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2020-12-15checkpatch: add fix option for ASSIGNMENT_CONTINUATIONSAditya Srivastava1-2/+8
Currently, checkpatch warns us if an assignment operator is placed at the start of a line and not at the end of previous line. E.g., running checkpatch on commit 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug") reports: CHECK: Assignment operator '=' should be on the previous line + struct netvsc_device *nvdev + = container_of(w, struct netvsc_device, subchan_work); Provide a simple fix by appending assignment operator to the previous line and removing from the current line, if both the lines are additions (ie start with '+') Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Aditya Srivastava <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: fix unescaped left braceDwaipayan Ray1-1/+1
There is an unescaped left brace in a regex in OPEN_BRACE check. This throws a runtime error when checkpatch is run with --fix flag and the OPEN_BRACE check is executed. Fix it by escaping the left brace. Link: https://lkml.kernel.org/r/[email protected] Fixes: 8d1824780f2f ("checkpatch: add --fix option for a couple OPEN_BRACE misuses") Signed-off-by: Dwaipayan Ray <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: avoid COMMIT_LOG_LONG_LINE warning for signature tagsAditya Srivastava1-2/+2
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: [email protected] 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/[email protected] Signed-off-by: Aditya Srivastava <[email protected]> Acked-by: Joe Perches <[email protected]> Cc: Lukas Bulwahn <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: fix spelling errors and remove repeated wordDwaipayan Ray1-3/+3
Delete repeated word in scripts/checkpatch.pl: "are are" -> "are" Fix typos: "commments" -> "comments" "falsly" -> "falsely" Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dwaipayan Ray <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: improve email parsingDwaipayan Ray1-17/+91
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: <[email protected]> # 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/[email protected]/ Link: https://lore.kernel.org/linux-kernel-mentees/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dwaipayan Ray <[email protected]> Suggested-by: Joe Perches <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: add __alias and __weak to suggested __attribute__ conversionsJoe Perches1-1/+3
Add __alias and __weak to the suggested __attribute__((<foo>)) conversions. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Joe Perches <[email protected]> Cc: Dwaipayan Ray <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: add fix option for GERRIT_CHANGE_IDAditya Srivastava1-2/+5
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 adc311a5bbf6 ("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/[email protected] Signed-off-by: Aditya Srivastava <[email protected]> Acked-by: Joe Perches <[email protected]> Cc: Lukas Bulwahn <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: update __attribute__((section("name"))) quote removalJoe Perches1-32/+15
commit 33def8498fdd ("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...)). [[email protected]: eliminate the separate test below the possible conversions loop] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Joe Perches <[email protected]> Cc: Dwaipayan Ray <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: add a fixer for missing newline at eofTom Rix1-2/+5
Remove the trailing error message from the fixed lines. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Tom Rix <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: extend attributes check to handle more patternsDwaipayan Ray1-38/+71
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/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dwaipayan Ray <[email protected]> Suggested-by: Joe Perches <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: allow --fix removal of unnecessary break statementsJoe Perches1-4/+8
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/[email protected] Signed-off-by: Joe Perches <[email protected]> Cc: Julia Lawall <[email protected]> Cc: Tom Rix <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: prefer static const declarationsJoe Perches1-0/+12
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/[email protected] Signed-off-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: ignore generated CamelCase defines and enum valuesŁukasz Stelmach1-0/+2
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/[email protected] Signed-off-by: Łukasz Stelmach <[email protected]> Suggested-by: Joe Perches <[email protected]> Acked-by: Joe Perches <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: fix false positives in REPEATED_WORD warningAditya Srivastava1-1/+15
Presence of hexadecimal address or symbol results in false warning message by checkpatch.pl. For example, running checkpatch on commit b8ad540dd4e4 ("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 899e5ffbf246 ("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/[email protected] Signed-off-by: Aditya Srivastava <[email protected]> Acked-by: Joe Perches <[email protected]> Cc: Dwaipayan Ray <[email protected]> Cc: Lukas Bulwahn <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15checkpatch: add new exception to repeated word checkDwaipayan Ray1-2/+13
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/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Dwaipayan Ray <[email protected]> Suggested-by: Joe Perches <[email protected]> Suggested-by: Lukas Bulwahn <[email protected]> Acked-by: Joe Perches <[email protected]> Cc: Aditya Srivastava <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/lz4: explicitly support in-place decompressionGao Xiang2-1/+6
