* [PATCH v2 1/4] perf tools: record aarch64 registers automatically
@ 2021-02-12 17:03 Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames Alexandre Truong
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Alexandre Truong @ 2021-02-12 17:03 UTC (permalink / raw)
To: linux-kernel, linux-perf-users; +Cc: Alexandre Truong
On arm64, automatically record all the registers if the frame pointer
mode is on. They will be used to do a dwarf unwind to find the caller
of the leaf frame if the frame pointer was omitted.
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
---
tools/perf/arch/arm64/util/machine.c | 7 +++++++
tools/perf/builtin-record.c | 7 +++++++
tools/perf/util/callchain.h | 2 ++
3 files changed, 16 insertions(+)
diff --git a/tools/perf/arch/arm64/util/machine.c b/tools/perf/arch/arm64/util/machine.c
index 40c5e0b5bda8..bf2f9c447867 100644
--- a/tools/perf/arch/arm64/util/machine.c
+++ b/tools/perf/arch/arm64/util/machine.c
@@ -5,6 +5,8 @@
#include <string.h>
#include "debug.h"
#include "symbol.h"
+#include "callchain.h"
+#include "record.h"
/* On arm64, kernel text segment start at high memory address,
* for example 0xffff 0000 8xxx xxxx. Modules start at a low memory
@@ -26,3 +28,8 @@ void arch__symbols__fixup_end(struct symbol *p, struct symbol *c)
p->end = c->start;
pr_debug4("%s sym:%s end:%#" PRIx64 "\n", __func__, p->name, p->end);
}
+
+void arch__add_leaf_frame_record_opts(struct record_opts *opts)
+{
+ opts->sample_user_regs = arch__user_reg_mask();
+}
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8a0127d4fb52..496307ef490e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2244,6 +2244,10 @@ static int record__parse_mmap_pages(const struct option *opt,
return ret;
}
+void __weak arch__add_leaf_frame_record_opts(struct record_opts *opts __maybe_unused)
+{
+}
+
static int parse_control_option(const struct option *opt,
const char *str,
int unset __maybe_unused)
@@ -2813,6 +2817,9 @@ int cmd_record(int argc, const char **argv)
/* Enable ignoring missing threads when -u/-p option is defined. */
rec->opts.ignore_missing_thread = rec->opts.target.uid != UINT_MAX || rec->opts.target.pid;
+ if (callchain_param.enabled && callchain_param.record_mode == CALLCHAIN_FP)
+ arch__add_leaf_frame_record_opts(&rec->opts);
+
err = -ENOMEM;
if (evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
usage_with_options(record_usage, record_options);
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 5824134f983b..77fba053c677 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -280,6 +280,8 @@ static inline int arch_skip_callchain_idx(struct thread *thread __maybe_unused,
}
#endif
+void arch__add_leaf_frame_record_opts(struct record_opts *opts);
+
char *callchain_list__sym_name(struct callchain_list *cl,
char *bf, size_t bfsize, bool show_dso);
char *callchain_node__scnprintf_value(struct callchain_node *node,
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames
2021-02-12 17:03 [PATCH v2 1/4] perf tools: record aarch64 registers automatically Alexandre Truong
@ 2021-02-12 17:03 ` Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 3/4] perf tools: enable dwarf_callchain_users on aarch64 Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 4/4] perf tools: determine if LR is the return address Alexandre Truong
2 siblings, 0 replies; 6+ messages in thread
From: Alexandre Truong @ 2021-02-12 17:03 UTC (permalink / raw)
To: linux-kernel, linux-perf-users; +Cc: Alexandre Truong
Add a mechanism for platforms to inject stack frames for the leaf
frame caller if there is enough information to determine a frame
is missing from dwarf or other post processing mechanisms.
