Commit Graph

979613 Commits

Author SHA1 Message Date
Aditya Srivastava
27b379af61 checkpatch: avoid COMMIT_LOG_LONG_LINE warning for signature tags
Currently checkpatch warns us for long lines in commits even for signature
tag lines.

Generally these lines exceed the 75-character limit because of:

 1) long names and long email address

 2) some comments on scoped review and acknowledgement, i.e., for a
    dedicated pointer on what was reported by the identity in
    'Reported-by'

 3) some additional comments on CC: stable@vger.org tags

Exclude signature tag lines from this class of warning.

There were 1896 COMMIT_LOG_LONG_LINE warnings in v5.6..v5.8 before this
patch application and 1879 afterwards.

A quick manual check found all the dropped warnings related to signature
tags.

Link: https://lkml.kernel.org/r/20201116083754.10629-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Dwaipayan Ray
e73d271594 checkpatch: fix spelling errors and remove repeated word
Delete repeated word in scripts/checkpatch.pl:
  "are are" -> "are"

Fix typos:
  "commments" -> "comments"
  "falsly" -> "falsely"

Link: https://lkml.kernel.org/r/20201113152316.62975-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Dwaipayan Ray
fccaebf00e checkpatch: improve email parsing
checkpatch doesn't report warnings for many common mistakes in emails.
Some of which are trailing commas and incorrect use of email comments.

At the same time several false positives are reported due to incorrect
handling of mail comments.  The most common of which is due to the
pattern:

<stable@vger.kernel.org> # X.X

Improve email parsing in checkpatch.

Some general email rules are defined:

- Multiple name comments should not be allowed.
- Comments inside address should not be allowed.
- In general comments should be enclosed within parentheses.
  Relaxation is given to comments beginning with #.
- Stable addresses should not begin with a name.
- Comments in stable addresses should begin only
  with a #.

Improvements to parsing:

- Detect and report unexpected content after email.
- Quoted names are excluded from comment parsing.
- Trailing dots, commas or quotes in email are removed during
  formatting. Correspondingly a BAD_SIGN_OFF warning
  is emitted.
- Improperly quoted email like '"name <address>"' are now
  warned about.

In addition, added fixes for all the possible rules.

Link: https://lore.kernel.org/linux-kernel-mentees/6c275d95c3033422addfc256a30e6ae3dd37941d.camel@perches.com/
Link: https://lore.kernel.org/linux-kernel-mentees/20201105200857.GC1333458@kroah.com/
Link: https://lkml.kernel.org/r/20201108100632.75340-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Joe Perches
0830aab0e1 checkpatch: add __alias and __weak to suggested __attribute__ conversions
Add __alias and __weak to the suggested __attribute__((<foo>))
conversions.

Link: https://lkml.kernel.org/r/7b74137743c58ce0633ec4d575b94e2210e4dbe7.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Aditya Srivastava
7580c5b9b4 checkpatch: add fix option for GERRIT_CHANGE_ID
Currently, whenever a Gerrit Change-Id is present in a commit,
checkpatch.pl warns to remove the Change-Id before submitting the patch.

E.g., running checkpatch on commit adc311a5bb ("iwlwifi: bump FW
API to 53 for 22000 series") reports this error:

  ERROR: Remove Gerrit Change-Id's before submitting upstream
  Change-Id: I5725e46394f3f53c3069723fd513cc53c7df383d

Provide a simple fix option by simply deleting the indicated line.

Link: https://lkml.kernel.org/r/20201030114447.24199-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Joe Perches
339f29d91a checkpatch: update __attribute__((section("name"))) quote removal
commit 33def8498f ("treewide: Convert macro and uses of
__section(foo) to __section("foo")") removed the stringification of the
section name and now requires quotes around the named section.

Update checkpatch to not remove any quotes when suggesting conversion
of __attribute__((section("name"))) to __section("name")

Miscellanea:

o Add section to the hash with __section replacement
o Remove separate test for __attribute__((section
o Remove the limitation on converting attributes containing only
  known, possible conversions.  Any unknown attribute types are now
  left as-is and known types are converted and moved before
  __attribute__ and removed from within the __attribute__((list...)).

[joe@perches.com: eliminate the separate test below the possible conversions loop]
  Link: https://lkml.kernel.org/r/58e9d55e933dc8fdc6af489f2ad797fa8eb13e44.camel@perches.com

Link: https://lkml.kernel.org/r/c04dd1c810e8d6a68e6a632e3191ae91651c8edf.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Tom Rix
47ca69b858 checkpatch: add a fixer for missing newline at eof
Remove the trailing error message from the fixed lines.

Link: https://lkml.kernel.org/r/20201017142546.28988-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Dwaipayan Ray
7ebe1d173c checkpatch: extend attributes check to handle more patterns
It is generally preferred that the macros from
include/linux/compiler_attributes.h are used, unless there is a reason not
to.

checkpatch currently checks __attribute__ for each of packed, aligned,
section, printf, scanf, and weak.  Other declarations in
compiler_attributes.h are not handled.

Add a generic test to check the presence of such attributes.  Some
attributes require more specific handling and are kept separate.

Also add fixes to the generic attributes check to substitute the correct
conversions.

