Messages in this thread Patch in this message | | | From | Jan Stancek <> | Subject | [PATCH] perf tests: objdump output can contain multi byte chunks | Date | Tue, 12 Jan 2016 11:07:44 +0100 |
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objdump's raw insn output can vary across architectures on number of bytes per chunk (bpc) displayed and their endian.
code-reading test relied on reading objdump output as 1 bpc. Kaixu Xia reported test failure on ARM64, where objdump displays 4 bpc: 70c48: f90027bf str xzr, [x29,#72] 70c4c: 91224000 add x0, x0, #0x890 70c50: f90023a0 str x0, [x29,#64]
This patch adds support to read raw insn output for any bpc length. In case of 2+ bpc it also guesses objdump's display endian.
Signed-off-by: Jan Stancek <jstancek@redhat.com> Reported-and-tested-by: Kaixu Xia <xiakaixu@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> --- tools/perf/tests/code-reading.c | 100 ++++++++++++++++++++++++++++------------ 1 file changed, 71 insertions(+), 29 deletions(-)
diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c index a767a6400c5c..0108cb22d1a2 100644 --- a/tools/perf/tests/code-reading.c +++ b/tools/perf/tests/code-reading.c @@ -33,44 +33,86 @@ static unsigned int hex(char c) return c - 'A' + 10; } -static size_t read_objdump_line(const char *line, size_t line_len, void *buf, - size_t len) +static size_t read_objdump_chunk(const char **line, unsigned char **buf, + size_t *buf_len) +{ + size_t bytes_read = 0; + unsigned char *chunk_start = *buf; + + /* Read bytes */ + while (*buf_len > 0) { + char c1, c2; + + /* Get 2 hex digits */ + c1 = *(*line)++; + if (!isxdigit(c1)) + break; + c2 = *(*line)++; + if (!isxdigit(c2)) + break; + + /* Store byte and advance buf */ + **buf = (hex(c1) << 4) | hex(c2); + (*buf)++; + (*buf_len)--; + bytes_read++; + + /* End of chunk? */ + if (isspace(**line)) + break; + } + + /* + * objdump will display raw insn as LE if code endian + * is LE and bytes_per_chunk > 1. In that case reverse + * the chunk we just read. + * + * see disassemble_bytes() at binutils/objdump.c for details + * how objdump chooses display endian) + */ + if (bytes_read > 1 && !bigendian()) { + unsigned char *chunk_end = chunk_start + bytes_read - 1; + unsigned char tmp; + + while (chunk_start < chunk_end) { + tmp = *chunk_start; + *chunk_start = *chunk_end; + *chunk_end = tmp; + chunk_start++; + chunk_end--; + } + } + + return bytes_read; +} + +static size_t read_objdump_line(const char *line, unsigned char *buf, + size_t buf_len) { const char *p; - size_t i, j = 0; + size_t ret, bytes_read = 0; /* Skip to a colon */ p = strchr(line, ':'); if (!p) return 0; - i = p + 1 - line; + p++; - /* Read bytes */ - while (j < len) { - char c1, c2; - - /* Skip spaces */ - for (; i < line_len; i++) { - if (!isspace(line[i])) - break; - } - /* Get 2 hex digits */ - if (i >= line_len || !isxdigit(line[i])) - break; - c1 = line[i++]; - if (i >= line_len || !isxdigit(line[i])) - break; - c2 = line[i++]; - /* Followed by a space */ - if (i < line_len && line[i] && !isspace(line[i])) + /* Skip initial spaces */ + while (*p) { + if (!isspace(*p)) break; - /* Store byte */ - *(unsigned char *)buf = (hex(c1) << 4) | hex(c2); - buf += 1; - j++; + p++; } + + do { + ret = read_objdump_chunk(&p, &buf, &buf_len); + bytes_read += ret; + p++; + } while (ret > 0); + /* return number of successfully read bytes */ - return j; + return bytes_read; } static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) @@ -95,7 +137,7 @@ static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) } /* read objdump data into temporary buffer */ - read_bytes = read_objdump_line(line, ret, tmp, sizeof(tmp)); + read_bytes = read_objdump_line(line, tmp, sizeof(tmp)); if (!read_bytes) continue; @@ -152,7 +194,7 @@ static int read_via_objdump(const char *filename, u64 addr, void *buf, ret = read_objdump_output(f, buf, &len, addr); if (len) { - pr_debug("objdump read too few bytes\n"); + pr_debug("objdump read too few bytes: %lu\n", len); if (!ret) ret = len; } -- 1.8.3.1
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