[GIT PULL] perf fixes

From: Ingo Molnar
Date: Sun Feb 09 2014 - 03:02:02 EST

Linus,

Please pull the latest perf-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus

# HEAD: 2737fce8bc8dea2852289df29b4f92e6a7fb7c91 Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Tooling fixes, mostly related to the KASLR fallout, but also other
fixes.

Thanks,

Ingo

------------------>
Adrian Hunter (9):
perf symbols: Fix symbol annotation for relocated kernel
perf tools: Add kallsyms__get_function_start()
perf machine: Add machine__get_kallsyms_filename()
perf machine: Set up ref_reloc_sym in machine__create_kernel_maps()
perf record: Get ref_reloc_sym from kernel map
perf symbols: Prevent the use of kcore if the kernel has moved
perf tests: No need to set up ref_reloc_sym
perf tools: Adjust kallsyms for relocated kernel
perf buildid-cache: Check relocation when checking for existing kcore

Avi Kivity (1):
perf tools: Demangle kernel and kernel module symbols too

Baruch Siach (1):
perf/doc: Remove mention of non-existent set_perf_event_pending() from design.txt

Francesco Fusco (1):
perf tools: Fix include for non x86 architectures

Peter Zijlstra (1):
perf tools: Fix AAAAARGH64 memory barriers


tools/perf/builtin-buildid-cache.c | 33 ++++++++++++++++---
tools/perf/builtin-record.c | 10 ++----
tools/perf/design.txt | 1 -
tools/perf/perf.h | 4 +--
tools/perf/tests/vmlinux-kallsyms.c | 10 ------
tools/perf/util/event.c | 36 ++++++++++----------
tools/perf/util/event.h | 6 ++--
tools/perf/util/include/asm/hash.h | 6 ++++
tools/perf/util/machine.c | 42 +++++++++++++++++++-----
tools/perf/util/machine.h | 2 ++
tools/perf/util/map.c | 5 +--
tools/perf/util/map.h | 1 +
tools/perf/util/symbol-elf.c | 4 ++-
tools/perf/util/symbol.c | 65 +++++++++++++++++++++++++++++++++----
14 files changed, 162 insertions(+), 63 deletions(-)
create mode 100644 tools/perf/util/include/asm/hash.h

diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index cfede86..b22dbb1 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -63,11 +63,35 @@ static int build_id_cache__kcore_dir(char *dir, size_t sz)
return 0;
}

+static bool same_kallsyms_reloc(const char *from_dir, char *to_dir)
+{
+ char from[PATH_MAX];
+ char to[PATH_MAX];
+ const char *name;
+ u64 addr1 = 0, addr2 = 0;
+ int i;
+
+ scnprintf(from, sizeof(from), "%s/kallsyms", from_dir);
+ scnprintf(to, sizeof(to), "%s/kallsyms", to_dir);
+
+ for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
+ addr1 = kallsyms__get_function_start(from, name);
+ if (addr1)
+ break;
+ }
+
+ if (name)
+ addr2 = kallsyms__get_function_start(to, name);
+
+ return addr1 == addr2;
+}
+
static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
size_t to_dir_sz)
{
char from[PATH_MAX];
char to[PATH_MAX];
+ char to_subdir[PATH_MAX];
struct dirent *dent;
int ret = -1;
DIR *d;
@@ -86,10 +110,11 @@ static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
continue;
scnprintf(to, sizeof(to), "%s/%s/modules", to_dir,
dent->d_name);
- if (!compare_proc_modules(from, to)) {
- scnprintf(to, sizeof(to), "%s/%s", to_dir,
- dent->d_name);
- strlcpy(to_dir, to, to_dir_sz);
+ scnprintf(to_subdir, sizeof(to_subdir), "%s/%s",
+ to_dir, dent->d_name);
+ if (!compare_proc_modules(from, to) &&
+ same_kallsyms_reloc(from_dir, to_subdir)) {
+ strlcpy(to_dir, to_subdir, to_dir_sz);
ret = 0;
break;
}
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3c394bf..af47531 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -287,10 +287,7 @@ static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
* have no _text sometimes.
*/
err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
- machine, "_text");
- if (err < 0)
- err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
- machine, "_stext");
+ machine);
if (err < 0)
pr_err("Couldn't record guest kernel [%d]'s reference"
" relocation symbol.\n", machine->pid);
@@ -457,10 +454,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
}

err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
- machine, "_text");
- if (err < 0)
- err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
- machine, "_stext");
+ machine);
if (err < 0)
pr_err("Couldn't record kernel reference relocation symbol\n"
"Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
diff --git a/tools/perf/design.txt b/tools/perf/design.txt
index 67e5d0c..63a0e6f 100644
--- a/tools/perf/design.txt
+++ b/tools/perf/design.txt
@@ -454,7 +454,6 @@ So to start with, in order to add HAVE_PERF_EVENTS to your Kconfig, you
will need at least this:
- asm/perf_event.h - a basic stub will suffice at first
- support for atomic64 types (and associated helper functions)
- - set_perf_event_pending() implemented