New attributes which are now handled are:

__always_inline__
__assume_aligned__(a, ## __VA_ARGS__)
__cold__
__const__
__copy__(symbol)
__designated_init__
__externally_visible__
__gnu_inline__
__malloc__
__mode__(x)
__no_caller_saved_registers__
__noclone__
__noinline__
__nonstring__
__noreturn__
__pure__
__unused__
__used__

Declarations which contain multiple attributes like
__attribute__((__packed__, __cold__)) are also handled except when proper
conversions for one or more attributes of the list cannot be determined.

Link: https://lore.kernel.org/linux-kernel-mentees/3ec15b41754b01666d94b76ce51b9832c2dd577a.camel@perches.com/
Link: https://lkml.kernel.org/r/20201025193103.23223-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Joe Perches
dc58bc553e checkpatch: allow --fix removal of unnecessary break statements
switch/case use of break after a return, goto or break is unnecessary.

There is an existing warning for the return and goto uses, so add
break and a --fix option too.

Link: https://lkml.kernel.org/r/d9ea654104d55f590fb97d252d64a66b23c1a096.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Joe Perches
73169765e6 checkpatch: prefer static const declarations
There are about 100,000 uses of 'static const <type>' but about 400 uses
of 'static <type> const' in the kernel where type is not a pointer.

The kernel almost always uses "static const" over "const static" as there
is a compiler warning for that declaration style.

But there is no compiler warning for "static <type> const".

So add a checkpatch warning for the atypical declaration uses of.

	const static <type> <foo>
and
	static <type> const <foo>

For example:

  $ ./scripts/checkpatch.pl -f --emacs --quiet --nosummary -types=static_const arch/arm/crypto/aes-ce-glue.c
  arch/arm/crypto/aes-ce-glue.c:75: WARNING: Move const after static - use 'static const u8'
  #75: FILE: arch/arm/crypto/aes-ce-glue.c:75:
  +	static u8 const rcon[] = {

Link: https://lkml.kernel.org/r/4b863be68e679546b40d50b97a4a806c03056a1c.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Łukasz Stelmach
4104a20646 checkpatch: ignore generated CamelCase defines and enum values
Ignore autogenerated CamelCase-like defines and enum values like
DRM_MODE_CONNECTOR_Unknown or ETHTOOL_LINK_MODE_Asym_Pause_BIT.

Link: https://lkml.kernel.org/r/20201022184916.7904-1-l.stelmach@samsung.com
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:17 -08:00
Aditya Srivastava
8d0325cc74 checkpatch: fix false positives in REPEATED_WORD warning
Presence of hexadecimal address or symbol results in false warning
message by checkpatch.pl.

For example, running checkpatch on commit b8ad540dd4 ("mptcp: fix
memory leak in mptcp_subflow_create_socket()") results in warning:

  WARNING:REPEATED_WORD: Possible repeated word: 'ff'
      00 00 00 00 00 00 00 00 00 2f 30 0a 81 88 ff ff  ........./0.....

Similarly, the presence of list command output in commit results in
an unnecessary warning.

For example, running checkpatch on commit 899e5ffbf2 ("perf record:
Introduce --switch-output-event") gives:

  WARNING:REPEATED_WORD: Possible repeated word: 'root'
    dr-xr-x---. 12 root root    4096 Apr 27 17:46 ..

Here, it reports 'ff' and 'root' to be repeated, but it is in fact part
of some address or code, where it has to be repeated.

In these cases, the intent of the warning to find stylistic issues in
commit messages is not met and the warning is just completely wrong in
this case.

To avoid these warnings, add an additional regex check for the directory
permission pattern and avoid checking the line for this class of
warning.  Similarly, to avoid hex pattern, check if the word consists of
hex symbols and skip this warning if it is not among the common english
words formed using hex letters.

A quick evaluation on v5.6..v5.8 showed that this fix reduces
REPEATED_WORD warnings by the frequency of 1890.

A quick manual check found all cases are related to hex output or list
command outputs in commit messages.

Link: https://lkml.kernel.org/r/20201024102253.13614-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Dwaipayan Ray
1db81a682a checkpatch: add new exception to repeated word check
Recently, commit 4f6ad8aa1eac ("checkpatch: move repeated word test")
moved the repeated word test to check for more file types. But after
this, if checkpatch.pl is run on MAINTAINERS, it generates several
new warnings of the type:

  WARNING: Possible repeated word: 'git'

For example:

  WARNING: Possible repeated word: 'git'
  +T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml.git

So, the pattern "git git://..." is a false positive in this case.

There are several other combinations which may produce a wrong warning
message, such as "@size size", ":Begin begin", etc.

Extend repeated word check to compare the characters before and after
the word matches.

If there is a non whitespace character before the first word or a non
whitespace character excluding punctuation characters after the second
word, then the check is skipped and the warning is avoided.

Also add case insensitive word matching to the repeated word check.

Link: https://lore.kernel.org/linux-kernel-mentees/81b6a0bb2c7b9256361573f7a13201ebcd4876f1.camel@perches.com/
Link: https://lkml.kernel.org/r/20201017162732.152351-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Aditya Srivastava <yashsri421@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Gao Xiang
89b158635a lib/lz4: explicitly support in-place decompression
LZ4 final literal copy could be overlapped when doing
in-place decompression, so it's unsafe to just use memcpy()
on an optimized memcpy approach but memmove() instead.

Upstream LZ4 has updated this years ago [1] (and the impact
is non-sensible [2] plus only a few bytes remain), this commit
just synchronizes LZ4 upstream code to the kernel side as well.

