When doing Python programming it is a nice convention to insert the if
statement `if __name__ == "__main__":` before any main code that does
actual functionalities to ensure the code will be executed only as a
script rather than as an imported module. Hence attach the missing
judgement to show_delta.
Link: https://lkml.kernel.org/r/20231013132832.165768-1-2023002089@link.tyut.edu.cn
Signed-off-by: Hu Haowen <2023002089@link.tyut.edu.cn>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__read_mostly predates __ro_after_init. Many variables which are marked
__read_mostly should have been __ro_after_init from day 1.
Also, mark some stuff as "const" and "__init" while I'm at it.
[akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning]
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Test return values before overwriting.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20231009141111.149858-1-artem.chernyshev@red-soft.ru
Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
My original comment lied, output can be "0 A A B 0 0 0\n"
(see comment in the code).
I don't quite understand why
get_mm_counter(mm, MM_FILEPAGES) + get_mm_counter(mm, MM_SHMEMPAGES)
can stay positive but get_mm_counter(mm, MM_ANONPAGES) is always 0 after
everything is unmapped but that's just me.
[adobriyan@gmail.com: more or less rewritten]
Link: https://lkml.kernel.org/r/0721ca69-7bb4-40aa-8d01-0c5f91e5f363@p183
Signed-off-by: Swarup Laxman Kotiaklapudi <swarupkotikalapudi@gmail.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prior to f747e6667e __is_constexpr() was in its only user minmax.h.
That commit moved it to const.h - but that file just defines ULL(x) and
UL(x) so that constants can be defined for .S and .c files.
So apart from the word 'const' it wasn't really a good location. Instead
move the definition to compiler.h just before the similar
is_signed_type() and is_unsigned_type().
This may not be a good long-term home, but the three definitions belong
together.
Link: https://lkml.kernel.org/r/2a6680bbe2e84459816a113730426782@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
As found with Coccinelle[1], add __counted_by for struct gcov_iterator.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Link: https://lkml.kernel.org/r/20230922175220.work.327-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There were some recent attempts [1] [2] to make the K: field less noisy
and its behavior more obvious. Ultimately, a shift in the default
behavior and an associated command line flag is the best choice.
Currently, K: will match keywords found in both patches and files.
Matching content from entire files is (while documented) not obvious
behavior and is usually not wanted by maintainers.
Now only patch content will be matched against unless --keywords-in-file
is also provided as an argument to get_maintainer.
Add the actual keyword matched to the role or rolestats as well.
For instance given the diff below that removes clang:
: diff --git a/drivers/hid/bpf/entrypoints/README b/drivers/hid/bpf/entrypoints/README
: index 147e0d41509f..f88eb19e8ef2 100644
: --- a/drivers/hid/bpf/entrypoints/README
: +++ b/drivers/hid/bpf/entrypoints/README
: @@ -1,4 +1,4 @@
: WARNING:
: If you change "entrypoints.bpf.c" do "make -j" in this directory to rebuild "entrypoints.skel.h".
: -Make sure to have clang 10 installed.
: +Make sure to have 10 installed.
: See Documentation/bpf/bpf_devel_QA.rst
The new role/rolestats output includes ":Keyword:\b(?i:clang|llvm)\b"
$ git diff drivers/hid/bpf/entrypoints/README | .scripts/get_maintainer.pl
Jiri Kosina <jikos@kernel.org> (maintainer:HID CORE LAYER,commit_signer:1/1=100%)
Benjamin Tissoires <benjamin.tissoires@redhat.com> (maintainer:HID CORE LAYER,commit_signer:1/1=100%,authored:1/1=100%,added_lines:4/4=100%)
Nathan Chancellor <nathan@kernel.org> (supporter:CLANG/LLVM BUILD SUPPORT:Keyword:\b(?i:clang|llvm)\b)
Nick Desaulniers <ndesaulniers@google.com> (supporter:CLANG/LLVM BUILD SUPPORT:Keyword:\b(?i:clang|llvm)\b)
Tom Rix <trix@redhat.com> (reviewer:CLANG/LLVM BUILD SUPPORT:Keyword:\b(?i:clang|llvm)\b)
Greg Kroah-Hartman <gregkh@linuxfoundation.org> (commit_signer:1/1=100%)
linux-input@vger.kernel.org (open list:HID CORE LAYER)
linux-kernel@vger.kernel.org (open list)
llvm@lists.linux.dev (open list:CLANG/LLVM BUILD SUPPORT:Keyword:\b(?i:clang|llvm)\b)
Link: https://lore.kernel.org/r/20231004-get_maintainer_change_k-v1-1-ac7ced18306a@google.com
Link: https://lore.kernel.org/all/20230928-get_maintainer_add_d-v2-0-8acb3f394571@google.com
Link: https://lore.kernel.org/all/3dca40b677dd2fef979a5a581a2db91df2c21801.camel@perches.com
Original-patch-by: Justin Stitt <justinstitt@google.com>
Link: https://lkml.kernel.org/r/01fe46f0c58aa8baf92156ae2bdccfb2bf0cb48e.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Justin Stitt <justinstitt@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use while loop instead of infinite loop with "break;".