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
---
tools/perf/util/machine.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index ab8a6b3e801d..7f03ffa016b0 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2671,6 +2671,12 @@ static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread,
return err;
}
+static u64 get_leaf_frame_caller(struct perf_sample *sample __maybe_unused,
+ struct thread *thread __maybe_unused)
+{
+ return 0;
+}
+
static int thread__resolve_callchain_sample(struct thread *thread,
struct callchain_cursor *cursor,
struct evsel *evsel,
@@ -2687,6 +2693,8 @@ static int thread__resolve_callchain_sample(struct thread *thread,
int i, j, err, nr_entries;
int skip_idx = -1;
int first_call = 0;
+ u64 leaf_frame_caller;
+ int pos;
if (chain)
chain_nr = chain->nr;
@@ -2811,6 +2819,21 @@ static int thread__resolve_callchain_sample(struct thread *thread,
continue;
}
+ pos = callchain_param.order == ORDER_CALLEE ? 2 : chain_nr - 2;
+
+ if (i == pos) {
+ leaf_frame_caller = get_leaf_frame_caller(sample, thread);
+
+ if (leaf_frame_caller && leaf_frame_caller != ip) {
+
+ err = add_callchain_ip(thread, cursor, parent,
+ root_al, &cpumode, leaf_frame_caller,
+ false, NULL, NULL, 0);
+ if (err)
+ return (err < 0) ? err : 0;
+ }
+ }
+
err = add_callchain_ip(thread, cursor, parent,
root_al, &cpumode, ip,
false, NULL, NULL, 0);
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v2 3/4] perf tools: enable dwarf_callchain_users on aarch64
2021-02-12 17:03 [PATCH v2 1/4] perf tools: record aarch64 registers automatically Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames Alexandre Truong
@ 2021-02-12 17:03 ` Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 4/4] perf tools: determine if LR is the return address Alexandre Truong
2 siblings, 0 replies; 6+ messages in thread
From: Alexandre Truong @ 2021-02-12 17:03 UTC (permalink / raw)
To: linux-kernel, linux-perf-users; +Cc: Alexandre Truong
On arm64, enable dwarf_callchain_users which will be needed
to do a dwarf unwind in order to get the caller of the leaf frame.
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
---
tools/perf/builtin-report.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 2a845d6cac09..93661a3eaeb1 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -405,6 +405,10 @@ static int report__setup_sample_type(struct report *rep)
callchain_param_setup(sample_type);
+ if (callchain_param.record_mode == CALLCHAIN_FP &&
+ strncmp(rep->session->header.env.arch, "aarch64", 7) == 0)
+ dwarf_callchain_users = true;
+
if (rep->stitch_lbr && (callchain_param.record_mode != CALLCHAIN_LBR)) {
ui__warning("Can't find LBR callchain. Switch off --stitch-lbr.\n"
"Please apply --call-graph lbr when recording.\n");
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v2 4/4] perf tools: determine if LR is the return address
2021-02-12 17:03 [PATCH v2 1/4] perf tools: record aarch64 registers automatically Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 3/4] perf tools: enable dwarf_callchain_users on aarch64 Alexandre Truong
@ 2021-02-12 17:03 ` Alexandre Truong
2021-02-16 10:47 ` Alexandre Truong
2 siblings, 1 reply; 6+ messages in thread
From: Alexandre Truong @ 2021-02-12 17:03 UTC (permalink / raw)
To: linux-kernel, linux-perf-users; +Cc: Alexandre Truong
On arm64 and frame pointer mode (e.g: perf record --callgraph fp),
use dwarf unwind info to check if the link register is the return
address in order to inject it to the frame pointer stack.
Write the following application:
int a = 10;
void f2(void)
{
for (int i = 0; i < 1000000; i++)
a *= a;
}
void f1()
{
for (int i = 0; i < 10; i++)
f2();
}
int main (void)
{
f1();
return 0;
}
with the following compilation flags:
gcc -fno-omit-frame-pointer -fno-inline -O2
The compiler omits the frame pointer for f2 on arm. This is a problem
with any leaf call, for example an application with many different
calls to malloc() would always omit the calling frame, even if it
can be determined.