If your architecture does have hardware capabilities, you can override the
weak stub hw_perf_event_init() to register hardware counters.
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 7daa806..e84fa26 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -100,8 +100,8 @@

#ifdef __aarch64__
#define mb() asm volatile("dmb ish" ::: "memory")
-#define wmb() asm volatile("dmb ishld" ::: "memory")
-#define rmb() asm volatile("dmb ishst" ::: "memory")
+#define wmb() asm volatile("dmb ishst" ::: "memory")
+#define rmb() asm volatile("dmb ishld" ::: "memory")
#define cpu_relax() asm volatile("yield" ::: "memory")
#endif

diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c
index 2bd13ed..3d90880 100644
--- a/tools/perf/tests/vmlinux-kallsyms.c
+++ b/tools/perf/tests/vmlinux-kallsyms.c
@@ -26,7 +26,6 @@ int test__vmlinux_matches_kallsyms(void)
struct map *kallsyms_map, *vmlinux_map;
struct machine kallsyms, vmlinux;
enum map_type type = MAP__FUNCTION;
- struct ref_reloc_sym ref_reloc_sym = { .name = "_stext", };
u64 mem_start, mem_end;

/*
@@ -70,14 +69,6 @@ int test__vmlinux_matches_kallsyms(void)
*/
kallsyms_map = machine__kernel_map(&kallsyms, type);

- sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
- if (sym == NULL) {
- pr_debug("dso__find_symbol_by_name ");
- goto out;
- }
-
- ref_reloc_sym.addr = UM(sym->start);
-
/*
* Step 5:
*
@@ -89,7 +80,6 @@ int test__vmlinux_matches_kallsyms(void)
}

vmlinux_map = machine__kernel_map(&vmlinux, type);
- map__kmap(vmlinux_map)->ref_reloc_sym = &ref_reloc_sym;

/*
* Step 6:
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 1fc1c2f..b0f3ca8 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -470,23 +470,32 @@ static int find_symbol_cb(void *arg, const char *name, char type,
return 1;
}

+u64 kallsyms__get_function_start(const char *kallsyms_filename,
+ const char *symbol_name)
+{
+ struct process_symbol_args args = { .name = symbol_name, };
+
+ if (kallsyms__parse(kallsyms_filename, &args, find_symbol_cb) <= 0)
+ return 0;
+
+ return args.start;
+}
+
int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
perf_event__handler_t process,
- struct machine *machine,
- const char *symbol_name)
+ struct machine *machine)
{
size_t size;
- const char *filename, *mmap_name;
- char path[PATH_MAX];
+ const char *mmap_name;
char name_buff[PATH_MAX];
struct map *map;
+ struct kmap *kmap;
int err;
/*
* We should get this from /sys/kernel/sections/.text, but till that is
* available use this, and after it is use this as a fallback for older
* kernels.
*/
- struct process_symbol_args args = { .name = symbol_name, };
union perf_event *event = zalloc((sizeof(event->mmap) +
machine->id_hdr_size));
if (event == NULL) {
@@ -502,30 +511,19 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
* see kernel/perf_event.c __perf_event_mmap
*/
event->header.misc = PERF_RECORD_MISC_KERNEL;
- filename = "/proc/kallsyms";
} else {
event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
- if (machine__is_default_guest(machine))
- filename = (char *) symbol_conf.default_guest_kallsyms;
- else {
- sprintf(path, "%s/proc/kallsyms", machine->root_dir);
- filename = path;
- }
- }
-
- if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0) {
- free(event);
- return -ENOENT;
}

map = machine->vmlinux_maps[MAP__FUNCTION];
+ kmap = map__kmap(map);
size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
- "%s%s", mmap_name, symbol_name) + 1;
+ "%s%s", mmap_name, kmap->ref_reloc_sym->name) + 1;
size = PERF_ALIGN(size, sizeof(u64));
event->mmap.header.type = PERF_RECORD_MMAP;
event->mmap.header.size = (sizeof(event->mmap) -
(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
- event->mmap.pgoff = args.start;
+ event->mmap.pgoff = kmap->ref_reloc_sym->addr;
event->mmap.start = map->start;
event->mmap.len = map->end - event->mmap.start;
event->mmap.pid = machine->pid;
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index faf6e21..851fa06 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -214,8 +214,7 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
struct machine *machine, bool mmap_data);
int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
perf_event__handler_t process,
- struct machine *machine,
- const char *symbol_name);
+ struct machine *machine);

int perf_event__synthesize_modules(struct perf_tool *tool,
perf_event__handler_t process,
@@ -279,4 +278,7 @@ size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp);
size_t perf_event__fprintf_task(union perf_event *event, FILE *fp);
size_t perf_event__fprintf(union perf_event *event, FILE *fp);