Also move some variable to the inner scope where they belong.
Link: https://lkml.kernel.org/r/82c8f8e7-8ded-46ca-8857-e60b991d6205@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Save LOC by using dark magic of initialisation instead of memset().
Those buffer aren't passed to userspace directly so padding is not
an issue.
Link: https://lkml.kernel.org/r/3821d3a2-6e10-4629-b0d5-9519d828ab72@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Allow (for example) min(unsigned_var, 20).
The opposite min(signed_var, 20u) is still errored.
Since a comparison between signed and unsigned never makes the unsigned
value negative it is only necessary to adjust the __types_ok() test.
Link: https://lkml.kernel.org/r/633b64e2f39e46bb8234809c5595b8c7@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since 'unsigned char/short' get promoted to 'signed int' it is safe to
compare them against an 'int' value.
Link: https://lkml.kernel.org/r/8732ef5f809c47c28a7be47c938b28d4@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove the extra indentation and align continuation markers.
Link: https://lkml.kernel.org/r/bed41317a05c498ea0209eafbcab45a5@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The type-check in min()/max() is there to stop unexpected results if a
negative value gets converted to a large unsigned value. However it also
rejects 'unsigned int' v 'unsigned long' compares which are common and
never problematc.
Replace the 'same type' check with a 'same signedness' check.
The new test isn't itself a compile time error, so use static_assert() to
report the error and give a meaningful error message.
Due to the way builtin_choose_expr() works detecting the error in the
'non-constant' side (where static_assert() can be used) also detects
errors when the arguments are constant.
Link: https://lkml.kernel.org/r/fe7e6c542e094bfca655abcd323c1c98@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "minmax: Relax type checks in min() and max()", v4.
The min() (etc) functions in minmax.h require that the arguments have
exactly the same types.
However when the type check fails, rather than look at the types and fix
the type of a variable/constant, everyone seems to jump on min_t(). In
reality min_t() ought to be rare - when something unusual is being done,
not normality.
The orginal min() (added in 2.4.9) replaced several inline functions and
included the type - so matched the implicit casting of the function call.
This was renamed min_t() in 2.4.10 and the current min() added. There is
no actual indication that the conversion of negatve values to large
unsigned values has ever been an actual problem.
A quick grep shows 5734 min() and 4597 min_t(). Having the casts on
almost half of the calls shows that something is clearly wrong.
If the wrong type is picked (and it is far too easy to pick the type of
the result instead of the larger input) then significant bits can get
discarded.
Pretty much the worst example is in the derived clamp_val(), consider:
unsigned char x = 200u;
y = clamp_val(x, 10u, 300u);
I also suspect that many of the min_t(u16, ...) are actually wrong. For
example copy_data() in printk_ringbuffer.c contains:
data_size = min_t(u16, buf_size, len);
Here buf_size is 'unsigned int' and len 'u16', pass a 64k buffer (can you
prove that doesn't happen?) and no data is returned. Apparantly it did -
and has since been fixed.
The only reason that most of the min_t() are 'fine' is that pretty much
all the values in the kernel are between 0 and INT_MAX.
Patch 1 adds umin(), this uses integer promotions to convert both
arguments to 'unsigned long long'. It can be used to compare a signed
type that is known to contain a non-negative value with an unsigned type.
The compiler typically optimises it all away. Added first so that it can
be referred to in patch 2.
Patch 2 replaces the 'same type' check with a 'same signedness' one. This
makes min(unsigned_int_var, sizeof()) be ok. The error message is also
improved and will contain the expanded form of both arguments (useful for
seeing how constants are defined).
Patch 3 just fixes some whitespace.
Patch 4 allows comparisons of 'unsigned char' and 'unsigned short' to
signed types. The integer promotion rules convert them both to 'signed
int' prior to the comparison so they can never cause a negative value be
converted to a large positive one.
Patch 5 (rewritted for v4) allows comparisons of unsigned values against
non-negative constant integer expressions. This makes
min(unsigned_int_var, 4) be ok.
The only common case that is still errored is the comparison of signed
values against unsigned constant integer expressions below __INT_MAX__.
Typcally min(int_val, sizeof (foo)), the real fix for this is casting the
constant: min(int_var, (int)sizeof (foo)).
With all the patches applied pretty much all the min_t() could be replaced
by min(), and most of the rest by umin(). However they all need careful
inspection due to code like:
sz = min_t(unsigned char, sz - 1, LIM - 1) + 1;
which converts 0 to LIM.
This patch (of 6):
umin() and umax() can be used when min()/max() errors a signed v unsigned
compare when the signed value is known to be non-negative.
Unlike min_t(some_unsigned_type, a, b) umin() will never mask off high
bits if an inappropriate type is selected.
The '+ 0u + 0ul + 0ull' may look strange.
The '+ 0u' is needed for 'signed int' on 64bit systems.
The '+ 0ul' is needed for 'signed long' on 32bit systems.
The '+ 0ull' is needed for 'signed long long'.