It can be observed as EROFS in-place decompression failure
on specific files when X86_FEATURE_ERMS is unsupported,
memcpy() optimization of commit 59daa706fb ("x86, mem:
Optimize memcpy by avoiding memory false dependece") will
be enabled then.

Currently most modern x86-CPUs support ERMS, these CPUs just
use "rep movsb" approach so no problem at all. However, it can
still be verified with forcely disabling ERMS feature...

arch/x86/lib/memcpy_64.S:
        ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
-                     "jmp memcpy_erms", X86_FEATURE_ERMS
+                     "jmp memcpy_orig", X86_FEATURE_ERMS

We didn't observe any strange on arm64/arm/x86 platform before
since most memcpy() would behave in an increasing address order
("copy upwards" [3]) and it's the correct order of in-place
decompression but it really needs an update to memmove() for sure
considering it's an undefined behavior according to the standard
and some unique optimization already exists in the kernel.

[1] 33cb8518ac
[2] https://github.com/lz4/lz4/pull/717#issuecomment-497818921
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=12518

Link: https://lkml.kernel.org/r/20201122030749.2698994-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Nick Terrell <terrelln@fb.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Alexey Dobriyan
506dfc9906 lib: cleanup kstrto*() usage
Use proper conversion functions.  kstrto*() variants exist for all
standard types.

Link: https://lkml.kernel.org/r/20201122123410.GB92364@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Francis Laniel
d58b0b1a41 drivers/misc/lkdtm/lkdtm.h: correct wrong filenames in comment
In lkdtm.h, files targeted in comments are named "lkdtm_file.c" while
there are named "file.c" in directory.

Link: https://lkml.kernel.org/r/20201122162451.27551-6-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Francis Laniel
febebaf366 drivers/misc/lkdtm: add new file in LKDTM to test fortified strscpy
This new test ensures that fortified strscpy has the same behavior than
vanilla strscpy (e.g.  returning -E2BIG when src content is truncated).
Finally, it generates a crash at runtime because there is a write overflow
in destination string.

Link: https://lkml.kernel.org/r/20201122162451.27551-5-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Francis Laniel
33e56a59e6 string.h: add FORTIFY coverage for strscpy()
The fortified version of strscpy ensures the following before vanilla strscpy
is called:

1. There is no read overflow because we either size is smaller than
   src length or we shrink size to src length by calling fortified
   strnlen.

2. There is no write overflow because we either failed during
   compilation or at runtime by checking that size is smaller than dest
   size.

Link: https://lkml.kernel.org/r/20201122162451.27551-4-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Daniel Axtens
d96938daae lkdtm: tests for FORTIFY_SOURCE
Add code to test both:

 - runtime detection of the overrun of a structure. This covers the
   __builtin_object_size(x, 0) case. This test is called FORTIFY_OBJECT.

 - runtime detection of the overrun of a char array within a structure.
   This covers the __builtin_object_size(x, 1) case which can be used
   for some string functions. This test is called FORTIFY_SUBOBJECT.

Link: https://lkml.kernel.org/r/20201122162451.27551-3-laniel_francis@privacyrequired.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Daniel Axtens
6a39e62abb lib: string.h: detect intra-object overflow in fortified string functions
Patch series "Fortify strscpy()", v7.

This patch implements a fortified version of strscpy() enabled by setting
CONFIG_FORTIFY_SOURCE=y.  The new version ensures the following before
calling vanilla strscpy():

1. There is no read overflow because either size is smaller than src
   length or we shrink size to src length by calling fortified strnlen().

2. There is no write overflow because we either failed during
   compilation or at runtime by checking that size is smaller than dest
   size.  Note that, if src and dst size cannot be got, the patch defaults
   to call vanilla strscpy().

The patches adds the following:

1. Implement the fortified version of strscpy().

2. Add a new LKDTM test to ensures the fortified version still returns
   the same value as the vanilla one while panic'ing when there is a write
   overflow.

3. Correct some typos in LKDTM related file.

I based my modifications on top of two patches from Daniel Axtens which
modify calls to __builtin_object_size, in fortified string functions, to
ensure the true size of char * are returned and not the surrounding
structure size.

About performance, I measured the slow down of fortified strscpy(), using
the vanilla one as baseline.  The hardware I used is an Intel i3 2130 CPU
clocked at 3.4 GHz.  I ran "Linux 5.10.0-rc4+ SMP PREEMPT" inside qemu
3.10 with 4 CPU cores.  The following code, called through LKDTM, was used
as a benchmark:

#define TIMES 10000
	char *src;
	char dst[7];
	int i;
	ktime_t begin;

	src = kstrdup("foobar", GFP_KERNEL);

	if (src == NULL)
		return;

	begin = ktime_get();
	for (i = 0; i < TIMES; i++)
		strscpy(dst, src, strlen(src));
	pr_info("%d fortified strscpy() tooks %lld", TIMES, ktime_get() - begin);

	begin = ktime_get();
	for (i = 0; i < TIMES; i++)
		__real_strscpy(dst, src, strlen(src));
	pr_info("%d vanilla strscpy() tooks %lld", TIMES, ktime_get() - begin);

	kfree(src);

I called the above code 30 times to compute stats for each version (in ns,
round to int):

| version   | mean    | std    | median  | 95th    |
| --------- | ------- | ------ | ------- | ------- |
| fortified | 245_069 | 54_657 | 216_230 | 331_122 |
| vanilla   | 172_501 | 70_281 | 143_539 | 219_553 |

On average, fortified strscpy() is approximately 1.42 times slower than
vanilla strscpy().  For the 95th percentile, the fortified version is
about 1.50 times slower.

