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SubjectRe: [PATCH v4 01/15] perf tools: Add utility function to fetch executable
Em Tue, Mar 05, 2019 at 06:47:44AM -0800, Andi Kleen escreveu:
> From: Andi Kleen <ak@linux.intel.com>
>
> Add a utility function to fetch executable code. Convert one
> user over to it. There are more places doing that, but they
> do significantly different actions, so they are not
> easy to fit into a single library function.
>
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
> tools/perf/util/Build | 1 +
> tools/perf/util/fetch.c | 28 ++++++++++++++++++++++++++++
> tools/perf/util/fetch.h | 7 +++++++
> tools/perf/util/intel-bts.c | 21 +++------------------
> 4 files changed, 39 insertions(+), 18 deletions(-)
> create mode 100644 tools/perf/util/fetch.c
> create mode 100644 tools/perf/util/fetch.h

So I've made some changes and the end result is below, will fixup the
following patches, holler if you find any problems:

Changes:

. No need to cast around, make 'buf' be a void pointer

. Rename it to thread__memcpy() to reflect the fact it is about copying
a chunk of memory from a thread, i.e. from its address space.

. No need to have it in a separate object file, move it to thread.[ch]

. Check the return of map__load(), the original code didn't do it, but
since we're moving this around, check that as well, could be moved to
a separate patch tho.

- Arnaldo

diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c
index 0c0180c67574..47025bc727e1 100644
--- a/tools/perf/util/intel-bts.c
+++ b/tools/perf/util/intel-bts.c
@@ -328,35 +328,19 @@ static int intel_bts_get_next_insn(struct intel_bts_queue *btsq, u64 ip)
{
struct machine *machine = btsq->bts->machine;
struct thread *thread;
- struct addr_location al;
unsigned char buf[INTEL_PT_INSN_BUF_SZ];
ssize_t len;
- int x86_64;
- uint8_t cpumode;
+ bool x86_64;
int err = -1;

- if (machine__kernel_ip(machine, ip))
- cpumode = PERF_RECORD_MISC_KERNEL;
- else
- cpumode = PERF_RECORD_MISC_USER;
-
thread = machine__find_thread(machine, -1, btsq->tid);
if (!thread)
return -1;

- if (!thread__find_map(thread, cpumode, ip, &al) || !al.map->dso)
- goto out_put;
-
- len = dso__data_read_addr(al.map->dso, al.map, machine, ip, buf,
- INTEL_PT_INSN_BUF_SZ);
+ len = thread__memcpy(thread, machine, buf, ip, INTEL_PT_INSN_BUF_SZ, &x86_64);
if (len <= 0)
goto out_put;

- /* Load maps to ensure dso->is_64_bit has been updated */
- map__load(al.map);
-
- x86_64 = al.map->dso->is_64_bit;
-
if (intel_pt_get_insn(buf, len, x86_64, &btsq->intel_pt_insn))
goto out_put;

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 4c179fef442d..50678d318185 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -12,6 +12,7 @@
#include "debug.h"
#include "namespaces.h"
#include "comm.h"
+#include "map.h"
#include "symbol.h"
#include "unwind.h"

@@ -393,3 +394,25 @@ struct thread *thread__main_thread(struct machine *machine, struct thread *threa

return machine__find_thread(machine, thread->pid_, thread->pid_);
}
+
+int thread__memcpy(struct thread *thread, struct machine *machine,
+ void *buf, u64 ip, int len, bool *is64bit)
+{
+ u8 cpumode = PERF_RECORD_MISC_USER;
+ struct addr_location al;
+ long offset;
+
+ if (machine__kernel_ip(machine, ip))
+ cpumode = PERF_RECORD_MISC_KERNEL;
+
+ if (!thread__find_map(thread, cpumode, ip, &al) || !al.map->dso ||
+ al.map->dso->data.status == DSO_DATA_STATUS_ERROR ||
+ map__load(al.map) < 0)
+ return -1;
+
+ offset = al.map->map_ip(al.map, ip);
+ if (is64bit)
+ *is64bit = al.map->dso->is_64_bit;
+
+ return dso__data_read_offset(al.map->dso, machine, offset, buf, len);
+}
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 8276ffeec556..cf8375c017a0 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -113,6 +113,9 @@ struct symbol *thread__find_symbol_fb(struct thread *thread, u8 cpumode,
void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
struct addr_location *al);

+int thread__memcpy(struct thread *thread, struct machine *machine,
+ void *buf, u64 ip, int len, bool *is64bit);
+
static inline void *thread__priv(struct thread *thread)
{
return thread->priv;
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