[PATCH v2 6/7] x86: kexec_file: clean up prepare_elf64_headers()

From: AKASHI Takahiro
Date: Tue Mar 06 2018 - 05:23:51 EST


removing bufp variable in prepare_elf64_headers() makes the code simpler
and more understandable.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
---
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 0f20a6330bd6..24de3f13f40c 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -336,7 +336,7 @@ static int prepare_elf64_headers(struct crash_mem *cmem, bool 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;
@@ -361,9 +361,8 @@ static int prepare_elf64_headers(struct crash_mem *cmem, bool 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);
memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
ehdr->e_ident[EI_CLASS] = ELFCLASS64;
ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
@@ -379,33 +378,30 @@ static int prepare_elf64_headers(struct crash_mem *cmem, bool 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