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authorPhilipp Rudo <prudo@linux.vnet.ibm.com>2018-04-13 15:36:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-13 17:10:28 -0700
commitf1b1cca39650c9c1dbe26140946a518953f66771 (patch)
treeec9b5b836fa82cd7956f01ec4f40ad66d51dc165
parent930457057abe4e6d57433dea75e97e0e39fd0ab6 (diff)
downloadlinux-stericsson-f1b1cca39650c9c1dbe26140946a518953f66771.tar.gz
kernel/kexec_file.c: remove unneeded for-loop in kexec_purgatory_setup_sechdrs
To update the entry point there is an extra loop over all section headers although this can be done in the main loop. So move it there and eliminate the extra loop and variable to store the 'entry section index'. Also, in the main loop, move the usual case, i.e. non-bss section, out of the extra if-block. Link: http://lkml.kernel.org/r/20180321112751.22196-8-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.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: 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>
-rw-r--r--kernel/kexec_file.c76
1 files changed, 30 insertions, 46 deletions
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 878b97bd3067..6f0ec9f2e5c1 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -792,7 +792,6 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
unsigned char *buf_addr;
unsigned char *src;
Elf_Shdr *sechdrs;
- int entry_sidx = -1;
int i;
sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr));
@@ -824,32 +823,11 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
sechdrs[i].sh_offset;
}
- /*
- * Identify entry point section and make entry relative to section
- * start.
- */
- kbuf->image->start = pi->ehdr->e_entry;
- for (i = 0; i < pi->ehdr->e_shnum; i++) {
- if (!(sechdrs[i].sh_flags & SHF_ALLOC))
- continue;
-
- if (!(sechdrs[i].sh_flags & SHF_EXECINSTR))
- continue;
-
- /* Make entry section relative */
- if (sechdrs[i].sh_addr <= pi->ehdr->e_entry &&
- ((sechdrs[i].sh_addr + sechdrs[i].sh_size) >
- pi->ehdr->e_entry)) {
- entry_sidx = i;
- kbuf->image->start -= sechdrs[i].sh_addr;
- break;
- }
- }
-
/* Load SHF_ALLOC sections */
buf_addr = kbuf->buffer;
load_addr = curr_load_addr = kbuf->mem;
bss_addr = load_addr + kbuf->bufsz;
+ kbuf->image->start = pi->ehdr->e_entry;
for (i = 0; i < pi->ehdr->e_shnum; i++) {
unsigned long align;
@@ -858,34 +836,40 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
continue;
align = sechdrs[i].sh_addralign;
- if (sechdrs[i].sh_type != SHT_NOBITS) {
- 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);
-
- /* Store load address and source address of section */
- sechdrs[i].sh_addr = curr_load_addr;
-
- /*
- * 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;
- } else {
+
+ if (sechdrs[i].sh_type == SHT_NOBITS) {
bss_addr = ALIGN(bss_addr, align);
sechdrs[i].sh_addr = bss_addr;
bss_addr += sechdrs[i].sh_size;
+ 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);
+
+ 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;
}
- }
- /* Update entry point based on load address of text section */
- if (entry_sidx >= 0)
- kbuf->image->start += sechdrs[entry_sidx].sh_addr;
+ /* Store load address and source address of section */
+ sechdrs[i].sh_addr = curr_load_addr;
+
+ /*
+ * 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;
+ }
return 0;
}