x86: kexec_file: clean up prepare_elf64_headers()

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

Link: http://lkml.kernel.org/r/20180306102303.9063-7-takahiro.akashi@linaro.org
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Dave Young <dyoung@redhat.com>
Tested-by: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 8175c0c205e6e63a148b103964da74953d489cc1..229b8ecf8428a1c611a815b0401a5813bf339222 100644 (file)
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -337,7 +337,7 @@ 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;
@@ -362,9 +362,8 @@ 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;
@@ -380,33 +379,30 @@ 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 */