linux-stable.git/scripts/mod/modpost.c, branch v3.2.102

module/retpoline: Warn about missing retpoline in module

2018-03-19T18:58:35+00:00

commit caf7501a1b4ec964190f31f9c3f163de252273b8 upstream.

There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.

To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.

If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.

[ tglx: Massaged changelog ]

Signed-off-by: Andi Kleen 
Signed-off-by: Thomas Gleixner 
Cc: David Woodhouse 
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
Signed-off-by: Ben Hutchings

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

2018-03-19T18:58:24+00:00

commit 4a3893d069b788f3570c19c12d9e986e8e15870f upstream.

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 
[bwh: Backported to 3.2: Add definitions of {OTHER,ALL}_TEXT_SECTIONS]
Signed-off-by: Ben Hutchings

modpost: reduce visibility of symbols and constify r/o arrays

2018-03-19T18:58:24+00:00

commit 7a3ee7538598e0d60e6aa87dcf34a4e8a0adebc2 upstream.

Internally used symbols of modpost don't need to be externally visible;
make them static. Also constify the string arrays so they resist in the
r/o section instead of being runtime writable.

Those changes lead to a small size reduction as can be seen below:

   text    data     bss     dec     hex filename
  51381    2640   12416   66437   10385 scripts/mod/modpost.old
  51765    2224   12416   66405   10365 scripts/mod/modpost.new

Signed-off-by: Mathias Krause 
Signed-off-by: Rusty Russell 
Signed-off-by: Ben Hutchings

powerpc: Add vr save/restore functions

2014-06-09T12:28:54+00:00

commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

modpost: Fix modpost license checking of vmlinux.o

2012-04-13T15:33:49+00:00

commit 258f742635360175564e9470eb060ff4d4b984e7 upstream.

Commit f02e8a6596b7 ("module: Sort exported symbols") sorts symbols
placing each of them in its own elf section.  This sorting and merging
into the canonical sections are done by the linker.

Unfortunately modpost to generate Module.symvers file parses vmlinux.o
(which is not linked yet) and all modules object files (which aren't
linked yet).  These aren't sanitized by the linker yet.  That breaks
modpost that can't detect license properly for modules.

This patch makes modpost aware of the new exported symbols structure.

[ This above is a slightly corrected version of the explanation of the
  problem, copied from commit 62a2635610db ("modpost: Fix modpost's
  license checking V3").  That commit fixed the problem for module
  object files, but not for vmlinux.o.  This patch fixes modpost for
  vmlinux.o. ]

Signed-off-by: Frank Rowand 
Signed-off-by: Alessio Igor Bogani 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

modpost: fix ALL_INIT_DATA_SECTIONS

2012-04-13T15:33:46+00:00

commit 9aaf440f8fabcebf9ea79a62ccf4c212e6544b49 upstream.

This was lacking a comma between two supposed to be separate strings.

Signed-off-by: Jan Beulich 
Signed-off-by: Michal Marek 
Signed-off-by: Greg Kroah-Hartman

module,bug: Add TAINT_OOT_MODULE flag for modules not built in-tree

2011-11-06T21:24:42+00:00

Use of the GPL or a compatible licence doesn't necessarily make the code
any good.  We already consider staging modules to be suspect, and this
should also be true for out-of-tree modules which may receive very
little review.

Signed-off-by: Ben Hutchings 
Reviewed-by: Dave Jones 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Rusty Russell  (patched oops-tracing.txt)

modpost: Fix modpost's license checking V3

2011-07-24T12:36:05+00:00

The commit f02e8a6 sorts symbols placing each of them in its own elf section.
The sorting and merging into the canonical sections are done by the linker.
Unfortunately modpost to generate Module.symvers file parses vmlinux
(already linked) and all modules object files (which aren't linked yet).
These aren't sanitized by the linker yet. That breaks modpost that can't
detect license properly for modules. This patch makes modpost aware of
the new exported symbols structure.

Thanks to Arnaud Lacombe  and Anders Kaseorg
 for providing useful suggestions about code.

This work was supported by a hardware donation from the CE Linux Forum.

Reported-by: Jan Beulich 
Signed-off-by: Alessio Igor Bogani 
Signed-off-by: Rusty Russell

modpost: Update 64k section support for binutils 2.18.50

2011-05-19T07:25:28+00:00

Binutils 2.18.50 made a backwards-incompatible change in the way it
writes ELF objects with over 65280 sections, to improve conformance
with the ELF specification and interoperability with other ELF tools.
Specifically, it no longer adds 256 to section indices SHN_LORESERVE
and higher to skip over the reserved range SHN_LORESERVE through
SHN_HIRESERVE; those values are only considered special in the
st_shndx field, and not in other places where section indices are
stored.  See:

http://sourceware.org/bugzilla/show_bug.cgi?id=5900
http://groups.google.com/group/generic-abi/browse_thread/thread/e8bb63714b072e67/6c63738f12cc8a17

Signed-off-by: Anders Kaseorg 
Signed-off-by: Rusty Russell

modpost: fix trailing comma

2011-03-17T12:02:31+00:00

Consolidate locations that print a section whitelist into
calls to print_section_list().

Fix print_section_list() so that it does not print a trailing
comma & space:

If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

becomes:
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Signed-off-by: Randy Dunlap 
Signed-off-by: Michal Marek