On 03/02/17 at 05:39pm, Baoquan He wrote:
> Function get_kernel_sym in kexec will search /proc/kallsyms for
> kernel symbol and print error message anyway if expected symbol
> is not found. While page_offset_base definition and exporting
> codes are only available when mm KASLR code is compiled in kernel.
> Otherwise search will fail and print out error message, obviously
> this is false positive warning.
This doesn't work, I must have been dizzy yesterday, NACK it. Will
repost with a new one.
>
> So in this patch take out the error message from get_kernel_sym and
> put it where get_kernel_sym is called and expected symbol is not found.
>
> Signed-off-by: Baoquan He <bhe at redhat.com>
> ---
> kexec/arch/i386/crashdump-x86.c | 41 +++++++++++++++++++++++------------------
> 1 file changed, 23 insertions(+), 18 deletions(-)
>
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index 88aeee3..b9adc8c 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -127,7 +127,6 @@ static unsigned long long get_kernel_sym(const char *symbol)
> }
> }
>
> - fprintf(stderr, "Cannot get kernel %s symbol address\n", symbol);
> return 0;
> }
>
> @@ -193,30 +192,36 @@ static int get_kernel_vaddr_and_size(struct kexec_info *UNUSED(info),
> }
> if (lowest_vaddr != 0)
> elf_info->page_offset = lowest_vaddr;
> + } else {
> + fprintf(stderr, "Cannot get kernel page_offset_base symbol address\n");
> }
>
> /* Traverse through the Elf headers and find the region where
> * _stext symbol is located in. That's where kernel is mapped */
> stext_sym = get_kernel_sym("_stext");
> - for(phdr = ehdr.e_phdr; stext_sym && phdr != end_phdr; phdr++) {
> - if (phdr->p_type == PT_LOAD) {
> - unsigned long long saddr = phdr->p_vaddr;
> - unsigned long long eaddr = phdr->p_vaddr + phdr->p_memsz;
> - unsigned long long size;
> -
> - /* Look for kernel text mapping header. */
> - if (saddr <= stext_sym && eaddr > stext_sym) {
> - saddr = _ALIGN_DOWN(saddr, X86_64_KERN_VADDR_ALIGN);
> - elf_info->kern_vaddr_start = saddr;
> - size = eaddr - saddr;
> - /* Align size to page size boundary. */
> - size = _ALIGN(size, align);
> - elf_info->kern_size = size;
> - dbgprintf("kernel vaddr = 0x%llx size = 0x%llx\n",
> - saddr, size);
> - return 0;
> + if (stext_sym) {
> + for(phdr = ehdr.e_phdr; stext_sym && phdr != end_phdr; phdr++) {
> + if (phdr->p_type == PT_LOAD) {
> + unsigned long long saddr = phdr->p_vaddr;
> + unsigned long long eaddr = phdr->p_vaddr + phdr->p_memsz;
> + unsigned long long size;
> +
> + /* Look for kernel text mapping header. */
> + if (saddr <= stext_sym && eaddr > stext_sym) {
> + saddr = _ALIGN_DOWN(saddr, X86_64_KERN_VADDR_ALIGN);
> + elf_info->kern_vaddr_start = saddr;
> + size = eaddr - saddr;
> + /* Align size to page size boundary. */
> + size = _ALIGN(size, align);
> + elf_info->kern_size = size;
> + dbgprintf("kernel vaddr = 0x%llx size = 0x%llx\n",
> + saddr, size);
> + return 0;
> + }
> }
> }
> + } else {
> + fprintf(stderr, "Cannot get kernel _stext symbol address\n");
> }
>
> /* If failed to retrieve kernel text mapping through
> --
> 2.5.5
>
>
> _______________________________________________
> kexec mailing list
> kexec at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