So, clearly the stats are not in favor of fortified strscpy().  But, the
fortified version loops the string twice (one in strnlen() and another in
vanilla strscpy()) while the vanilla one only loops once.  This can
explain why fortified strscpy() is slower than the vanilla one.

This patch (of 5):

When the fortify feature was first introduced in commit 6974f0c455
("include/linux/string.h: add the option of fortified string.h
functions"), Daniel Micay observed:

  * It should be possible to optionally use __builtin_object_size(x, 1) for
    some functions (C strings) to detect intra-object overflows (like
    glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative
    approach to avoid likely compatibility issues.

This is a case that often cannot be caught by KASAN. Consider:

struct foo {
    char a[10];
    char b[10];
}

void test() {
    char *msg;
    struct foo foo;

    msg = kmalloc(16, GFP_KERNEL);
    strcpy(msg, "Hello world!!");
    // this copy overwrites foo.b
    strcpy(foo.a, msg);
}

The questionable copy overflows foo.a and writes to foo.b as well.  It
cannot be detected by KASAN.  Currently it is also not detected by
fortify, because strcpy considers __builtin_object_size(x, 0), which
considers the size of the surrounding object (here, struct foo).  However,
if we switch the string functions over to use __builtin_object_size(x, 1),
the compiler will measure the size of the closest surrounding subobject
(here, foo.a), rather than the size of the surrounding object as a whole.
See https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html for more
info.

Only do this for string functions: we cannot use it on things like memcpy,
memmove, memcmp and memchr_inv due to code like this which purposefully
operates on multiple structure members: (arch/x86/kernel/traps.c)

	/*
	 * regs->sp points to the failing IRET frame on the
	 * ESPFIX64 stack.  Copy it to the entry stack.  This fills
	 * in gpregs->ss through gpregs->ip.
	 *
	 */
	memmove(&gpregs->ip, (void *)regs->sp, 5*8);

This change passes an allyesconfig on powerpc and x86, and an x86 kernel
built with it survives running with syz-stress from syzkaller, so it seems
safe so far.

Link: https://lkml.kernel.org/r/20201122162451.27551-1-laniel_francis@privacyrequired.com
Link: https://lkml.kernel.org/r/20201122162451.27551-2-laniel_francis@privacyrequired.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Nick Desaulniers
ff72daa371 lib/string: remove unnecessary #undefs
A few architecture specific string.h functions used to be implemented in
terms of preprocessor defines to the corresponding compiler builtins.
Since this is no longer the case, remove unused #undefs.

Only memcmp is still defined in terms of builtins for a few arches.

Link: https://github.com/ClangBuiltLinux/linux/issues/428
Link: https://lkml.kernel.org/r/20201120041113.89382-1-ndesaulniers@google.com
Fixes: 5f074f3e19 ("lib/string.c: implement a basic bcmp")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Jakub Jelinek
2f78788b55 ilog2: improve ilog2 for constant arguments
As discussed in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97445 the
const_ilog2 macro generates a lot of code which interferes badly with GCC
inlining heuristics, until it can be proven that the ilog2 argument can or
can't be simplified into a constant.

It can be expressed using __builtin_clzll builtin which is supported by
GCC 3.4 and later and when used only in the __builtin_constant_p guarded
code it ought to always fold back to a constant.  Other compilers support
the same builtin for many years too.

Other option would be to change the const_ilog2 macro, though as the
description says it is meant to be used also in C constant expressions,
and while GCC will fold it to constant with constant argument even in
those, perhaps it is better to avoid using extensions in that case.

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/20201120125154.GB3040@hirez.programming.kicks-ass.net
Link: https://lkml.kernel.org/r/20201021132718.GB2176@tucnak
Signed-off-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Andy Shevchenko
7546861a8c lib/cmdline_kunit: add a new test suite for cmdline API
Test get_option() for a starter which is provided by cmdline.c.

[akpm@linux-foundation.org: fix warning by constifying cmdline_test_values]
[andriy.shevchenko@linux.intel.com: type of expected returned values should be int]
  Link: https://lkml.kernel.org/r/20201116104244.15472-1-andriy.shevchenko@linux.intel.com
[andriy.shevchenko@linux.intel.com: provide meaningful MODULE_LICENSE()]
  Link: https://lkml.kernel.org/r/20201116104257.15527-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20201112180732.75589-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Andy Shevchenko
6b2b6b8646 lib/cmdline: allow NULL to be an output for get_option()
In the future we would like to use get_option() to only validate the
string and parse it separately.  To achieve this, allow NULL to be an
output for get_option().

Link: https://lkml.kernel.org/r/20201112180732.75589-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Andy Shevchenko
e291851d65 lib/cmdline: fix get_option() for strings starting with hyphen
When string doesn't have an integer and starts from hyphen get_option()
may return interesting results.  Fix it to return 0.

The simple_strtoull() is used due to absence of simple_strtoul() in a boot
code on some architectures.

Note, the Fixes tag below is rather for anthropological curiosity.

Link: https://lkml.kernel.org/r/20201112180732.75589-4-andriy.shevchenko@linux.intel.com
Fixes: f68565831e72 ("Import 2.4.0-test2pre3")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Sebastian Andrzej Siewior
45e3d5a2af lib/test_lockup.c: minimum fix to get it compiled on PREEMPT_RT
On PREEMPT_RT the locks are quite different so they can't be tested as it
is done below.  The alternative is to test for the waitlock within
rtmutex.

