linux/arch/powerpc
Alan Modra c153693d7e powerpc: Simplify module TOC handling
PowerPC64 uses the symbol .TOC. much as other targets use
_GLOBAL_OFFSET_TABLE_. It identifies the value of the GOT pointer (or in
powerpc parlance, the TOC pointer). Global offset tables are generally
local to an executable or shared library, or in the kernel, module. Thus
it does not make sense for a module to resolve a relocation against
.TOC. to the kernel's .TOC. value. A module has its own .TOC., and
indeed the powerpc64 module relocation processing ignores the kernel
value of .TOC. and instead calculates a module-local value.

This patch removes code involved in exporting the kernel .TOC., tweaks
modpost to ignore an undefined .TOC., and the module loader to twiddle
the section symbol so that .TOC. isn't seen as undefined.

Note that if the kernel was compiled with -msingle-pic-base then ELFv2
would not have function global entry code setting up r2. In that case
the module call stubs would need to be modified to set up r2 using the
kernel .TOC. value, requiring some of this code to be reinstated.

mpe: Furthermore a change in binutils master (not yet released) causes
the current way we handle the TOC to no longer work when building with
MODVERSIONS=y and RELOCATABLE=n. The symptom is that modules can not be
loaded due to there being no version found for TOC.

Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Alan Modra <amodra@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-21 14:10:56 +11:00
..
boot powerpc updates for 4.5 2016-01-15 13:18:47 -08:00
configs powerpc/85xx: Enable TWR_P102x in mpc85xx_basic_defconfig 2015-12-22 18:23:21 -06:00
crypto powerpc: Create disable_kernel_{fp,altivec,vsx,spe}() 2015-12-01 13:52:25 +11:00
include powerpc: Wire up copy_file_range() syscall 2016-01-21 14:10:55 +11:00
kernel powerpc: Simplify module TOC handling 2016-01-21 14:10:56 +11:00
kvm kvm: rename pfn_t to kvm_pfn_t 2016-01-15 17:56:32 -08:00
lib powerpc: Create disable_kernel_{fp,altivec,vsx,spe}() 2015-12-01 13:52:25 +11:00
math-emu powerpc: Correct emulated mtfsf instruction 2014-04-07 10:33:11 +10:00
mm powerpc, thp: remove infrastructure for handling splitting PMDs 2016-01-15 17:56:32 -08:00
net net: filter: make JITs zero A for SKF_AD_ALU_XOR_X 2016-01-06 00:43:52 -05:00
oprofile powerpc: Remove mtmsrd(), use existing mtmsr() 2015-07-13 15:47:28 +10:00
perf powerpc updates for 4.4 2015-11-05 23:38:43 -08:00
platforms powerpc updates for 4.5 2016-01-15 13:18:47 -08:00
sysdev mm, dax, pmem: introduce pfn_t 2016-01-15 17:56:32 -08:00
xmon powerpc/xmon: Use rtas_call_unlocked() in xmon 2015-12-17 22:40:55 +11:00
Kconfig Kconfig: remove HAVE_LATENCYTOP_SUPPORT 2016-01-16 11:17:23 -08:00
Kconfig.debug powerpc updates for 4.5 2016-01-15 13:18:47 -08:00
Makefile powerpc/cell: Drop CONFIG_TUNE_CELL in favour of CONFIG_CELL_CPU 2015-10-19 19:51:18 +11:00
relocs_check.sh powerpc: Convert relocs_check to a shell script using grep 2015-03-23 14:47:39 +11:00