linux-stable.git/scripts/mod, branch linux-4.1.y

powerpc: Simplify module TOC handling

2018-03-01T03:09:48+00:00

[ Upstream commit c153693d7eb9eeb28478aa2deaaf0b4e7b5ff5e9 ]

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 
Signed-off-by: Sasha Levin

of: fix autoloading due to broken modalias with no 'compatible'

2016-06-18T15:59:23+00:00

[ Upstream commit b3c0a4dab7e35a9b6d69c0415641d2280fdefb2b ]

Because of an improper dereference, a stray 'C' character was output to
the modalias when no 'compatible' was specified. This is the case for
some old PowerMac drivers which only set the 'name' property. Fix it to
let them match again.

Reported-by: Mathieu Malaterre 
Signed-off-by: Wolfram Sang 
Tested-by: Mathieu Malaterre 
Cc: Philipp Zabel 
Cc: Andreas Schwab 
Fixes: 6543becf26fff6 ("mod/file2alias: make modalias generation safe for cross compiling")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2015-04-22T16:49:24+00:00

Pull module updates from Rusty Russell:
 "Quentin opened a can of worms by adding extable entry checking to
  modpost, but most architectures seem fixed now.  Thanks to all
  involved.

  Last minute rebase because I noticed a "[PATCH]" had snuck into a
  commit message somehow"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modpost: don't emit section mismatch warnings for compiler optimizations
  modpost: expand pattern matching to support substring matches
  modpost: do not try to match the SHT_NUL section.
  modpost: fix extable entry size calculation.
  modpost: fix inverted logic in is_extable_fault_address().
  modpost: handle -ffunction-sections
  modpost: Whitelist .text.fixup and .exception.text
  params: handle quotes properly for values not of form foo="bar".
  modpost: document the use of struct section_check.
  modpost: handle relocations mismatch in __ex_table.
  scripts: add check_extable.sh script.
  modpost: mismatch_handler: retrieve tosym information only when needed.
  modpost: factorize symbol pretty print in get_pretty_name().
  modpost: add handler function pointer to sectioncheck.
  modpost: add .sched.text and .kprobes.text to the TEXT_SECTIONS list.
  modpost: add strict white-listing when referencing sections.
  module: do not print allocation-fail warning on bogus user buffer size
  kernel/module.c: fix typos in message about unused symbols

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

2015-04-22T08:01:34+00:00

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

2015-04-22T08:01:33+00:00

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.

2015-04-22T08:01:33+00:00

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.

2015-04-22T08:01:32+00:00

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().

2015-04-22T08:01:31+00:00

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

modpost: handle -ffunction-sections

2015-04-22T08:01:31+00:00

52dc0595d540 introduced OTHER_TEXT_SECTIONS for identifying what
sections could validly have __ex_table entries.  Unfortunately, it
wasn't tested with -ffunction-sections, which some architectures
use.

Reported-by: kbuild test robot 
Cc: Quentin Casasnovas 
Signed-off-by: Rusty Russell

modpost: Whitelist .text.fixup and .exception.text

2015-04-22T08:01:20+00:00

32-bit and 64-bit ARM use these sections to store executable code, so
they must be whitelisted in modpost's table of valid text sections.

Signed-off-by: Thierry Reding 
Signed-off-by: Rusty Russell