This is the bare minimun to get it compiled.  Problems which exist on
PREEMP_RT:

 - none of the locks (spinlock_t, rwlock_t, mutex_t, rw_semaphore) may
   be acquired with disabled preemption or interrupts.

   If I read the code correct the it is possible to acquire a mutex_t
   with disabled interrupts.

   I don't know how to obtain a lock pointer. Technically they are not
   exported to userland.

 - memory can not be allocated with disabled preemption or interrupts
   even with GFP_ATOMIC.

Link: https://lkml.kernel.org/r/20201028181041.xyeothhkouc3p4md@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Gustavo A. R. Silva
180644f80a lib/stackdepot.c: use array_size() helper in jhash2()
Use array_size() helper instead of the open-coded version in jhash2().
These sorts of multiplication factors need to be wrapped in array_size().

Also, use the preferred form for passing the size of an object type.

Link: https://lkml.kernel.org/r/cb8a682e4bba4dbddd2bd8aca7f8c02fea89639b.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Gustavo A. R. Silva
47e684aaa2 lib/stackdepot.c: use flex_array_size() helper in memcpy()
Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer overflows,
while at the same time makes it explicitly clear that we are dealing with
a flexible array member.

Link: https://lkml.kernel.org/r/186e37fe07196ee41a0e562fa8a8cb7a01112ec5.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Gustavo A. R. Silva
3a2b67e6e3 lib/stackdepot.c: replace one-element array with flexible-array member
Patch series "lib/stackdepot.c: Replace one-element array with flexible-array member".

This series aims to replace a one-element array with a flexible-array
member.  Also, make use of the struct_size(), flexible_array_size() and
array_size() helpers.

This patch (of 3):

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure.  Kernel code
should always use “flexible array members”[1] for these cases.  The
older style of one-element or zero-length arrays should no longer be
used[2].

Refactor the code according to the use of a flexible-array member in
struct stack_record, instead of a one-element array, and use the
struct_size() helper to calculate the size for the allocation.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://lkml.kernel.org/r/cover.1601565471.git.gustavoars@kernel.org
Link: https://lore.kernel.org/lkml/5f75876b.x9zdN10esiC0qLHV%25lkp@intel.com/
Link: https://lkml.kernel.org/r/2f1e6a17aaa891ad9c58817cf0a10b8ab8894f59.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Geert Uytterhoeven
0ae446e4b9 lib/test_free_pages.c: add basic progress indicators
The test module to check that free_pages() does not leak memory does not
provide any feedback whatsoever its state or progress, but may take some
time on slow machines.  Add the printing of messages upon starting each
phase of the test, and upon completion.

Link: https://lkml.kernel.org/r/20201018140445.20972-1-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Ma, Jianpeng
ab7d7798da bitmap: remove unused function declaration
Link: https://lkml.kernel.org/r/BN7PR11MB26097166B6B46387D8A1ABA4FDE30@BN7PR11MB2609.namprd11.prod.outlook.com
Fixes: 2afe27c718 ("lib/bitmap.c: bitmap_[empty,full]: remove code duplication")
Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:16 -08:00
Andy Shevchenko
0bb8677955 include/linux/bitmap.h: convert bitmap_empty() / bitmap_full() to return boolean
There is no need to return int type out of boolean expression.

Link: https://lkml.kernel.org/r/20201027180936.20806-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Hui Su
35189b8ff1 kernel/acct.c: use #elif instead of #end and #elif
Cleanup: use #elif instead of #end and #elif.

Link: https://lkml.kernel.org/r/20201015150736.GA91603@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Andy Shevchenko
aa6159ab99 kernel.h: split out mathematical helpers
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out
mathematical helpers.

At the same time convert users in header and lib folder to use new
header.  Though for time being include new header back to kernel.h to
avoid twisted indirected includes for existing users.

[sfr@canb.auug.org.au: fix powerpc build]
  Link: https://lkml.kernel.org/r/20201029150809.13059608@canb.auug.org.au

Link: https://lkml.kernel.org/r/20201028173212.41768-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Christophe Leroy
0a571b085f asm-generic: force inlining of get_order() to work around gcc10 poor decision
When building mpc885_ads_defconfig with gcc 10.1,
the function get_order() appears 50 times in vmlinux:

  [linux]# ppc-linux-objdump -x vmlinux | grep get_order | wc -l
  50

  [linux]# size vmlinux
     text	   data	    bss	    dec	    hex	filename
  3842620	 675624	 135160	4653404	 47015c	vmlinux

In the old days, marking a function 'static inline' was forcing GCC to
inline, but since commit ac7c3e4ff4 ("compiler: enable
CONFIG_OPTIMIZE_INLINING forcibly") GCC may decide to not inline a
function.

It looks like GCC 10 is taking poor decisions on this.

get_order() compiles into the following tiny function, occupying 20
bytes of text.

