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  1. 27 Dec, 2010 1 commit
    • Olof Johansson's avatar
      modpost: Fix address calculation in reloc_location() · 731ece41
      Olof Johansson authored 
      This patch fixes a segfault in modpost that is observed when the gold
linker is used to link the input objects.

The problem is that reloc_location (modpost.c) is computing the
address of the relocation target incorrectly. Here, elf->hdr points
to the beginning of the ELF file in memory, sechdr points to the
relocation section header, section is the index of the section
being relocated, and sechdrs[section].sh_offset would be the offset
of that section, relative to the beginning of the ELF file. Adding
elf->hdr + sechdrs[section].sh_offset gives you the address of the
beginning of the section, and adding r->r_offset to that gives you the
address of the location to be relocated. You do not need to subtract
sechdrs[section].sh_addr from that -- the result of this is an address
outside the file, and causes the segfault when addend_386_rel tries to
dereference it.

This bug is not observed when GNU ld is used to link the inputs. The
object file ubuntu/omnibook/omnibook.o is the result of an ld -r of
several other files.  When GNU ld does an ld -r, it sets the vaddr
field for each section to 0, but gold lays out the section addresses
sequentially instead:

Section Headers:
 [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
 [ 0]                   NULL            00000000 000000 000000 00      0   0  0
 [ 1] .text             PROGBITS        00000000 000034 004794 00  AX  0   0  4
 [ 2] .data             PROGBITS        0000b9d0 0047c8 0009c0 00  WA  0   0  4
 [ 3] .bss              NOBITS          000162f8 005188 00013c 00  WA  0   0  4
 [ 4] .rodata.str1.1    PROGBITS        00004f2d 0052c4 001b1a 01 AMS  0   0  1
 [ 5] .init.text        PROGBITS        00004794 006dde 0005fa 00  AX  0   0  1
 [ 6] .exit.text        PROGBITS        00004d8e 0073d8 00018a 00  AX  0   0  1
  ...

So the bug in the tool remained undiscovered because the section's vaddr
always happened to be 0.
Signed-off-by: default avatarRaymes Khoury <raymes@google.com>
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
      731ece41
  3. 22 Dec, 2010 1 commit
  5. 20 Dec, 2010 1 commit
  7. 16 Dec, 2010 1 commit
  9. 14 Dec, 2010 5 commits
  11. 02 Dec, 2010 1 commit
    • Thomas Chou's avatar
      gen_init_cpio: remove leading `/' from file names · 43f901fb
      Thomas Chou authored 
      When we extracted the generated cpio archive using "cpio -id" command,
it complained,

cpio: Removing leading `/' from member names
var/run
cpio: Removing leading `/' from member names
var/lib
cpio: Removing leading `/' from member names
var/lib/misc

It is worse with the latest "cpio" or "pax", which tries to overwrite
the host file system with the leading '/'.

So the leading '/' of file names should be removed. This is consistent
with the initramfs come with major distributions such as Fedora or
Debian, etc.
Signed-off-by: default avatarThomas Chou <thomas@wytron.com.tw>
Acked-by: Mike Frysinger<vapier@gentoo.org>
Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
      43f901fb
  13. 25 Nov, 2010 1 commit
  15. 11 Nov, 2010 1 commit
    • Eric Dumazet's avatar
      fixdep: use hash table instead of a single array · 8af27e1d
      Eric Dumazet authored 
      I noticed fixdep uses ~2% of cpu time in kernel build, in function
use_config()

fixdep spends a lot of cpu cycles in linear searches in its internal
string array. With about 400 stored strings per dep file, this begins to
be noticeable.

Convert fixdep to use a hash table.

kbuild results on my x86_64 allmodconfig

Before patch :

real	10m30.414s
user	61m51.456s
sys	8m28.200s

real	10m12.334s
user	61m50.236s
sys	8m30.448s

real	10m42.947s
user	61m50.028s
sys	8m32.380s

After:

real	10m8.180s
user	61m22.506s
sys	8m32.384s

real	10m35.039s
user	61m21.654s
sys	8m32.212s

real	10m14.487s
user	61m23.498s
sys	8m32.312s
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
      8af27e1d
  17. 01 Nov, 2010 10 commits
  19. 31 Oct, 2010 14 commits
  21. 30 Oct, 2010 4 commits
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