301276747cd52 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -491,33 +491,78 @@ static void intel_pmu_enable_all(int added)
  *   Intel Errata AAP53  (model 30)
  *   Intel Errata BD53   (model 44)
  *
- * These chips need to be 'reset' when adding counters by programming
- * the magic three (non counting) events 0x4300D2, 0x4300B1 and 0x4300B5
- * either in sequence on the same PMC or on different PMCs.
+ * The official story:
+ *   These chips need to be 'reset' when adding counters by programming the
+ *   magic three (non-counting) events 0x4300B5, 0x4300D2, and 0x4300B1 either
+ *   in sequence on the same PMC or on different PMCs.
+ *
+ * In practise it appears some of these events do in fact count, and
+ * we need to programm all 4 events.
  */
-static void intel_pmu_nhm_enable_all(int added)
+static void intel_pmu_nhm_workaround(void)
 {
-       if (added) {
-               struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-               int i;
+       struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+       static const unsigned long nhm_magic[4] = {
+               0x4300B5,
+               0x4300D2,
+               0x4300B1,
+               0x4300B1
+       };
+       struct perf_event *event;
+       int i;
+
+       /*
+        * The Errata requires below steps:
+        * 1) Clear MSR_IA32_PEBS_ENABLE and MSR_CORE_PERF_GLOBAL_CTRL;
+        * 2) Configure 4 PERFEVTSELx with the magic events and clear
+        *    the corresponding PMCx;
+        * 3) set bit0~bit3 of MSR_CORE_PERF_GLOBAL_CTRL;
+        * 4) Clear MSR_CORE_PERF_GLOBAL_CTRL;
+        * 5) Clear 4 pairs of ERFEVTSELx and PMCx;
+        */
+
+       /*
+        * The real steps we choose are a little different from above.
+        * A) To reduce MSR operations, we don't run step 1) as they
+        *    are already cleared before this function is called;
+        * B) Call x86_perf_event_update to save PMCx before configuring
+        *    PERFEVTSELx with magic number;
+        * C) With step 5), we do clear only when the PERFEVTSELx is
+        *    not used currently.
+        * D) Call x86_perf_event_set_period to restore PMCx;
+        */
 
-               wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + 0, 0x4300D2);
-               wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + 1, 0x4300B1);
-               wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + 2, 0x4300B5);
+       /* We always operate 4 pairs of PERF Counters */
+       for (i = 0; i < 4; i++) {
+               event = cpuc->events[i];
+               if (event)
+                       x86_perf_event_update(event);
+       }
 
-               wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0x3);
-               wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0x0);
+       for (i = 0; i < 4; i++) {
+               wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + i, nhm_magic[i]);
+               wrmsrl(MSR_ARCH_PERFMON_PERFCTR0 + i, 0x0);
+       }
 
-               for (i = 0; i < 3; i++) {
-                       struct perf_event *event = cpuc->events[i];
+       wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0xf);
+       wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0x0);
 
-                       if (!event)
-                               continue;
+       for (i = 0; i < 4; i++) {
+               event = cpuc->events[i];
 
+               if (event) {
+                       x86_perf_event_set_period(event);
                        __x86_pmu_enable_event(&event->hw,
-                                              ARCH_PERFMON_EVENTSEL_ENABLE);
-               }
+                                       ARCH_PERFMON_EVENTSEL_ENABLE);
+               } else
+                       wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + i, 0x0);
        }
+}
+
+static void intel_pmu_nhm_enable_all(int added)
+{
+       if (added)
+               intel_pmu_nhm_workaround();
        intel_pmu_enable_all(added);
 }
 

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 1bfb6cf4dd55d67aeeebbbf89d0bb60283a94c94..770ebfb349e93efe3367cf0c6caff93b61b8b884 100644 (file)
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -709,6 +709,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
        struct hlist_node *node, *tmp;
        unsigned long flags, orig_ret_address = 0;
        unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
+       kprobe_opcode_t *correct_ret_addr = NULL;
 
