On Mon, Jul 24, 2023 at 4:48 PM HAGIO KAZUHITO(萩尾 一仁) <k-hagio...@nec.com>
wrote:
> From: Kazuhito Hagio <k-hagio...@nec.com>
>
> 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 <liji...@redhat.com>
> Signed-off-by: Kazuhito Hagio <k-hagio...@nec.com>
> ---
> 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
Lianbo
> --
> 2.31.1
>
>
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