./perf record --call-graph fp ./a.out
./perf report
currently gives the following stack:
0xffffea52f361
_start
__libc_start_main
main
f2
After this change, perf report correctly shows f1() calling f2(),
even though it was missing from the frame pointer unwind:
./perf report
0xffffea52f361
_start
__libc_start_main
main
f1
f2
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
---
tools/perf/util/Build | 1 +
.../util/arm-frame-pointer-unwind-support.c | 44 +++++++++++++++++++
.../util/arm-frame-pointer-unwind-support.h | 7 +++
tools/perf/util/machine.c | 9 ++--
4 files changed, 58 insertions(+), 3 deletions(-)
create mode 100644 tools/perf/util/arm-frame-pointer-unwind-support.c
create mode 100644 tools/perf/util/arm-frame-pointer-unwind-support.h
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 188521f34347..3b82cb992bce 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -1,3 +1,4 @@
+perf-y += arm-frame-pointer-unwind-support.o
perf-y += annotate.o
perf-y += block-info.o
perf-y += block-range.o
diff --git a/tools/perf/util/arm-frame-pointer-unwind-support.c b/tools/perf/util/arm-frame-pointer-unwind-support.c
new file mode 100644
index 000000000000..964efd08e72e
--- /dev/null
+++ b/tools/perf/util/arm-frame-pointer-unwind-support.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "../arch/arm64/include/uapi/asm/perf_regs.h"
+#include "arch/arm64/include/perf_regs.h"
+#include "event.h"
+#include "arm-frame-pointer-unwind-support.h"
+#include "callchain.h"
+#include "unwind.h"
+
+struct entries {
+ u64 stack[2];
+ size_t length;
+};
+
+static bool get_leaf_frame_caller_enabled(struct perf_sample *sample)
+{
+ return callchain_param.record_mode == CALLCHAIN_FP && sample->user_regs.regs
+ && sample->user_regs.mask == PERF_REGS_MASK;
+}
+
+static int add_entry(struct unwind_entry *entry, void *arg)
+{
+ struct entries *entries = arg;
+
+ entries->stack[entries->length++] = entry->ip;
+ return 0;
+}
+
+u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread)
+{
+ int ret;
+
+ struct entries entries = {{0, 0}, 0};
+
+ if (!get_leaf_frame_caller_enabled(sample))
+ return 0;
+
+ ret = unwind__get_entries(add_entry, &entries, thread, sample, 2);
+
+ if (ret || entries.length != 2)
+ return ret;
+
+ return callchain_param.order == ORDER_CALLER ?
+ entries.stack[0] : entries.stack[1];
+}
diff --git a/tools/perf/util/arm-frame-pointer-unwind-support.h b/tools/perf/util/arm-frame-pointer-unwind-support.h
new file mode 100644
index 000000000000..16dc03fa9abe
--- /dev/null
+++ b/tools/perf/util/arm-frame-pointer-unwind-support.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_ARM_FRAME_POINTER_UNWIND_SUPPORT_H
+#define __PERF_ARM_FRAME_POINTER_UNWIND_SUPPORT_H
+
+u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread);
+
+#endif /* __PERF_ARM_FRAME_POINTER_UNWIND_SUPPORT_H */
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 7f03ffa016b0..dfb72dbc0e2d 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -34,6 +34,7 @@
#include "bpf-event.h"
#include <internal/lib.h> // page_size
#include "cgroup.h"
+#include "arm-frame-pointer-unwind-support.h"
#include <linux/ctype.h>
#include <symbol/kallsyms.h>
@@ -2671,10 +2672,12 @@ static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread,
return err;
}
-static u64 get_leaf_frame_caller(struct perf_sample *sample __maybe_unused,
- struct thread *thread __maybe_unused)
+static u64 get_leaf_frame_caller(struct perf_sample *sample, struct thread *thread)
{
- return 0;
+ if (strncmp(thread->maps->machine->env->arch, "aarch64", 7) == 0)
+ return get_leaf_frame_caller_aarch64(sample, thread);
+ else
+ return 0;
}
static int thread__resolve_callchain_sample(struct thread *thread,
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v2 4/4] perf tools: determine if LR is the return address
2021-02-12 17:03 ` [PATCH v2 4/4] perf tools: determine if LR is the return address Alexandre Truong
@ 2021-02-16 10:47 ` Alexandre Truong
0 siblings, 0 replies; 6+ messages in thread
From: Alexandre Truong @ 2021-02-16 10:47 UTC (permalink / raw)
To: linux-kernel, linux-perf-users
Hi,
This patch is supposed to be a v3, I did a rebase.