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 59daa706fbec ("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] https://github.com/lz4/lz4/commit/33cb8518ac385835cc17be9a770b27b40cd0e15b [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/[email protected] Signed-off-by: Gao Xiang <[email protected]> Reviewed-by: Nick Terrell <[email protected]> Cc: Yann Collet <[email protected]> Cc: Miao Xie <[email protected]> Cc: Chao Yu <[email protected]> Cc: Li Guifu <[email protected]> Cc: Guo Xuenan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib: cleanup kstrto*() usageAlexey Dobriyan2-22/+13
Use proper conversion functions. kstrto*() variants exist for all standard types. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexey Dobriyan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15drivers/misc/lkdtm/lkdtm.h: correct wrong filenames in commentFrancis Laniel1-7/+7
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/[email protected] Signed-off-by: Francis Laniel <[email protected]> Acked-by: Kees Cook <[email protected]> Cc: Daniel Axtens <[email protected]> Cc: Daniel Micay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15drivers/misc/lkdtm: add new file in LKDTM to test fortified strscpyFrancis Laniel5-0/+88
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/[email protected] Signed-off-by: Francis Laniel <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Daniel Axtens <[email protected]> Cc: Daniel Micay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15string.h: add FORTIFY coverage for strscpy()Francis Laniel1-0/+48
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/[email protected] Signed-off-by: Francis Laniel <[email protected]> Acked-by: Kees Cook <[email protected]> Cc: Daniel Axtens <[email protected]> Cc: Daniel Micay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lkdtm: tests for FORTIFY_SOURCEDaniel Axtens3-0/+54
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/[email protected] Signed-off-by: Daniel Axtens <[email protected]> Signed-off-by: Francis Laniel <[email protected]> Suggested-by: Kees Cook <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Daniel Micay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib: string.h: detect intra-object overflow in fortified string functionsDaniel Axtens1-11/+16
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 6974f0c4555e ("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/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Daniel Axtens <[email protected]> Signed-off-by: Francis Laniel <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Daniel Micay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/string: remove unnecessary #undefsNick Desaulniers1-4/+0
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/[email protected] Fixes: 5f074f3e192f ("lib/string.c: implement a basic bcmp") Signed-off-by: Nick Desaulniers <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Yury Norov <[email protected]> Cc: Alexandru Ardelean <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Masahiro Yamada <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15ilog2: improve ilog2 for constant argumentsJakub Jelinek1-1/+2
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. [[email protected]: coding style fixes] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/20201021132718.GB2176@tucnak Signed-off-by: Jakub Jelinek <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Christophe Leroy <[email protected]> Cc: Randy Dunlap <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/cmdline_kunit: add a new test suite for cmdline APIAndy Shevchenko3-0/+112
Test get_option() for a starter which is provided by cmdline.c. [[email protected]: fix warning by constifying cmdline_test_values] [[email protected]: type of expected returned values should be int] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: provide meaningful MODULE_LICENSE()] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Andy Shevchenko <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Vitor Massaru Iha <[email protected]> Cc: Mark Brown <[email protected]> Cc: Brendan Higgins <[email protected]> Cc: David Gow <[email protected]> Cc: Matti Vaittinen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/cmdline: allow NULL to be an output for get_option()Andy Shevchenko1-3/+9
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/[email protected] Signed-off-by: Andy Shevchenko <[email protected]> Cc: Brendan Higgins <[email protected]> Cc: David Gow <[email protected]> Cc: Mark Brown <[email protected]> Cc: Matti Vaittinen <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Vitor Massaru Iha <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/cmdline: fix get_option() for strings starting with hyphenAndy Shevchenko1-1/+7
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/[email protected] Fixes: f68565831e72 ("Import 2.4.0-test2pre3") Signed-off-by: Andy Shevchenko <[email protected]> Cc: Brendan Higgins <[email protected]> Cc: David Gow <[email protected]> Cc: Mark Brown <[email protected]> Cc: Matti Vaittinen <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Vitor Massaru Iha <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/test_lockup.c: minimum fix to get it compiled on PREEMPT_RTSebastian Andrzej Siewior1-0/+16
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/[email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Cc: Konstantin Khlebnikov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/stackdepot.c: use array_size() helper in jhash2()Gustavo A. R. Silva1-2/+2
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 <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/stackdepot.c: use flex_array_size() helper in memcpy()Gustavo A. R. Silva1-1/+1