+u64 kallsyms__get_function_start(const char *kallsyms_filename,
+ const char *symbol_name);
+
#endif /* __PERF_RECORD_H */
diff --git a/tools/perf/util/include/asm/hash.h b/tools/perf/util/include/asm/hash.h
new file mode 100644
index 0000000..d82b170b
--- /dev/null
+++ b/tools/perf/util/include/asm/hash.h
@@ -0,0 +1,6 @@
+#ifndef __ASM_GENERIC_HASH_H
+#define __ASM_GENERIC_HASH_H
+
+/* Stub */
+
+#endif /* __ASM_GENERIC_HASH_H */
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index ded7459..c872991 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -496,19 +496,22 @@ static int symbol__in_kernel(void *arg, const char *name,
return 1;
}

+static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
+ size_t bufsz)
+{
+ if (machine__is_default_guest(machine))
+ scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
+ else
+ scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
+}
+
/* Figure out the start address of kernel map from /proc/kallsyms */
static u64 machine__get_kernel_start_addr(struct machine *machine)
{
- const char *filename;
- char path[PATH_MAX];
+ char filename[PATH_MAX];
struct process_args args;

- if (machine__is_default_guest(machine))
- filename = (char *)symbol_conf.default_guest_kallsyms;
- else {
- sprintf(path, "%s/proc/kallsyms", machine->root_dir);
- filename = path;
- }
+ machine__get_kallsyms_filename(machine, filename, PATH_MAX);

if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return 0;
@@ -829,9 +832,25 @@ static int machine__create_modules(struct machine *machine)
return 0;
}

+const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
+
int machine__create_kernel_maps(struct machine *machine)
{
struct dso *kernel = machine__get_kernel(machine);
+ char filename[PATH_MAX];
+ const char *name;
+ u64 addr = 0;
+ int i;
+
+ machine__get_kallsyms_filename(machine, filename, PATH_MAX);
+
+ for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
+ addr = kallsyms__get_function_start(filename, name);
+ if (addr)
+ break;
+ }
+ if (!addr)
+ return -1;

if (kernel == NULL ||
__machine__create_kernel_maps(machine, kernel) < 0)
@@ -850,6 +869,13 @@ int machine__create_kernel_maps(struct machine *machine)
* Now that we have all the maps created, just set the ->end of them:
*/
map_groups__fixup_end(&machine->kmaps);
+
+ if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
+ addr)) {
+ machine__destroy_kernel_maps(machine);
+ return -1;
+ }
+
return 0;
}

diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 4771330..f77e91e 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -18,6 +18,8 @@ union perf_event;
#define HOST_KERNEL_ID (-1)
#define DEFAULT_GUEST_KERNEL_ID (0)

+extern const char *ref_reloc_sym_names[];
+
struct machine {
struct rb_node rb_node;
pid_t pid;
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 3b97513..39cd2d0 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -39,6 +39,7 @@ void map__init(struct map *map, enum map_type type,
map->start = start;
map->end = end;
map->pgoff = pgoff;
+ map->reloc = 0;
map->dso = dso;
map->map_ip = map__map_ip;
map->unmap_ip = map__unmap_ip;
@@ -288,7 +289,7 @@ u64 map__rip_2objdump(struct map *map, u64 rip)
if (map->dso->rel)
return rip - map->pgoff;

- return map->unmap_ip(map, rip);
+ return map->unmap_ip(map, rip) - map->reloc;
}

/**
@@ -311,7 +312,7 @@ u64 map__objdump_2mem(struct map *map, u64 ip)
if (map->dso->rel)
return map->unmap_ip(map, ip + map->pgoff);