        INIT_HLIST_HEAD(&empty_rp);
        kretprobe_hash_lock(current, &head, &flags);
@@ -740,14 +741,34 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
                        /* another task is sharing our hash bucket */
                        continue;
 
+               orig_ret_address = (unsigned long)ri->ret_addr;
+
+               if (orig_ret_address != trampoline_address)
+                       /*
+                        * This is the real return address. Any other
+                        * instances associated with this task are for
+                        * other calls deeper on the call stack
+                        */
+                       break;
+       }
+
+       kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
+       correct_ret_addr = ri->ret_addr;
+       hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+               if (ri->task != current)
+                       /* another task is sharing our hash bucket */
+                       continue;
+
+               orig_ret_address = (unsigned long)ri->ret_addr;
                if (ri->rp && ri->rp->handler) {
                        __get_cpu_var(current_kprobe) = &ri->rp->kp;
                        get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
+                       ri->ret_addr = correct_ret_addr;
                        ri->rp->handler(ri, regs);
                        __get_cpu_var(current_kprobe) = NULL;
                }
 
-               orig_ret_address = (unsigned long)ri->ret_addr;
                recycle_rp_inst(ri, &empty_rp);
 
                if (orig_ret_address != trampoline_address)
@@ -759,8 +780,6 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
                        break;
        }
 
-       kretprobe_assert(ri, orig_ret_address, trampoline_address);
-
        kretprobe_hash_unlock(current, &flags);
 
        hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index dcb9700b88d2ec86c456c1185e99cf8b4619dfe4..4f1fa77c1feb0b7a854ab8a85bd21682cbc66377 100644 (file)
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -5,6 +5,12 @@ endif
 # The default target of this Makefile is...
 all::
 
+ifneq ($(OUTPUT),)
+# check that the output directory actually exists
+OUTDIR := $(shell cd $(OUTPUT) && /bin/pwd)
+$(if $(OUTDIR),, $(error output directory "$(OUTPUT)" does not exist))
+endif
+
 # Define V=1 to have a more verbose compile.
 # Define V=2 to have an even more verbose compile.
 #
@@ -931,15 +937,15 @@ $(OUTPUT)common-cmds.h: $(wildcard Documentation/perf-*.txt)
        $(QUIET_GEN). util/generate-cmdlist.sh > $@+ && mv $@+ $@
 
 $(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
-       $(QUIET_GEN)$(RM) $@ $@+ && \
+       $(QUIET_GEN)$(RM) $(OUTPUT)$@ $(OUTPUT)$@+ && \
        sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
            -e 's|@SHELL_PATH@|$(SHELL_PATH_SQ)|' \
            -e 's|@@PERL@@|$(PERL_PATH_SQ)|g' \
            -e 's/@@PERF_VERSION@@/$(PERF_VERSION)/g' \
            -e 's/@@NO_CURL@@/$(NO_CURL)/g' \
-           $@.sh >$@+ && \
-       chmod +x $@+ && \
-       mv $@+ $(OUTPUT)$@
+           $@.sh > $(OUTPUT)$@+ && \
+       chmod +x $(OUTPUT)$@+ && \
+       mv $(OUTPUT)$@+ $(OUTPUT)$@
 
 configure: configure.ac
        $(QUIET_GEN)$(RM) $@ $<+ && \

diff --git a/tools/perf/feature-tests.mak b/tools/perf/feature-tests.mak
index ddb68e601f0ec2f67558afef92d3506f7661cd82..7a7b6085905382c791834b0c0f35ed5f39658e26 100644 (file)
--- a/tools/perf/feature-tests.mak
+++ b/tools/perf/feature-tests.mak
@@ -113,7 +113,7 @@ endef
 # try-cc
 # Usage: option = $(call try-cc, source-to-build, cc-options)
 try-cc = $(shell sh -c                                           \
-       'TMP="$(TMPOUT).$$$$";                                    \
+       'TMP="$(OUTPUT)$(TMPOUT).$$$$";                           \
         echo "$(1)" |                                            \
         $(CC) -x c - $(2) -o "$$TMP" > /dev/null 2>&1 && echo y; \
         rm -f "$$TMP"')