user/sven/linux.git/scripts/mod/modpost.c, branch v4.6.1

powerpc: Simplify module TOC handling

2016-01-21T03:10:56Z

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 Signed-off-by: Michael Ellerman

scripts: [modpost] add new sections to white list

2015-10-26T10:08:43Z

In our ARC toolchain the default linker script includes special sections used for code and data located in special fast memory. To avoid warnings we add these sections i.e. .cmem* and .fmt_slot* to white list. Signed-off-by: Noam Camus Cc: Rusty Russell Cc: Quentin Casasnovas Signed-off-by: Rusty Russell

modpost: Add flag -E for making section mismatches fatal

2015-10-06T00:16:21Z

The section mismatch warning can be easy to miss during the kernel build process. Allow it to be marked as fatal to be easily caught and prevent bugs from slipping in. Setting CONFIG_SECTION_MISMATCH_WARN_ONLY=y causes these warnings to be non-fatal, since there are a number of section mismatches when using allmodconfig on some architectures, and we do not want to break these builds by default. Signed-off-by: Nicolas Boichat Change-Id: Ic346706e3297c9f0d790e3552aa94e5cff9897a6 Signed-off-by: Rusty Russell

modpost: abort if a module symbol is too long

2015-08-08T10:22:08Z

Module symbols have a limited length, but currently the build system allows the build finishing even if the driver code contains a too long symbol name, which eventually overflows the modversion_info[] item. The compiler may catch at compiling *.mod.c like CC xxx.mod.o xxx.mod.c:18:16: warning: initializer-string for array of chars is too long but it's merely a warning. This patch adds the check of the symbol length in modpost and stops the build properly. Currently MODULE_NAME_LEN is defined in modpost.c instead of referring to the definition in kernel header because including linux/module.h is messy and we must cover cross-compilation. Signed-off-by: Takashi Iwai Signed-off-by: Rusty Russell

modpost: work correctly with tile coldtext sections

2015-07-08T22:53:49Z

The tilegx and tilepro compilers use .coldtext for their unlikely executed text section name, so an __attribute__((cold)) function will (when compiled with higher optimization levels) land in the .coldtext section. Modify modpost to add .coldtext to the set of OTHER_TEXT_SECTIONS so we don't get warnings about referencing such a section in an __ex_table block, and then also modify arch/tile/lib/memcpy_user_64.c so that it uses plain ".coldtext" instead of ".coldtext.memcpy". The latter naming is a relic of an earlier use of -ffunction-sections, which we no longer use by default. Signed-off-by: Chris Metcalf Acked-by: Rusty Russell

modpost: don't emit section mismatch warnings for compiler optimizations

2015-04-22T08:01:34Z

Currently an allyesconfig build [gcc-4.9.1] can generate the following: WARNING: vmlinux.o(.text.unlikely+0x3864): Section mismatch in reference from the function cpumask_empty.constprop.3() to the variable .init.data:nmi_ipi_mask which comes from the cpumask_empty usage in arch/x86/kernel/nmi_selftest.c. Normally we would not see a symbol entry for cpumask_empty since it is: static inline bool cpumask_empty(const struct cpumask *srcp) however in this case, the variant of the symbol gets emitted when GCC does constant propagation optimization. Fix things up so that any locally optimized constprop variants don't warn when accessing variables that live in the __init sections. Signed-off-by: Paul Gortmaker Signed-off-by: Rusty Russell

modpost: expand pattern matching to support substring matches

2015-04-22T08:01:33Z

Currently the match() function supports a leading * to match any prefix and a trailing * to match any suffix. However there currently is not a combination of both that can be used to target matches of whole families of functions that share a common substring. Here we expand the *foo and foo* match to also support *foo* with the goal of targeting compiler generated symbol names that contain strings like ".constprop." and ".isra." Signed-off-by: Paul Gortmaker Signed-off-by: Rusty Russell

modpost: do not try to match the SHT_NUL section.

2015-04-22T08:01:33Z

Trying to match the SHT_NUL section isn't useful and causes build failures on parisc and mn10300 since the addition of section strict white-listing and __ex_table sanitizing. Signed-off-by: Quentin Casasnovas Reported-by: Guenter Roeck Fixes: 050e57fd5936 ("modpost: add strict white-listing when referencing....") Fixes: 52dc0595d540 ("modpost: handle relocations mismatch in __ex_table.") Tested-by: Guenter Roeck Signed-off-by: Rusty Russell

modpost: fix extable entry size calculation.

2015-04-22T08:01:32Z

As Guenter pointed out, we were never really calculating the extable entry size because the pointer arithmetic was simply wrong. We want to check we're handling the second relocation in __ex_table to infer an entry size, but we were using (void*) pointers instead of Elf_Rel[a]* ones. This fixes the problem by moving that check in the caller (since we can deal with different types of relocations) and add is_second_extable_reloc() to make the whole thing more readable. Signed-off-by: Quentin Casasnovas Reported-by: Guenter Roeck CC: Rusty Russell Signed-off-by: Rusty Russell

modpost: fix inverted logic in is_extable_fault_address().

2015-04-22T08:01:31Z

As Guenter pointed out, we want to assert that extable_entry_size has been discovered and not the other way around. Moreover, this sanity check is only valid when we're not dealing with the first relocation in __ex_table, since we have not discovered the extable entry size at that point. This was leading to a divide-by-zero on some architectures and make the build fail. Signed-off-by: Quentin Casasnovas Reported-by: Guenter Roeck CC: Rusty Russell Signed-off-by: Rusty Russell