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    Subject[PATCH 01/15] perf tests: Take into account address of each objdump line
    Date
    From: Jan Stancek <jstancek@redhat.com>

    objdump output can contain repeated bytes. At the moment test reads all
    output sequentially, assuming each address is represented in output only
    once:

    ffffffff8164efb3 <retint_swapgs+0x9>:
    ffffffff8164efb3: c1 5d 00 eb rcrl $0xeb,0x0(%rbp)
    ffffffff8164efb7: 00 4c 8b 5c add %cl,0x5c(%rbx,%rcx,4)

    ffffffff8164efb8 <restore_c_regs_and_iret>:
    ffffffff8164efb8: 4c 8b 5c 24 30 mov 0x30(%rsp),%r11
    ffffffff8164efbd: 4c 8b 54 24 38 mov 0x38(%rsp),%r10

    Store objdump output to buffer according to offset calculated from
    address on each line.

    Signed-off-by: Jan Stancek <jstancek@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>
    Link: http://lkml.kernel.org/r/ad13289a55d6350f7717757c7e32c2d4286402bd.1441181335.git.jstancek@redhat.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    ---
    tools/perf/tests/code-reading.c | 51 ++++++++++++++++++++++++++++++-----------
    1 file changed, 38 insertions(+), 13 deletions(-)

    diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
    index 39c784a100a9..38ee90bc2228 100644
    --- a/tools/perf/tests/code-reading.c
    +++ b/tools/perf/tests/code-reading.c
    @@ -33,20 +33,20 @@ static unsigned int hex(char c)
    return c - 'A' + 10;
    }

    -static void read_objdump_line(const char *line, size_t line_len, void **buf,
    - size_t *len)
    +static size_t read_objdump_line(const char *line, size_t line_len, void *buf,
    + size_t len)
    {
    const char *p;
    - size_t i;
    + size_t i, j = 0;

    /* Skip to a colon */
    p = strchr(line, ':');
    if (!p)
    - return;
    + return 0;
    i = p + 1 - line;

    /* Read bytes */
    - while (*len) {
    + while (j < len) {
    char c1, c2;

    /* Skip spaces */
    @@ -65,20 +65,26 @@ static void read_objdump_line(const char *line, size_t line_len, void **buf,
    if (i < line_len && line[i] && !isspace(line[i]))
    break;
    /* Store byte */
    - *(unsigned char *)*buf = (hex(c1) << 4) | hex(c2);
    - *buf += 1;
    - *len -= 1;
    + *(unsigned char *)buf = (hex(c1) << 4) | hex(c2);
    + buf += 1;
    + j++;
    }
    + /* return number of successfully read bytes */
    + return j;
    }

    -static int read_objdump_output(FILE *f, void **buf, size_t *len)
    +static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr)
    {
    char *line = NULL;
    - size_t line_len;
    + size_t line_len, off_last = 0;
    ssize_t ret;
    int err = 0;
    + u64 addr;
    +
    + while (off_last < *len) {
    + size_t off, read_bytes, written_bytes;
    + unsigned char tmp[BUFSZ];

    - while (1) {
    ret = getline(&line, &line_len, f);
    if (feof(f))
    break;
    @@ -87,9 +93,28 @@ static int read_objdump_output(FILE *f, void **buf, size_t *len)
    err = -1;
    break;
    }
    - read_objdump_line(line, ret, buf, len);
    +
    + /* read objdump data into temporary buffer */
    + read_bytes = read_objdump_line(line, ret, tmp, sizeof(tmp));
    + if (!read_bytes)
    + continue;
    +
    + if (sscanf(line, "%"PRIx64, &addr) != 1)
    + continue;
    +
    + /* copy it from temporary buffer to 'buf' according
    + * to address on current objdump line */
    + off = addr - start_addr;
    + if (off >= *len)
    + break;
    + written_bytes = MIN(read_bytes, *len - off);
    + memcpy(buf + off, tmp, written_bytes);
    + off_last = off + written_bytes;
    }

    + /* len returns number of bytes that could not be read */
    + *len -= off_last;
    +
    free(line);

    return err;
    @@ -120,7 +145,7 @@ static int read_via_objdump(const char *filename, u64 addr, void *buf,
    return -1;
    }

    - ret = read_objdump_output(f, &buf, &len);
    + ret = read_objdump_output(f, buf, &len, addr);
    if (len) {
    pr_debug("objdump read too few bytes\n");
    if (!ret)
    --
    2.1.0


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