On 02/27/18 at 01:48pm, AKASHI Takahiro wrote:
> removing bufp variable in prepare_elf64_headers() makes the code simpler
> and more understandable.
>
> Signed-off-by: AKASHI Takahiro <[email protected]>
> Cc: Dave Young <[email protected]>
> Cc: Vivek Goyal <[email protected]>
> Cc: Baoquan He <[email protected]>
> ---
> arch/x86/kernel/crash.c | 18 +++++++-----------
> 1 file changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index bfc37ad20d4a..a842fd847684 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -334,7 +334,7 @@ static int prepare_elf64_headers(struct crash_mem *cmem,
> int kernel_map,
> Elf64_Ehdr *ehdr;
> Elf64_Phdr *phdr;
> unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
> - unsigned char *buf, *bufp;
> + unsigned char *buf;
> unsigned int cpu, i;
> unsigned long long notes_addr;
> unsigned long mstart, mend;
> @@ -359,9 +359,8 @@ static int prepare_elf64_headers(struct crash_mem *cmem,
> int kernel_map,
> if (!buf)
> return -ENOMEM;
>
> - bufp = buf;
> - ehdr = (Elf64_Ehdr *)bufp;
> - bufp += sizeof(Elf64_Ehdr);
> + ehdr = (Elf64_Ehdr *)buf;
> + phdr = (Elf64_Phdr *)(ehdr + 1);
phdr should start with ehdr + sizeof(Elf64_Ehdr);
> memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
> ehdr->e_ident[EI_CLASS] = ELFCLASS64;
> ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
> @@ -377,33 +376,30 @@ static int prepare_elf64_headers(struct crash_mem
> *cmem, int kernel_map,
>
> /* Prepare one phdr of type PT_NOTE for each present cpu */
> for_each_present_cpu(cpu) {
> - phdr = (Elf64_Phdr *)bufp;
> - bufp += sizeof(Elf64_Phdr);
> phdr->p_type = PT_NOTE;
> notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
> phdr->p_offset = phdr->p_paddr = notes_addr;
> phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
> (ehdr->e_phnum)++;
> + phdr++;
> }
>
> /* Prepare one PT_NOTE header for vmcoreinfo */
> - phdr = (Elf64_Phdr *)bufp;
> - bufp += sizeof(Elf64_Phdr);
> phdr->p_type = PT_NOTE;
> phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
> phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
> (ehdr->e_phnum)++;
> + phdr++;
>
> /* Prepare PT_LOAD type program header for kernel text region */
> if (kernel_map) {
> - phdr = (Elf64_Phdr *)bufp;
> - bufp += sizeof(Elf64_Phdr);
> phdr->p_type = PT_LOAD;
> phdr->p_flags = PF_R|PF_W|PF_X;
> phdr->p_vaddr = (Elf64_Addr)_text;
> phdr->p_filesz = phdr->p_memsz = _end - _text;
> phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
> - (ehdr->e_phnum)++;
> + ehdr->e_phnum++;
> + phdr++;
> }
>
> /* Go through all the ranges in cmem->ranges[] and prepare phdr */
> --
> 2.16.2
>
Thanks
Dave
