linux-stable/arch
Dave Martin 9a00318ead ARM: 6963/1: Thumb-2: Relax relocation requirements for non-function symbols
The "Thumb bit" of a symbol is only really meaningful for function
symbols (STT_FUNC).

However, sometimes a branch is relocated against a non-function
symbol; for example, PC-relative branches to anonymous assembler
local symbols are typically fixed up against the start-of-section
symbol, which is not a function symbol.  Some inline assembler
generates references of this type, such as fixup code generated by
macros in <asm/uaccess.h>.

The existing relocation code for R_ARM_THM_CALL/R_ARM_THM_JUMP24
interprets this case as an error, because the target symbol appears
to be an ARM symbol; but this is really not the case, since the
target symbol is just a base in these cases.  The addend defines
the precise offset to the target location, but since the addend is
encoded in a non-interworking Thumb branch instruction, there is no
explicit Thumb bit in the addend.  Because these instructions never
interwork, the implied Thumb bit in the addend is 1, and the
destination is Thumb by definition.

This patch removes the extraneous Thumb bit check for non-function
symbols, enabling modules containing the affected relocation types
to be loaded.  No modification to the actual relocation code is
required, since this code does not take bit[0] of the
location->destination offset into account in any case.

Function symbols are always checked for interworking conflicts, as
before.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-17 11:25:04 +01:00
..
alpha alpha: fix several security issues 2011-06-15 20:04:02 -07:00
arm ARM: 6963/1: Thumb-2: Relax relocation requirements for non-function symbols 2011-06-17 11:25:04 +01:00
avr32 rtc: fix build warnings in defconfigs 2011-06-15 20:04:02 -07:00
blackfin rtc: fix build warnings in defconfigs 2011-06-15 20:04:02 -07:00
cris Merge branch 'setns' 2011-05-28 10:51:01 -07:00
frv Merge branch 'setns' 2011-05-28 10:51:01 -07:00
h8300 Merge branch 'setns' 2011-05-28 10:51:01 -07:00
ia64 [IA64] wire up sendmmsg() syscall for Itanium 2011-05-31 10:09:24 -07:00
m32r Merge branch 'setns' 2011-05-28 10:51:01 -07:00
m68k m68k: use kernel processor defines for conditional optimizations 2011-06-14 11:42:29 +10:00
microblaze Merge branch 'setns' 2011-05-28 10:51:01 -07:00
mips rtc: fix build warnings in defconfigs 2011-06-15 20:04:02 -07:00
mn10300 MN10300: Add missing _sdata declaration 2011-06-07 19:03:53 -07:00
parisc Merge branch 'setns' 2011-05-28 10:51:01 -07:00
powerpc rtc: fix build warnings in defconfigs 2011-06-15 20:04:02 -07:00
s390 [S390] fix kvm defines for 31 bit compile 2011-06-06 14:14:56 +02:00
score arch: remove CONFIG_GENERIC_FIND_{NEXT_BIT,BIT_LE,LAST_BIT} 2011-05-26 17:12:38 -07:00
sh Merge branch 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x 2011-06-16 09:46:24 -07:00
sparc sparc32, leon: bugfix in LEON SMP interrupt init 2011-06-09 16:12:34 -07:00
tile Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2011-05-29 11:29:28 -07:00
um arch: remove CONFIG_GENERIC_FIND_{NEXT_BIT,BIT_LE,LAST_BIT} 2011-05-26 17:12:38 -07:00
unicore32 unicore32: using generic-y format for one line asm-generic files 2011-06-09 16:29:52 +08:00
x86 x86 idle: APM requires pm_idle/default_idle unconditionally when a module 2011-06-14 13:42:20 -07:00
xtensa Merge branch 'setns' 2011-05-28 10:51:01 -07:00
.gitignore
Kconfig mm, powerpc: move the RCU page-table freeing into generic code 2011-05-25 08:39:16 -07:00