- return ip;
+ return ip + map->reloc;
}

void map_groups__init(struct map_groups *mg)
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 18068c6..257e513 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -36,6 +36,7 @@ struct map {
bool erange_warned;
u32 priv;
u64 pgoff;
+ u64 reloc;
u32 maj, min; /* only valid for MMAP2 record */
u64 ino; /* only valid for MMAP2 record */
u64 ino_generation;/* only valid for MMAP2 record */
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 7594567..3e9f336 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -751,6 +751,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
if (strcmp(elf_name, kmap->ref_reloc_sym->name))
continue;
kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
+ map->reloc = kmap->ref_reloc_sym->addr -
+ kmap->ref_reloc_sym->unrelocated_addr;
break;
}
}
@@ -922,6 +924,7 @@ int dso__load_sym(struct dso *dso, struct map *map,
(u64)shdr.sh_offset);
sym.st_value -= shdr.sh_addr - shdr.sh_offset;
}
+new_symbol:
/*
* We need to figure out if the object was created from C++ sources
* DWARF DW_compile_unit has this, but we don't always have access
@@ -933,7 +936,6 @@ int dso__load_sym(struct dso *dso, struct map *map,
if (demangled != NULL)
elf_name = demangled;
}
-new_symbol:
f = symbol__new(sym.st_value, sym.st_size,
GELF_ST_BIND(sym.st_info), elf_name);
free(demangled);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 39ce9ad..a9d758a 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -627,7 +627,7 @@ static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
* kernel range is broken in several maps, named [kernel].N, as we don't have
* the original ELF section names vmlinux have.
*/
-static int dso__split_kallsyms(struct dso *dso, struct map *map,
+static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
symbol_filter_t filter)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
@@ -692,6 +692,12 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map,
char dso_name[PATH_MAX];
struct dso *ndso;

+ if (delta) {
+ /* Kernel was relocated at boot time */
+ pos->start -= delta;
+ pos->end -= delta;
+ }
+
if (count == 0) {
curr_map = map;
goto filter_symbol;
@@ -721,6 +727,10 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map,
curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
map_groups__insert(kmaps, curr_map);
++kernel_range;
+ } else if (delta) {
+ /* Kernel was relocated at boot time */
+ pos->start -= delta;
+ pos->end -= delta;
}
filter_symbol:
if (filter && filter(curr_map, pos)) {
@@ -976,6 +986,23 @@ static int validate_kcore_modules(const char *kallsyms_filename,
return 0;
}

+static int validate_kcore_addresses(const char *kallsyms_filename,
+ struct map *map)
+{
+ struct kmap *kmap = map__kmap(map);
+
+ if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
+ u64 start;
+
+ start = kallsyms__get_function_start(kallsyms_filename,
+ kmap->ref_reloc_sym->name);
+ if (start != kmap->ref_reloc_sym->addr)
+ return -EINVAL;
+ }
+
+ return validate_kcore_modules(kallsyms_filename, map);
+}
+
struct kcore_mapfn_data {
struct dso *dso;
enum map_type type;
@@ -1019,8 +1046,8 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
kallsyms_filename))
return -EINVAL;

- /* All modules must be present at their original addresses */
- if (validate_kcore_modules(kallsyms_filename, map))
+ /* Modules and kernel must be present at their original addresses */
+ if (validate_kcore_addresses(kallsyms_filename, map))
return -EINVAL;

md.dso = dso;
@@ -1113,15 +1140,41 @@ out_err:
return -EINVAL;
}

+/*
+ * If the kernel is relocated at boot time, kallsyms won't match. Compute the
+ * delta based on the relocation reference symbol.
+ */
+static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
+{
+ struct kmap *kmap = map__kmap(map);
+ u64 addr;
+
+ if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
+ return 0;
+
+ addr = kallsyms__get_function_start(filename,
+ kmap->ref_reloc_sym->name);
+ if (!addr)
+ return -1;
+
+ *delta = addr - kmap->ref_reloc_sym->addr;
+ return 0;
+}
+
int dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map, symbol_filter_t filter)
{
+ u64 delta = 0;
+
if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return -1;

if (dso__load_all_kallsyms(dso, filename, map) < 0)
return -1;

+ if (kallsyms__delta(map, filename, &delta))
+ return -1;
+
symbols__fixup_duplicate(&dso->symbols[map->type]);
symbols__fixup_end(&dso->symbols[map->type]);

@@ -1133,7 +1186,7 @@ int dso__load_kallsyms(struct dso *dso, const char *filename,
if (!dso__load_kcore(dso, map, filename))
return dso__split_kallsyms_for_kcore(dso, map, filter);
else
- return dso__split_kallsyms(dso, map, filter);
+ return dso__split_kallsyms(dso, map, delta, filter);
}

static int dso__load_perf_map(struct dso *dso, struct map *map,
@@ -1424,7 +1477,7 @@ static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
continue;
scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
"%s/%s/kallsyms", dir, dent->d_name);
- if (!validate_kcore_modules(kallsyms_filename, map)) {
+ if (!validate_kcore_addresses(kallsyms_filename, map)) {
strlcpy(dir, kallsyms_filename, dir_sz);
ret = 0;
break;
@@ -1479,7 +1532,7 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
if (fd != -1) {
close(fd);
/* If module maps match go with /proc/kallsyms */
- if (!validate_kcore_modules("/proc/kallsyms", map))
+ if (!validate_kcore_addresses("/proc/kallsyms", map))
goto proc_kallsyms;
}

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