Thanks,
Alexandre
On 2/12/21 5:03 PM, Alexandre Truong wrote:
> On arm64 and frame pointer mode (e.g: perf record --callgraph fp),
> use dwarf unwind info to check if the link register is the return
> address in order to inject it to the frame pointer stack.
>
> Write the following application:
>
> int a = 10;
>
> void f2(void)
> {
> for (int i = 0; i < 1000000; i++)
> a *= a;
> }
>
> void f1()
> {
> for (int i = 0; i < 10; i++)
> f2();
> }
>
> int main (void)
> {
> f1();
> return 0;
> }
>
> with the following compilation flags:
> gcc -fno-omit-frame-pointer -fno-inline -O2
>
> The compiler omits the frame pointer for f2 on arm. This is a problem
> with any leaf call, for example an application with many different
> calls to malloc() would always omit the calling frame, even if it
> can be determined.
>
> ./perf record --call-graph fp ./a.out
> ./perf report
>
> currently gives the following stack:
>
> 0xffffea52f361
> _start
> __libc_start_main
> main
> f2
>
> After this change, perf report correctly shows f1() calling f2(),
> even though it was missing from the frame pointer unwind:
>
> ./perf report
>
> 0xffffea52f361
> _start
> __libc_start_main
> main
> f1
> f2
>
> Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
> ---
> tools/perf/util/Build | 1 +
> .../util/arm-frame-pointer-unwind-support.c | 44 +++++++++++++++++++
> .../util/arm-frame-pointer-unwind-support.h | 7 +++
> tools/perf/util/machine.c | 9 ++--
> 4 files changed, 58 insertions(+), 3 deletions(-)
> create mode 100644 tools/perf/util/arm-frame-pointer-unwind-support.c
> create mode 100644 tools/perf/util/arm-frame-pointer-unwind-support.h
>
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 188521f34347..3b82cb992bce 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -1,3 +1,4 @@
> +perf-y += arm-frame-pointer-unwind-support.o
> perf-y += annotate.o
> perf-y += block-info.o
> perf-y += block-range.o
> diff --git a/tools/perf/util/arm-frame-pointer-unwind-support.c b/tools/perf/util/arm-frame-pointer-unwind-support.c
> new file mode 100644
> index 000000000000..964efd08e72e
> --- /dev/null
> +++ b/tools/perf/util/arm-frame-pointer-unwind-support.c
> @@ -0,0 +1,44 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include "../arch/arm64/include/uapi/asm/perf_regs.h"
> +#include "arch/arm64/include/perf_regs.h"
> +#include "event.h"
> +#include "arm-frame-pointer-unwind-support.h"
> +#include "callchain.h"
> +#include "unwind.h"
> +
> +struct entries {
> + u64 stack[2];
> + size_t length;
> +};
> +
> +static bool get_leaf_frame_caller_enabled(struct perf_sample *sample)
> +{
> + return callchain_param.record_mode == CALLCHAIN_FP && sample->user_regs.regs
> + && sample->user_regs.mask == PERF_REGS_MASK;
> +}
> +
> +static int add_entry(struct unwind_entry *entry, void *arg)
> +{
> + struct entries *entries = arg;
> +
> + entries->stack[entries->length++] = entry->ip;
> + return 0;
> +}
> +
> +u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread)
> +{
> + int ret;
> +
> + struct entries entries = {{0, 0}, 0};
> +
> + if (!get_leaf_frame_caller_enabled(sample))
> + return 0;
> +
> + ret = unwind__get_entries(add_entry, &entries, thread, sample, 2);
> +
> + if (ret || entries.length != 2)
> + return ret;
> +
> + return callchain_param.order == ORDER_CALLER ?