  0000007c <get_order>:
    7c:   38 63 ff ff     addi    r3,r3,-1
    80:   54 63 a3 3e     rlwinm  r3,r3,20,12,31
    84:   7c 63 00 34     cntlzw  r3,r3
    88:   20 63 00 20     subfic  r3,r3,32
    8c:   4e 80 00 20     blr

By forcing get_order() to be __always_inline, the size of text is
reduced by 1940 bytes, that is almost twice the space occupied by
50 times get_order()

  [linux-powerpc]# size vmlinux
     text	   data	    bss	    dec	    hex	filename
  3840680	 675588	 135176	4651444	 46f9b4	vmlinux

Link: https://lkml.kernel.org/r/96c6172d619c51acc5c1c4884b80785c59af4102.1602949927.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Hui Su
a9389683fa fs/proc: make pde_get() return nothing
We don't need pde_get()'s return value, so make pde_get() return nothing

Link: https://lkml.kernel.org/r/20201211061944.GA2387571@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Alexey Dobriyan
c6c75deda8 proc: fix lookup in /proc/net subdirectories after setns(2)
Commit 1fde6f21d9 ("proc: fix /proc/net/* after setns(2)") only forced
revalidation of regular files under /proc/net/

However, /proc/net/ is unusual in the sense of /proc/net/foo handlers
take netns pointer from parent directory which is old netns.

Steps to reproduce:

	(void)open("/proc/net/sctp/snmp", O_RDONLY);
	unshare(CLONE_NEWNET);

	int fd = open("/proc/net/sctp/snmp", O_RDONLY);
	read(fd, &c, 1);

Read will read wrong data from original netns.

Patch forces lookup on every directory under /proc/net .

Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain
Fixes: 1da4d377f9 ("proc: revalidate misc dentries")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Anand K Mistry
fe71988834 proc: provide details on indirect branch speculation
Similar to speculation store bypass, show information about the indirect
branch speculation mode of a task in /proc/$pid/status.

For testing/benchmarking, I needed to see whether IB (Indirect Branch)
speculation (see Spectre-v2) is enabled on a task, to see whether an
IBPB instruction should be executed on an address space switch.
Unfortunately, this information isn't available anywhere else and
currently the only way to get it is to hack the kernel to expose it
(like this change).  It also helped expose a bug with conditional IB
speculation on certain CPUs.

Another place this could be useful is to audit the system when using
sanboxing.  With this change, I can confirm that seccomp-enabled
process have IB speculation force disabled as expected when the kernel
command line parameter `spectre_v2_user=seccomp`.

Since there's already a 'Speculation_Store_Bypass' field, I used that
as precedent for adding this one.

[amistry@google.com: remove underscores from field name to workaround documentation issue]
  Link: https://lkml.kernel.org/r/20201106131015.v2.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid

Link: https://lkml.kernel.org/r/20201030172731.1.I7782b0cedb705384a634cfd8898eb7523562da99@changeid
Signed-off-by: Anand K Mistry <amistry@google.com>
Cc: Anthony Steinhauser <asteinhauser@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Anand K Mistry <amistry@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Randy Dunlap
d2928e8550 procfs: delete duplicated words + other fixes
Delete repeated words in fs/proc/.
{the, which}
where "which which" was changed to "with which".

Link: https://lkml.kernel.org/r/20201028191525.13413-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Thomas Gleixner
4083a281e3 alpha: replace bogus in_interrupt()
in_interrupt() is true for a variety of things including bottom half
disabled regions.  Deducing hard interrupt context from it is dubious at
best.

Use in_irq() which is true if called in hard interrupt context.  Otherwise
calling irq_exit() would do more harm than good.

Link: https://lkml.kernel.org/r/20201113135832.2202833-1-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Serge Belyshev <belyshev@depni.sinp.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Laurent Dufour
7c33023aad mm/memory_hotplug: quieting offline operation
On PowerPC, when dymically removing memory from a system we can see in the
console a lot of messages like this:

[  186.575389] Offlined Pages 4096

This message is displayed on each LMB (256MB) removed, which means that we
removing 1TB of memory, this message is displayed 4096 times.

Moving it to DEBUG to not flood the console.

Link: https://lkml.kernel.org/r/20201211150157.91399-1-ldufour@linux.ibm.com
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Zhaoyang Huang
b50da6e9f4 mm: fix a race on nr_swap_pages
The scenario on which "Free swap = -4kB" happens in my system, which is caused
by several get_swap_pages racing with each other and show_swap_cache_info
happens simutaniously. No need to add a lock on get_swap_page_of_type as we
remove "Presub/PosAdd" here.

ProcessA			ProcessB			ProcessC
ngoals = 1			ngoals = 1
avail = nr_swap_pages(1)	avail = nr_swap_pages(1)
nr_swap_pages(1) -= ngoals
				nr_swap_pages(0) -= ngoals
								nr_swap_pages = -1

Link: https://lkml.kernel.org/r/1607050340-4535-1-git-send-email-zhaoyang.huang@unisoc.com
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15 22:46:15 -08:00
Linus Torvalds
d01e7f10da Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull exec-update-lock update from Eric Biederman:
 "The key point of this is to transform exec_update_mutex into a
  rw_semaphore so readers can be separated from writers.

  This makes it easier to understand what the holders of the lock are
  doing, and makes it harder to contend or deadlock on the lock.

  The real deadlock fix wound up in perf_event_open"

* 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  exec: Transform exec_update_mutex into a rw_semaphore
2020-12-15 19:36:48 -08:00
Linus Torvalds
faf145d6f3 Merge branch 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull execve updates from Eric Biederman:
 "This set of changes ultimately fixes the interaction of posix file
  lock and exec. Fundamentally most of the change is just moving where
  unshare_files is called during exec, and tweaking the users of
  files_struct so that the count of files_struct is not unnecessarily
  played with.

