On 2023/07/24 18:05, lijiang wrote:
> On Mon, Jul 24, 2023 at 4:48 PM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx>
> wrote:
>
>> From: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
>>
>> As written in the previous patch, some recent kernels do not have the
>> ".rodata" symbol. As a result, the get_linux_banner_from_vmlinux()
>> returns FALSE and the slower fallback routine is used.
>>
>> Use "__start_rodata" symbol if the ".rodata" symbol is not available.
>>
>> Reported-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
>> Signed-off-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
>> ---
>> Note that I chose to use ".rodata" first to not change the current
>> stable behavior for old vmcores, in this case.
>>
>> kernel.c | 9 +++++++--
>> 1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel.c b/kernel.c
>> index 9801812387bd..2114700eecc8 100644
>> --- a/kernel.c
>> +++ b/kernel.c
>> @@ -11891,8 +11891,13 @@ int get_linux_banner_from_vmlinux(char *buf,
>> size_t size)
>> {
>> struct bfd_section *sect;
>> long offset;
>> + ulong start_rodata;
>>
>> - if (!kernel_symbol_exists(".rodata"))
>> + if (kernel_symbol_exists(".rodata"))
>> + start_rodata = symbol_value(".rodata");
>> + else if (kernel_symbol_exists("__start_rodata"))
>> + start_rodata = symbol_value("__start_rodata");
>> + else
>> return FALSE;
>>
>> sect = bfd_get_section_by_name(st->bfd, ".rodata");
>> @@ -11905,7 +11910,7 @@ int get_linux_banner_from_vmlinux(char *buf,
>> size_t size)
>> * value in vmlinux file, but relative offset to linux_banner
>> * object in .rodata section is idential.
>> */
>> - offset = symbol_value("linux_banner") - symbol_value(".rodata");
>> + offset = symbol_value("linux_banner") - start_rodata;
>>
>> if (!bfd_get_section_contents(st->bfd,
>> sect,
>>
>
> Looks good to me. So: Ack.
Thanks, applied.
Kazu
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