> + entries.stack[0] : entries.stack[1];
> +}
> diff --git a/tools/perf/util/arm-frame-pointer-unwind-support.h b/tools/perf/util/arm-frame-pointer-unwind-support.h
> new file mode 100644
> index 000000000000..16dc03fa9abe
> --- /dev/null
> +++ b/tools/perf/util/arm-frame-pointer-unwind-support.h
> @@ -0,0 +1,7 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __PERF_ARM_FRAME_POINTER_UNWIND_SUPPORT_H
> +#define __PERF_ARM_FRAME_POINTER_UNWIND_SUPPORT_H
> +
> +u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread);
> +
> +#endif /* __PERF_ARM_FRAME_POINTER_UNWIND_SUPPORT_H */
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 7f03ffa016b0..dfb72dbc0e2d 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -34,6 +34,7 @@
> #include "bpf-event.h"
> #include <internal/lib.h> // page_size
> #include "cgroup.h"
> +#include "arm-frame-pointer-unwind-support.h"
>
> #include <linux/ctype.h>
> #include <symbol/kallsyms.h>
> @@ -2671,10 +2672,12 @@ static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread,
> return err;
> }
>
> -static u64 get_leaf_frame_caller(struct perf_sample *sample __maybe_unused,
> - struct thread *thread __maybe_unused)
> +static u64 get_leaf_frame_caller(struct perf_sample *sample, struct thread *thread)
> {
> - return 0;
> + if (strncmp(thread->maps->machine->env->arch, "aarch64", 7) == 0)
> + return get_leaf_frame_caller_aarch64(sample, thread);
> + else
> + return 0;
> }
>
> static int thread__resolve_callchain_sample(struct thread *thread,
>
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/4] perf tools: record aarch64 registers automatically
@ 2021-02-10 13:22 Alexandre Truong
2021-02-10 13:22 ` [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames Alexandre Truong
0 siblings, 1 reply; 6+ messages in thread
From: Alexandre Truong @ 2021-02-10 13:22 UTC (permalink / raw)
To: linux-kernel, linux-perf-users; +Cc: Alexandre Truong
On arm64, automatically record all the registers if the frame pointer
mode is on. They will be used to do a dwarf unwind to find the caller
of the leaf frame if the frame pointer was omitted.
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
---
tools/perf/arch/arm64/util/machine.c | 7 +++++++
tools/perf/builtin-record.c | 7 +++++++
tools/perf/util/callchain.h | 2 ++
3 files changed, 16 insertions(+)
diff --git a/tools/perf/arch/arm64/util/machine.c b/tools/perf/arch/arm64/util/machine.c
index d41b27e781d3..8a8bab5f4e68 100644
--- a/tools/perf/arch/arm64/util/machine.c
+++ b/tools/perf/arch/arm64/util/machine.c
@@ -4,6 +4,8 @@
#include <string.h>
#include "debug.h"
#include "symbol.h"
+#include "callchain.h"
+#include "record.h"
/* On arm64, kernel text segment start at high memory address,
* for example 0xffff 0000 8xxx xxxx. Modules start at a low memory
@@ -25,3 +27,8 @@ void arch__symbols__fixup_end(struct symbol *p, struct symbol *c)
p->end = c->start;
pr_debug4("%s sym:%s end:%#lx\n", __func__, p->name, p->end);
}
+
+void arch__add_leaf_frame_record_opts(struct record_opts *opts)
+{
+ opts->sample_user_regs = arch__user_reg_mask();
+}
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 7bb10e9863bd..a5161f54b838 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2243,6 +2243,10 @@ static int record__parse_mmap_pages(const struct option *opt,
return ret;
}
+void __weak arch__add_leaf_frame_record_opts(struct record_opts *opts __maybe_unused)
+{
+}
+
static int parse_control_option(const struct option *opt,
const char *str,
int unset __maybe_unused)
@@ -2810,6 +2814,9 @@ int cmd_record(int argc, const char **argv)
