According to man pages of libunwind, unwind hooks should return 'negative value of one of the unw_error_t error-codes', they are different from generic error code. In addition, access_dso_mem() returns '!(size == sizeof(*data))', compiler never ensure it is negative when failure, which causes libunwind get undesire value when accessing //anon memory.
This patch fixes this problem by force returning negative value when error, instead of returning 'ret' itself when it is non-zero. Signed-off-by: Wang Nan <[email protected]> --- tools/perf/util/unwind-libunwind.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c index 7b09a44..78a32c7 100644 --- a/tools/perf/util/unwind-libunwind.c +++ b/tools/perf/util/unwind-libunwind.c @@ -422,7 +422,7 @@ static int access_dso_mem(struct unwind_info *ui, unw_word_t addr, size = dso__data_read_addr(al.map->dso, al.map, ui->machine, addr, (u8 *) data, sizeof(*data)); - return !(size == sizeof(*data)); + return (size == sizeof(*data)) ? 0 : -UNW_EINVAL; } static int access_mem(unw_addr_space_t __maybe_unused as, @@ -443,13 +443,13 @@ static int access_mem(unw_addr_space_t __maybe_unused as, ret = perf_reg_value(&start, &ui->sample->user_regs, PERF_REG_SP); if (ret) - return ret; + return -UNW_EBADREG; end = start + stack->size; /* Check overflow. */ if (addr + sizeof(unw_word_t) < addr) - return -EINVAL; + return -UNW_EINVAL; if (addr < start || addr + sizeof(unw_word_t) >= end) { ret = access_dso_mem(ui, addr, valp); @@ -491,12 +491,12 @@ static int access_reg(unw_addr_space_t __maybe_unused as, id = libunwind__arch_reg_id(regnum); if (id < 0) - return -EINVAL; + return -UNW_EBADREG; ret = perf_reg_value(&val, &ui->sample->user_regs, id); if (ret) { pr_err("unwind: can't read reg %d\n", regnum); - return ret; + return -UNW_EBADREG; } *valp = (unw_word_t) val; -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
