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perf dso: Move read_symbol() from llvm/capstone to dso

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Move the read_symbol function to dso.h, make the return type const and
add a mutable out_buf out parameter.

In future changes this will allow a code pointer to be returned without
necessary allocating memory.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Haibo Xu <haibo1.xu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers
2025-10-05 14:22:04 -07:00
committed by Arnaldo Carvalho de Melo
parent 0e52f3f9f1
commit 9518e10c2b
4 changed files with 97 additions and 128 deletions
Download Patch File Download Diff File Expand all files Collapse all files

66
tools/perf/util/capstone.c
View File

@@ -215,55 +215,6 @@ static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
}
#endif
#ifdef HAVE_LIBCAPSTONE_SUPPORT
static u8 *
read_symbol(const char *filename, struct map *map, struct symbol *sym,
u64 *len, bool *is_64bit)
{
struct dso *dso = map__dso(map);
struct nscookie nsc;
u64 start = map__rip_2objdump(map, sym->start);
u64 end = map__rip_2objdump(map, sym->end);
int fd, count;
u8 *buf = NULL;
struct find_file_offset_data data = {
.ip = start,
};
*is_64bit = false;
nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
fd = open(filename, O_RDONLY);
nsinfo__mountns_exit(&nsc);
if (fd < 0)
return NULL;
if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data,
is_64bit) == 0)
goto err;
*len = end - start;
buf = malloc(*len);
if (buf == NULL)
goto err;
count = pread(fd, buf, *len, data.offset);
close(fd);
fd = -1;
if ((u64)count != *len)
goto err;
return buf;
err:
if (fd >= 0)
close(fd);
free(buf);
return NULL;
}
#endif
int symbol__disassemble_capstone(const char *filename __maybe_unused,
struct symbol *sym __maybe_unused,
struct annotate_args *args __maybe_unused)
@@ -271,13 +222,17 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
#ifdef HAVE_LIBCAPSTONE_SUPPORT
struct annotation *notes = symbol__annotation(sym);
struct map *map = args->ms.map;
struct dso *dso = map__dso(map);
u64 start = map__rip_2objdump(map, sym->start);
u64 len;
u64 offset;
int i, count, free_count;
bool is_64bit = false;
bool needs_cs_close = false;
u8 *buf = NULL;
/* Malloc-ed buffer containing instructions read from disk. */
u8 *code_buf = NULL;
/* Pointer to code to be disassembled. */
const u8 *buf;
u64 buf_len;
csh handle;
cs_insn *insn = NULL;
char disasm_buf[512];
@@ -287,7 +242,8 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
if (args->options->objdump_path)
return -1;
buf = read_symbol(filename, map, sym, &len, &is_64bit);
buf = dso__read_symbol(dso, filename, map, sym,
&code_buf, &buf_len, &is_64bit);
if (buf == NULL)
return -1;
@@ -316,7 +272,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
needs_cs_close = true;
free_count = count = cs_disasm(handle, buf, len, start, len, &insn);
free_count = count = cs_disasm(handle, buf, buf_len, start, buf_len, &insn);
for (i = 0, offset = 0; i < count; i++) {
int printed;
@@ -340,7 +296,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
}
/* It failed in the middle: probably due to unknown instructions */
if (offset != len) {
if (offset != buf_len) {
struct list_head *list = &notes->src->source;
/* Discard all lines and fallback to objdump */
@@ -359,7 +315,7 @@ int symbol__disassemble_capstone(const char *filename __maybe_unused,
if (free_count > 0)
cs_free(insn, free_count);
}
free(buf);
free(code_buf);
return count < 0 ? count : 0;
err:

67
tools/perf/util/dso.c
View File

@@ -1798,3 +1798,70 @@ bool is_perf_pid_map_name(const char *dso_name)
return perf_pid_map_tid(dso_name, &tid);
}
struct find_file_offset_data {
u64 ip;
u64 offset;
};
/* This will be called for each PHDR in an ELF binary */
static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
{
struct find_file_offset_data *data = arg;
if (start <= data->ip && data->ip < start + len) {
data->offset = pgoff + data->ip - start;
return 1;
}
return 0;
}
const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
const struct map *map, const struct symbol *sym,
u8 **out_buf, u64 *out_buf_len, bool *is_64bit)
{
struct nscookie nsc;
u64 start = map__rip_2objdump(map, sym->start);
u64 end = map__rip_2objdump(map, sym->end);
int fd, count;
u8 *buf = NULL;
size_t len;
struct find_file_offset_data data = {
.ip = start,
};
*out_buf = NULL;
*out_buf_len = 0;
*is_64bit = false;
nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
fd = open(symfs_filename, O_RDONLY);
nsinfo__mountns_exit(&nsc);
if (fd < 0)
return NULL;
if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, is_64bit) == 0)
goto err;
len = end - start;
buf = malloc(len);
if (buf == NULL)
goto err;
count = pread(fd, buf, len, data.offset);
close(fd);
fd = -1;
if ((u64)count != len)
goto err;
*out_buf = buf;
*out_buf_len = len;
return buf;
err:
if (fd >= 0)
close(fd);
free(buf);
return NULL;
}