/* Enable ignoring missing threads when -u/-p option is defined. */
rec->opts.ignore_missing_thread = rec->opts.target.uid != UINT_MAX || rec->opts.target.pid;
+ if (callchain_param.enabled && callchain_param.record_mode == CALLCHAIN_FP)
+ arch__add_leaf_frame_record_opts(&rec->opts);
+
err = -ENOMEM;
if (evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
usage_with_options(record_usage, record_options);
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 5824134f983b..77fba053c677 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -280,6 +280,8 @@ static inline int arch_skip_callchain_idx(struct thread *thread __maybe_unused,
}
#endif
+void arch__add_leaf_frame_record_opts(struct record_opts *opts);
+
char *callchain_list__sym_name(struct callchain_list *cl,
char *bf, size_t bfsize, bool show_dso);
char *callchain_node__scnprintf_value(struct callchain_node *node,
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames
2021-02-10 13:22 [PATCH v2 1/4] perf tools: record aarch64 registers automatically Alexandre Truong
@ 2021-02-10 13:22 ` Alexandre Truong
0 siblings, 0 replies; 6+ messages in thread
From: Alexandre Truong @ 2021-02-10 13:22 UTC (permalink / raw)
To: linux-kernel, linux-perf-users; +Cc: Alexandre Truong
Add a mechanism for platforms to inject stack frames for the leaf
frame caller if there is enough information to determine a frame
is missing from dwarf or other post processing mechanisms.
Signed-off-by: Alexandre Truong <alexandre.truong@arm.com>
---
tools/perf/util/machine.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 522ea3236bcc..40082d70eec1 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2671,6 +2671,12 @@ static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread,
return err;
}
+static u64 get_leaf_frame_caller(struct perf_sample *sample __maybe_unused,
+ struct thread *thread __maybe_unused)
+{
+ return 0;
+}
+
static int thread__resolve_callchain_sample(struct thread *thread,
struct callchain_cursor *cursor,
struct evsel *evsel,
@@ -2687,6 +2693,8 @@ static int thread__resolve_callchain_sample(struct thread *thread,
int i, j, err, nr_entries;
int skip_idx = -1;
int first_call = 0;
+ u64 leaf_frame_caller;
+ int pos;
if (chain)
chain_nr = chain->nr;
@@ -2811,6 +2819,21 @@ static int thread__resolve_callchain_sample(struct thread *thread,
continue;
}
+ pos = callchain_param.order == ORDER_CALLEE ? 2 : chain_nr - 2;
+
+ if (i == pos) {
+ leaf_frame_caller = get_leaf_frame_caller(sample, thread);
+
+ if (leaf_frame_caller && leaf_frame_caller != ip) {
+
+ err = add_callchain_ip(thread, cursor, parent,
+ root_al, &cpumode, leaf_frame_caller,
+ false, NULL, NULL, 0);
+ if (err)
+ return (err < 0) ? err : 0;
+ }
+ }
+
err = add_callchain_ip(thread, cursor, parent,
root_al, &cpumode, ip,
false, NULL, NULL, 0);
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-02-16 10:48 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-02-12 17:03 [PATCH v2 1/4] perf tools: record aarch64 registers automatically Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 3/4] perf tools: enable dwarf_callchain_users on aarch64 Alexandre Truong
2021-02-12 17:03 ` [PATCH v2 4/4] perf tools: determine if LR is the return address Alexandre Truong
2021-02-16 10:47 ` Alexandre Truong
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2021-02-10 13:22 [PATCH v2 1/4] perf tools: record aarch64 registers automatically Alexandre Truong
2021-02-10 13:22 ` [PATCH v2 2/4] perf tools: add a mechanism to inject stack frames Alexandre Truong
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