  Along the way fcheck and related helpers were renamed to more
  accurately reflect what they do.

  There were also many other small changes that fell out, as this is the
  first time in a long time much of this code has been touched.

  Benchmarks haven't turned up any practical issues but Al Viro has
  observed a possibility for a lot of pounding on task_lock. So I have
  some changes in progress to convert put_files_struct to always rcu
  free files_struct. That wasn't ready for the merge window so that will
  have to wait until next time"

* 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  exec: Move io_uring_task_cancel after the point of no return
  coredump: Document coredump code exclusively used by cell spufs
  file: Remove get_files_struct
  file: Rename __close_fd_get_file close_fd_get_file
  file: Replace ksys_close with close_fd
  file: Rename __close_fd to close_fd and remove the files parameter
  file: Merge __alloc_fd into alloc_fd
  file: In f_dupfd read RLIMIT_NOFILE once.
  file: Merge __fd_install into fd_install
  proc/fd: In fdinfo seq_show don't use get_files_struct
  bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
  proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu
  file: Implement task_lookup_next_fd_rcu
  kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
  proc/fd: In tid_fd_mode use task_lookup_fd_rcu
  file: Implement task_lookup_fd_rcu
  file: Rename fcheck lookup_fd_rcu
  file: Replace fcheck_files with files_lookup_fd_rcu
  file: Factor files_lookup_fd_locked out of fcheck_files
  file: Rename __fcheck_files to files_lookup_fd_raw
  ...
2020-12-15 19:29:43 -08:00
Linus Torvalds
6febd8bef3 Merge branch 'signal-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull signal cleanup from Eric Biederman:
 "Remove a never used HP-UX compatibility from parisc headers and
  consolidating the SA_* flags definitions into a generic header as much
  as possible.

  We only have 32 SA_* flag bits total, so we need to be careful. But as
  this is the first addition in a decade or so I think we are fine for
  the forseeable future"

* 'signal-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal/parisc: Remove parisc specific definition of __ARCH_UAPI_SA_FLAGS
2020-12-15 19:14:27 -08:00
Linus Torvalds
345d4ab5e0 close-range-openat2-v5.11
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Merge tag 'close-range-openat2-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull close_range/openat2 updates from Christian Brauner:
 "This contains a fix for openat2() to make RESOLVE_BENEATH and
  RESOLVE_IN_ROOT mutually exclusive. It doesn't make sense to specify
  both at the same time. The openat2() selftests have been extended to
  verify that these two flags can't be specified together.

  This also adds the CLOSE_RANGE_CLOEXEC flag to close_range() which
  allows to mark a range of file descriptors as close-on-exec without
  actually closing them.

  This is useful in general but the use-case that triggered the patch is
  installing a seccomp profile in the calling task before exec. If the
  seccomp profile wants to block the close_range() syscall it obviously
  can't use it to close all fds before exec. If it calls close_range()
  before installing the seccomp profile it needs to take care not to
  close fds that it will still need before the exec meaning it would
  have to call close_range() multiple times on different ranges and then
  still fall back to closing fds one by one right before the exec.

  CLOSE_RANGE_CLOEXEC allows to solve this problem relying on the exec
  codepath to get rid of the unwanted fds. The close_range() tests have
  been expanded to verify that CLOSE_RANGE_CLOEXEC works"

* tag 'close-range-openat2-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  selftests: core: add tests for CLOSE_RANGE_CLOEXEC
  fs, close_range: add flag CLOSE_RANGE_CLOEXEC
  selftests: openat2: add RESOLVE_ conflict test
  openat2: reject RESOLVE_BENEATH|RESOLVE_IN_ROOT
2020-12-15 19:11:47 -08:00
Linus Torvalds
37373d9c37 Merge branch 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull regset updates from Al Viro:
 "Dead code removal, mostly.

  The only exception is a bit of cleanups on itanic (getting rid of
  redundant stack unwinds - each access_uarea() call does it and we call
  that 7 times in a row in ptrace_[sg]etregs(), *after* having done it
  ourselves in the caller; location where the user registers have been
  spilled won't change under us, and we can bloody well just call
  access_elf_reg() directly, giving it the unw_frame_info we'd
  calculated for our own purposes)"

* 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  c6x: kill ELF_CORE_COPY_FPREGS
  whack-a-mole: USE_ELF_CORE_DUMP
  [ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea()
  [ia64] missed cleanups from switch to regset coredumps
  arm: kill dump_task_regs()
2020-12-15 19:09:44 -08:00
Linus Torvalds
1a825a6a0e Merge branch 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull epoll updates from Al Viro:
 "Deal with epoll loop check/removal races sanely (among other things).

  The solution merged last cycle (pinning a bunch of struct file
  instances) had been forced by the wrong data structures; untangling
  that takes a bunch of preparations, but it's worth doing - control
  flow in there is ridiculously overcomplicated. Memory footprint has
  also gone down, while we are at it.