4
tools/perf/util/dso.h
View File

@@ -924,4 +924,8 @@ static inline struct debuginfo *dso__debuginfo(struct dso *dso)
return debuginfo__new(dso__long_name(dso));
}
const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
const struct map *map, const struct symbol *sym,
u8 **out_buf, u64 *out_buf_len, bool *is_64bit);
#endif /* __PERF_DSO */

88
tools/perf/util/llvm.c
View File

@@ -87,71 +87,6 @@ static void init_llvm(void)
}
}
struct find_file_offset_data {
u64 ip;
u64 offset;
};
/* This will be called for each PHDR in an ELF binary */
static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg)
{
struct find_file_offset_data *data = arg;
if (start <= data->ip && data->ip < start + len) {
data->offset = pgoff + data->ip - start;
return 1;
}
return 0;
}
static u8 *
read_symbol(const char *filename, struct map *map, struct symbol *sym,
u64 *len, bool *is_64bit)
{
struct dso *dso = map__dso(map);
struct nscookie nsc;
u64 start = map__rip_2objdump(map, sym->start);
u64 end = map__rip_2objdump(map, sym->end);
int fd, count;
u8 *buf = NULL;
struct find_file_offset_data data = {
.ip = start,
};
*is_64bit = false;
nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
fd = open(filename, O_RDONLY);
nsinfo__mountns_exit(&nsc);
if (fd < 0)
return NULL;
if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data,
is_64bit) == 0)
goto err;
*len = end - start;
buf = malloc(*len);
if (buf == NULL)
goto err;
count = pread(fd, buf, *len, data.offset);
close(fd);
fd = -1;
if ((u64)count != *len)
goto err;
return buf;
err:
if (fd >= 0)
close(fd);
free(buf);
return NULL;
}
#endif
/*
* Whenever LLVM wants to resolve an address into a symbol, it calls this
* callback. We don't ever actually _return_ anything (in particular, because
@@ -160,7 +95,6 @@ read_symbol(const char *filename, struct map *map, struct symbol *sym,
* should add some textual annotation for after the instruction. The caller
* will use this information to add the actual annotation.
*/
#ifdef HAVE_LIBLLVM_SUPPORT
struct symbol_lookup_storage {
u64 branch_addr;
u64 pcrel_load_addr;
@@ -191,8 +125,11 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
struct map *map = args->ms.map;
struct dso *dso = map__dso(map);
u64 start = map__rip_2objdump(map, sym->start);
u8 *buf;
u64 len;
/* Malloc-ed buffer containing instructions read from disk. */
u8 *code_buf = NULL;
/* Pointer to code to be disassembled. */
const u8 *buf;
u64 buf_len;
u64 pc;
bool is_64bit;
char disasm_buf[2048];
@@ -207,7 +144,8 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
if (args->options->objdump_path)
return -1;
buf = read_symbol(filename, map, sym, &len, &is_64bit);
buf = dso__read_symbol(dso, filename, map, sym,
&code_buf, &buf_len, &is_64bit);
if (buf == NULL)
return -1;
@@ -259,14 +197,18 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
annotation_line__add(&dl->al, &notes->src->source);
pc = start;
for (u64 offset = 0; offset < len; ) {
for (u64 offset = 0; offset < buf_len; ) {
unsigned int ins_len;
storage.branch_addr = 0;
storage.pcrel_load_addr = 0;
ins_len = LLVMDisasmInstruction(disasm, buf + offset,
len - offset, pc,
/*
* LLVM's API has the code be disassembled as non-const, cast
* here as we may be disassembling from mapped read-only memory.
*/
ins_len = LLVMDisasmInstruction(disasm, (u8 *)(buf + offset),
buf_len - offset, pc,
disasm_buf, sizeof(disasm_buf));
if (ins_len == 0)
goto err;
@@ -324,7 +266,7 @@ int symbol__disassemble_llvm(const char *filename, struct symbol *sym,
err:
LLVMDisasmDispose(disasm);
free(buf);
free(code_buf);
free(line_storage);
return ret;
#else // HAVE_LIBLLVM_SUPPORT