From 620f697cc27a6d9b09268f47cd13620488ec67af Mon Sep 17 00:00:00 2001
From: Philipp Rudo <prudo@linux.vnet.ibm.com>
Date: Fri, 13 Apr 2018 15:36:35 -0700
Subject: [PATCH] kernel/kexec_file.c: remove unneeded variables in
kexec_purgatory_setup_sechdrs
The main loop currently uses quite a lot of variables to update the
section headers. Some of them are unnecessary. So clean them up a
little.
Link: http://lkml.kernel.org/r/20180321112751.22196-9-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
kernel/kexec_file.c | 34 ++++++++++++----------------------
1 file changed, 12 insertions(+), 22 deletions(-)
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 6f0ec9f2e5c14..7b63de8a89b65 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -785,12 +785,8 @@ static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
struct kexec_buf *kbuf)
{
- unsigned long curr_load_addr;
- unsigned long load_addr;
unsigned long bss_addr;
unsigned long offset;
- unsigned char *buf_addr;
- unsigned char *src;
Elf_Shdr *sechdrs;
int i;
@@ -823,20 +819,18 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
sechdrs[i].sh_offset;
}
- /* Load SHF_ALLOC sections */
- buf_addr = kbuf->buffer;
- load_addr = curr_load_addr = kbuf->mem;
- bss_addr = load_addr + kbuf->bufsz;
+ offset = 0;
+ bss_addr = kbuf->mem + kbuf->bufsz;
kbuf->image->start = pi->ehdr->e_entry;
for (i = 0; i < pi->ehdr->e_shnum; i++) {
unsigned long align;
+ void *src, *dst;
if (!(sechdrs[i].sh_flags & SHF_ALLOC))
continue;
align = sechdrs[i].sh_addralign;
-
if (sechdrs[i].sh_type == SHT_NOBITS) {
bss_addr = ALIGN(bss_addr, align);
sechdrs[i].sh_addr = bss_addr;
@@ -844,31 +838,27 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
continue;
}
- curr_load_addr = ALIGN(curr_load_addr, align);
- offset = curr_load_addr - load_addr;
- /* We already modifed ->sh_offset to keep src addr */
- src = (char *)sechdrs[i].sh_offset;
- memcpy(buf_addr + offset, src, sechdrs[i].sh_size);
-
+ offset = ALIGN(offset, align);
if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
pi->ehdr->e_entry < (sechdrs[i].sh_addr
+ sechdrs[i].sh_size)) {
kbuf->image->start -= sechdrs[i].sh_addr;
- kbuf->image->start += curr_load_addr;
+ kbuf->image->start += kbuf->mem + offset;
}
- /* Store load address and source address of section */
- sechdrs[i].sh_addr = curr_load_addr;
+ src = (void *)sechdrs[i].sh_offset;
+ dst = pi->purgatory_buf + offset;
+ memcpy(dst, src, sechdrs[i].sh_size);
+
+ sechdrs[i].sh_addr = kbuf->mem + offset;
/*
* This section got copied to temporary buffer. Update
* ->sh_offset accordingly.
*/
- sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset);
-
- /* Advance to the next address */
- curr_load_addr += sechdrs[i].sh_size;
+ sechdrs[i].sh_offset = (unsigned long)dst;
+ offset += sechdrs[i].sh_size;
}
return 0;
--
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