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 <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/stackdepot.c: replace one-element array with flexible-array memberGustavo A. R. Silva1-3/+2
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/[email protected] Link: https://lore.kernel.org/lkml/5f75876b.x9zdN10esiC0qLHV%[email protected]/ Link: https://lkml.kernel.org/r/2f1e6a17aaa891ad9c58817cf0a10b8ab8894f59.1601565471.git.gustavoars@kernel.org Signed-off-by: Gustavo A. R. Silva <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15lib/test_free_pages.c: add basic progress indicatorsGeert Uytterhoeven1-0/+5
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/[email protected] Signed-off-by: Geert Uytterhoeven <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Matthew Wilcox <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15bitmap: remove unused function declarationMa, Jianpeng1-2/+0
Link: https://lkml.kernel.org/r/BN7PR11MB26097166B6B46387D8A1ABA4FDE30@BN7PR11MB2609.namprd11.prod.outlook.com Fixes: 2afe27c718b6 ("lib/bitmap.c: bitmap_[empty,full]: remove code duplication") Signed-off-by: Jianpeng Ma <[email protected]> Acked-by: Yury Norov <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15include/linux/bitmap.h: convert bitmap_empty() / bitmap_full() to return booleanAndy Shevchenko1-2/+2
There is no need to return int type out of boolean expression. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Andy Shevchenko <[email protected]> Cc: Yury Norov <[email protected]> Cc: Rasmus Villemoes <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15kernel/acct.c: use #elif instead of #end and #elifHui Su1-5/+2
Cleanup: use #elif instead of #end and #elif. Link: https://lkml.kernel.org/r/20201015150736.GA91603@rlk Signed-off-by: Hui Su <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15kernel.h: split out mathematical helpersAndy Shevchenko15-183/+215
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. [[email protected]: fix powerpc build] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Andy Shevchenko <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Trond Myklebust <[email protected]> Cc: Jeff Layton <[email protected]> Cc: Rasmus Villemoes <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15asm-generic: force inlining of get_order() to work around gcc10 poor decisionChristophe Leroy1-1/+1
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 ac7c3e4ff401 ("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 <[email protected]> Reviewed-by: Joel Stanley <[email protected]> Cc: Segher Boessenkool <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Masahiro Yamada <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15fs/proc: make pde_get() return nothingHui Su1-2/+1
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 <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Eric W. Biederman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15proc: fix lookup in /proc/net subdirectories after setns(2)Alexey Dobriyan4-19/+36
Commit 1fde6f21d90f ("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/[email protected] Fixes: 1da4d377f943 ("proc: revalidate misc dentries") Signed-off-by: Alexey Dobriyan <[email protected]> Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15proc: provide details on indirect branch speculationAnand K Mistry2-0/+30
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. [[email protected]: 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 <[email protected]> Cc: Anthony Steinhauser <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Anand K Mistry <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Alexey Gladkov <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Kees Cook <[email protected]> Cc: Mauro Carvalho Chehab <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: NeilBrown <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15procfs: delete duplicated words + other fixesRandy Dunlap2-3/+3
Delete repeated words in fs/proc/. {the, which} where "which which" was changed to "with which". Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Randy Dunlap <[email protected]> Cc: Alexey Dobriyan <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15alpha: replace bogus in_interrupt()Thomas Gleixner1-1/+1
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/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Tested-by: Serge Belyshev <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Matt Turner <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15mm/memory_hotplug: quieting offline operationLaurent Dufour1-1/+1
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/[email protected] Signed-off-by: Laurent Dufour <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Nathan Lynch <[email protected]> Cc: Scott Cheloha <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15mm: fix a race on nr_swap_pagesZhaoyang Huang1-5/+6
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/[email protected] Signed-off-by: Zhaoyang Huang <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2020-12-15Merge branch 'exec-update-lock-for-v5.11' of ↵Linus Torvalds8-43/+44
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
2020-12-15Merge branch 'exec-for-v5.11' of ↵Linus Torvalds19-244/+158
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 ...
2020-12-15Merge branch 'signal-for-v5.11' of ↵Linus Torvalds1-2/+0
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
2020-12-15Merge tag 'close-range-openat2-v5.11' of ↵Linus Torvalds5-11/+122
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
2020-12-15Merge branch 'regset.followup' of ↵Linus Torvalds8-44/+28
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()
2020-12-15Merge branch 'work.epoll' of ↵Linus Torvalds4-429/+305
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 ...