  This is not all I want to do in the area, but since I didn't get
  around to posting the followups they'll have to wait for the next
  cycle"

* 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  epoll: take epitem list out of struct file
  epoll: massage the check list insertion
  lift rcu_read_lock() into reverse_path_check()
  convert ->f_ep_links/->fllink to hlist
  ep_insert(): move creation of wakeup source past the fl_ep_links insertion
  fold ep_read_events_proc() into the only caller
  take the common part of ep_eventpoll_poll() and ep_item_poll() into helper
  ep_insert(): we only need tep->mtx around the insertion itself
  ep_insert(): don't open-code ep_remove() on failure exits
  lift locking/unlocking ep->mtx out of ep_{start,done}_scan()
  ep_send_events_proc(): fold into the caller
  lift the calls of ep_send_events_proc() into the callers
  lift the calls of ep_read_events_proc() into the callers
  ep_scan_ready_list(): prepare to splitup
  ep_loop_check_proc(): saner calling conventions
  get rid of ep_push_nested()
  ep_loop_check_proc(): lift pushing the cookie into callers
  clean reverse_path_check_proc() a bit
  reverse_path_check_proc(): don't bother with cookies
  reverse_path_check_proc(): sane arguments
  ...
2020-12-15 19:01:08 -08:00
Linus Torvalds
e88bd82698 Changes since last update:
- get rid of magical page->mapping type marks;
 
  - switch to inplace I/O under low memory scenario;
 
  - return the correct block number for bmap();
 
  - some minor cleanups.
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Merge tag 'erofs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs updates from Gao Xiang:
 "This cycle we got rid of magical page->mapping type marks for
  temporary pages which had some concern before, now such usage is
  replaced with specific page->private.

  Also switch to inplace I/O instead of allocating extra cached pages to
  avoid direct reclaim under low memory scenario.

  There are some bmap bugfix and minor cleanups as well"

* tag 'erofs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: avoid using generic_block_bmap
  erofs: force inplace I/O under low memory scenario
  erofs: simplify try_to_claim_pcluster()
  erofs: insert to managed cache after adding to pcl
  erofs: get rid of magical Z_EROFS_MAPPING_STAGING
  erofs: remove a void EROFS_VERSION macro set in Makefile
2020-12-15 18:58:27 -08:00
Linus Torvalds
1a50ede2b3 Highlights:
- Improve support for re-exporting NFS mounts
 - Replace NFSv4 XDR decoding C macros with xdr_stream helpers
 - Support for multiple RPC/RDMA chunks per RPC transaction
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Merge tag 'nfsd-5.11' of git://git.linux-nfs.org/projects/cel/cel-2.6

Pull nfsd updates from Chuck Lever:
 "Several substantial changes this time around:

   - Previously, exporting an NFS mount via NFSD was considered to be an
     unsupported feature. With v5.11, the community has attempted to
     make re-exporting a first-class feature of NFSD.

     This would enable the Linux in-kernel NFS server to be used as an
     intermediate cache for a remotely-located primary NFS server, for
     example, even with other NFS server implementations, like a NetApp
     filer, as the primary.

   - A short series of patches brings support for multiple RPC/RDMA data
     chunks per RPC transaction to the Linux NFS server's RPC/RDMA
     transport implementation.

     This is a part of the RPC/RDMA spec that the other premiere
     NFS/RDMA implementation (Solaris) has had for a very long time, and
     completes the implementation of RPC/RDMA version 1 in the Linux
     kernel's NFS server.

   - Long ago, NFSv4 support was introduced to NFSD using a series of C
     macros that hid dprintk's and goto's. Over time, the kernel's XDR
     implementation has been greatly improved, but these C macros have
     remained and become fallow. A series of patches in this pull
     request completely replaces those macros with the use of current
     kernel XDR infrastructure. Benefits include:

       - More robust input sanitization in NFSD's NFSv4 XDR decoders.

       - Make it easier to use common kernel library functions that use
         XDR stream APIs (for example, GSS-API).

       - Align the structure of the source code with the RFCs so it is
         easier to learn, verify, and maintain our XDR implementation.

       - Removal of more than a hundred hidden dprintk() call sites.

       - Removal of some explicit manipulation of pages to help make the
         eventual transition to xdr->bvec smoother.

   - On top of several related fixes in 5.10-rc, there are a few more
     fixes to get the Linux NFSD implementation of NFSv4.2 inter-server
     copy up to speed.

  And as usual, there is a pinch of seasoning in the form of a
  collection of unrelated minor bug fixes and clean-ups.

  Many thanks to all who contributed this time around!"

* tag 'nfsd-5.11' of git://git.linux-nfs.org/projects/cel/cel-2.6: (131 commits)
  nfsd: Record NFSv4 pre/post-op attributes as non-atomic
  nfsd: Set PF_LOCAL_THROTTLE on local filesystems only
  nfsd: Fix up nfsd to ensure that timeout errors don't result in ESTALE
  exportfs: Add a function to return the raw output from fh_to_dentry()
  nfsd: close cached files prior to a REMOVE or RENAME that would replace target
  nfsd: allow filesystems to opt out of subtree checking
  nfsd: add a new EXPORT_OP_NOWCC flag to struct export_operations
  Revert "nfsd4: support change_attr_type attribute"
  nfsd4: don't query change attribute in v2/v3 case
  nfsd: minor nfsd4_change_attribute cleanup
  nfsd: simplify nfsd4_change_info
  nfsd: only call inode_query_iversion in the I_VERSION case
  nfs_common: need lock during iterate through the list
  NFSD: Fix 5 seconds delay when doing inter server copy
  NFSD: Fix sparse warning in nfs4proc.c
  SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall
  sunrpc: clean-up cache downcall
  nfsd: Fix message level for normal termination
  NFSD: Remove macros that are no longer used
  NFSD: Replace READ* macros in nfsd4_decode_compound()
  ...
2020-12-15 18:52:30 -08:00