Hi Aruna,
On Tue, 31 Jan 2012 15:56:33 +0530
Aruna Balakrishnaiah <aruna at linux.vnet.ibm.com> wrote:
>
> The patch fixes the segmentation fault issue of makedumpfile when a
> user specifies an invalid file name with -x/--split option.
> The patch takes care of such a scenario by setting .find_debuginfo to
> a function pointer which returns -1 and throws error messages against
> invalid vmlinux file input. With a valid vmlinux file .find_debuginfo
> was never invoked since the absolute path of debuginfo was known by the
> time we call init_dwarf_info.
>
> Signed-off-by: Aruna Balakrishnaiah <aruna at linux.vnet.ibm.com>
> ---
> dwarf_info.c | 25 +++++++++++++++++++++++++
> 1 files changed, 25 insertions(+), 0 deletions(-)
Thank you for your patch.
I will review it.
Thanks
Atsushi Kumagai
> diff --git a/dwarf_info.c b/dwarf_info.c
> index 46dcd8e..515455d 100644
> --- a/dwarf_info.c
> +++ b/dwarf_info.c
> @@ -204,6 +204,16 @@ search_module_debuginfo(char *os_release)
> return FALSE;
> }
>
> +static int
> +dwarf_no_debuginfo_found(Dwfl_Module *mod, void **userdata,
> + const char *modname, Dwarf_Addr base,
> + const char *file_name,
> + const char *debuglink_file, GElf_Word debuglink_crc,
> + char **debuginfo_file_name)
> +{
> + return -1;
> +}
> +
> /*
> * Initialize the dwarf info.
> * Linux kernel module debuginfo are of ET_REL (relocatable) type.
> @@ -219,6 +229,21 @@ init_dwarf_info(void)
> int dwfl_fd = -1;
> static const Dwfl_Callbacks callbacks = {
> .section_address = dwfl_offline_section_address,
> + /*
> + * By the time init_dwarf_info() function is called, we already
> + * know absolute path of debuginfo either resolved through
> + * search_module_debuginfo() call OR user specified vmlinux
> + * debuginfo through '-x' option. In which case .find_debuginfo
> + * callback is never invoked.
> + * But we can not deny a situation where user may pass invalid
> + * file name through '-x' option, where .find_debuginfo gets
> + * invoked to find a valid vmlinux debuginfo and hence we run
> + * into seg fault issue. Hence, set .find_debuginfo to a
> + * funtion pointer that returns -1 to avoid seg fault and let
> + * the makedumpfile throw error messages against the invalid
> + * vmlinux file input.
> + */
> + .find_debuginfo = dwarf_no_debuginfo_found
> };
>
> dwarf_info.elfd = NULL;
>
>
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