linux-stable.git/arch/x86/boot/string.c, branch v5.2

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497

2019-06-19T15:09:53+00:00

Based on 1 normalized pattern(s):

  this file is part of the linux kernel and is made available under
  the terms of the gnu general public license version 2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 28 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Allison Randal 
Reviewed-by: Kate Stewart 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.534229504@linutronix.de
Signed-off-by: Greg Kroah-Hartman

x86/boot: Restrict header scope to make Clang happy

2019-03-21T11:24:38+00:00

The inclusion of  was causing issue as the definition of
__arch_hweight64 from arch/x86/include/asm/arch_hweight.h eventually gets
included. The definition is problematic when compiled with -m16 (all code
in arch/x86/boot/ is) as the "D" inline assembly constraint is rejected
by both compilers when passed an argument of type long long (regardless
of signedness, anything smaller is fine).

Because GCC performs inlining before semantic analysis, and
__arch_hweight64 is dead in this translation unit, GCC does not report
any issues at compile time.  Clang does the semantic analysis in the
front end, before inlining (run in the middle) can determine the code is
dead. I consider this another case of PR33587, which I think we can do
more work to solve.

It turns out that arch/x86/boot/string.c doesn't actually need
linux/kernel.h, simply linux/limits.h and linux/compiler.h.

Suggested-by: Stephen Rothwell 
Signed-off-by: Nick Desaulniers 
Signed-off-by: Thomas Gleixner 
Tested-by: Nathan Chancellor 
Reviewed-by: Nathan Chancellor 
Cc: bp@alien8.de
Cc: niravd@google.com
Cc: "H. Peter Anvin" 
Cc: Chao Fan 
Cc: Uros Bizjak 
Link: https://bugs.llvm.org/show_bug.cgi?id=33587
Link: https://github.com/ClangBuiltLinux/linux/issues/347
Link: https://lkml.kernel.org/r/20190314221458.83047-1-ndesaulniers@google.com

x86/boot: Copy kstrtoull() to boot/string.c

2019-02-01T10:52:54+00:00

Copy kstrtoull() and the other necessary functions from lib/kstrtox.c
to boot/string.c so that code in boot/ can use kstrtoull() and the old
simple_strtoull() can gradually be phased out.

Using div_u64() from math64.h directly will cause the dividend to be
handled as a 64-bit value and cause the infamous __divdi3 linker error
due to gcc trying to use its library function for the 64-bit division.

Therefore, separate the dividend into an upper and lower part.

 [ bp: Rewrite commit message. ]

Signed-off-by: Chao Fan 
Signed-off-by: Borislav Petkov 
Cc: bhe@redhat.com
Cc: caoj.fnst@cn.fujitsu.com
Cc: "H. Peter Anvin" 
Cc: indou.takao@jp.fujitsu.com
Cc: Ingo Molnar 
Cc: kasong@redhat.com
Cc: Kees Cook 
Cc: msys.mizuma@gmail.com
Cc: Thomas Gleixner 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20190123110850.12433-2-fanc.fnst@cn.fujitsu.com

x86/boot: Use CC_SET()/CC_OUT() instead of open coding it

2018-08-02T12:30:42+00:00

Remove open-coded uses of set instructions with CC_SET()/CC_OUT().

Signed-off-by: Uros Bizjak 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20180629142844.15200-1-ubizjak@gmail.com

x86/boot: #undef memcpy() et al in string.c

2017-07-25T09:13:55+00:00

undef memcpy() and friends in boot/string.c so that the functions
defined here will have the correct names, otherwise we end up
up trying to redefine __builtin_memcpy() etc.

Surprisingly, GCC allows this (and, helpfully, discards the
__builtin_ prefix from the function name when compiling it),
but clang does not.

Adding these #undef's appears to preserve what I assume was
the original intent of the code.

Signed-off-by: Michael Davidson 
Signed-off-by: Matthias Kaehlcke 
Acked-by: H. Peter Anvin 
Cc: Arnd Bergmann 
Cc: Bernhard.Rosenkranzer@linaro.org
Cc: Greg Hackmann 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20170724235155.79255-1-mka@chromium.org
Signed-off-by: Ingo Molnar

x86/KASLR: Parse all 'memmap=' boot option entries

2017-05-24T07:50:27+00:00

In commit:

  f28442497b5c ("x86/boot: Fix KASLR and memmap= collision")

... the memmap= option is parsed so that KASLR can avoid those reserved
regions. It uses cmdline_find_option() to get the value if memmap=
is specified, however the problem is that cmdline_find_option() can only
find the last entry if multiple memmap entries are provided. This
is not correct.

Address this by checking each command line token for a "memmap=" match
and parse each instance instead of using cmdline_find_option().

Signed-off-by: Baoquan He 
Acked-by: Kees Cook 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: dan.j.williams@intel.com
Cc: douly.fnst@cn.fujitsu.com
Cc: dyoung@redhat.com
Cc: m.mizuma@jp.fujitsu.com
Link: http://lkml.kernel.org/r/1494654390-23861-2-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar

Merge branch 'linus' into x86/boot, to pick up fixes

2017-01-28T08:30:11+00:00

Signed-off-by: Ingo Molnar

x86/boot: Fix KASLR and memmap= collision

2017-01-25T11:35:50+00:00

CONFIG_RANDOMIZE_BASE=y relocates the kernel to a random base address.

However it does not take into account the memmap= parameter passed in from
the kernel command line. This results in the kernel sometimes being put in
the middle of memmap.

Teach KASLR to not insert the kernel in memmap defined regions. We support
up to 4 memmap regions: any additional regions will cause KASLR to disable.

The mem_avoid set has been augmented to add up to 4 unusable regions of
memmaps provided by the user to exclude those regions from the set of valid
address range to insert the uncompressed kernel image.

The nn@ss ranges will be skipped by the mem_avoid set since it indicates
that memory is useable.

Signed-off-by: Dave Jiang 
Reviewed-by: Thomas Gleixner 
Acked-by: Kees Cook 
Acked-by: Baoquan He 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: dan.j.williams@intel.com
Cc: david@fromorbit.com
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/148417664156.131935.2248592164852799738.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Ingo Molnar

x86/boot: Add missing declaration of string functions

2017-01-09T10:53:05+00:00

Add the missing declarations of basic string functions to string.h to allow
a clean build.

Fixes: 5be865661516 ("String-handling functions for the new x86 setup code.")
Signed-off-by: Nicholas Mc Guire 
Link: http://lkml.kernel.org/r/1483781911-21399-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner

x86, asm: use bool for bitops and other assembly outputs

2016-06-08T19:41:20+00:00

The gcc people have confirmed that using "bool" when combined with
inline assembly always is treated as a byte-sized operand that can be
assumed to be 0 or 1, which is exactly what the SET instruction
emits.  Change the output types and intermediate variables of as many
operations as practical to "bool".

Signed-off-by: H. Peter Anvin 
Link: http://lkml.kernel.org/r/1465414726-197858-3-git-send-email-hpa@linux.intel.com
Reviewed-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Acked-by: Peter Zijlstra (Intel)