Link: https://lkml.kernel.org/r/b97faef60ad24922b530241c5d7c933c@AcuMS.aculab.com
Link: https://lkml.kernel.org/r/41d93ca827a248698ec64bf57e0c05a5@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ucounts is assigned first, so it does not need to initialize the
assignment.
Link: https://lkml.kernel.org/r/20230926022410.4280-1-kunyu@nfschina.com
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
As found with Coccinelle[1], add __counted_by for struct ocfs2_replay_map.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Link: https://lkml.kernel.org/r/20230922174925.work.293-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Extract nifty FILE_LINE useful for printk style debugging:
printk("%s\n", FILE_LINE);
It should not be used en mass probably because __FILE__ string literals
can be merged while FILE_LINE's won't. But for debugging it is what
the doctor ordered.
Don't add leading and trailing underscores, they're painful to type.
Trust me, I've tried both versions.
Link: https://lkml.kernel.org/r/ebf12ac4-5a61-4b12-b8b0-1253eb371332@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
So far, nobody calls functions parse_crashkernel_high() and
parse_crashkernel_low(), remove both of them.
Link: https://lkml.kernel.org/r/20230914033142.676708-10-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With the help of newly changed function parse_crashkernel() and generic
reserve_crashkernel_generic(), crashkernel reservation can be simplified
by steps:
1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;
2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
reserve_crashkernel_generic();
3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
arch/riscv/Kconfig.
The old reserve_crashkernel_low() and reserve_crashkernel() can be
removed.
[chenjiahao16@huawei.com: fix crashkernel reserving problem on RISC-V]
Link: https://lkml.kernel.org/r/20230925024333.730964-1-chenjiahao16@huawei.com
Link: https://lkml.kernel.org/r/20230914033142.676708-9-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With the help of newly changed function parse_crashkernel() and generic
reserve_crashkernel_generic(), crashkernel reservation can be simplified
by steps:
1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;
2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
reserve_crashkernel_generic();
3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
arch/arm64/Kconfig.
The old reserve_crashkernel_low() and reserve_crashkernel() can be
removed.
Link: https://lkml.kernel.org/r/20230914033142.676708-8-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With the help of newly changed function parse_crashkernel() and generic
reserve_crashkernel_generic(), crashkernel reservation can be simplified
by steps:
1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;
2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
reserve_crashkernel_generic(), and do the ARCH specific work if
needed.
3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
arch/x86/Kconfig.
When adding DEFAULT_CRASH_KERNEL_LOW_SIZE, add crash_low_size_default() to
calculate crashkernel low memory because x86_64 has special requirement.
The old reserve_crashkernel_low() and reserve_crashkernel() can be
removed.
[bhe@redhat.com: move crash_low_size_default() code into <asm/crash_core.h>]
Link: https://lkml.kernel.org/r/ZQpeAjOmuMJBFw1/@MiWiFi-R3L-srv
Link: https://lkml.kernel.org/r/20230914033142.676708-7-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Both crashk_res and crashk_low_res are used to mark the reserved
crashkernel regions in iomem_resource tree. And later the generic
crashkernel resrvation will be added into crash_core.c. So move
crashk_res and crashk_low_res definition into crash_core.c to avoid
compiling error if CONFIG_CRASH_CORE=on while CONFIG_KEXEC_CORE is unset.
Meanwhile include <asm/crash_core.h> in <linux/crash_core.h> if generic
reservation is needed. In that case, <asm/crash_core.h> need be added by
ARCH. In asm/crash_core.h, ARCH can provide its own macro definitions to
override macros in <linux/crash_core.h> if needed. Wrap the including
into CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope to
avoid compiling error in other ARCH-es which don't take the generic
reservation way yet.
Link: https://lkml.kernel.org/r/20230914033142.676708-6-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In architecture like x86_64, arm64 and riscv, they have vast virtual
address space and usually have huge physical memory RAM. Their
crashkernel reservation doesn't have to be limited under 4G RAM, but can
be extended to the whole physical memory via crashkernel=,high support.
Now add function reserve_crashkernel_generic() to reserve crashkernel
memory if users specify any case of kernel pamameters, like
crashkernel=xM[@offset] or crashkernel=,high|low.
This is preparation to simplify code of crashkernel=,high support in
architecutures.
Link: https://lkml.kernel.org/r/20230914033142.676708-5-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now parse_crashkernel() is a real entry point for all kinds of crahskernel
parsing on any architecture.
And wrap the crahskernel=,high|low handling inside
CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope.
Link: https://lkml.kernel.org/r/20230914033142.676708-4-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add two parameters 'low_size' and 'high' to function parse_crashkernel(),
later crashkernel=,high|low parsing will be added. Make adjustments in
all call sites of parse_crashkernel() in arch.
Link: https://lkml.kernel.org/r/20230914033142.676708-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kdump: use generic functions to simplify crashkernel
reservation in arch", v3.
In the current arm64, crashkernel=,high support has been finished after
several rounds of posting and careful reviewing. The code in arm64 which
parses crashkernel kernel parameters firstly, then reserve memory can be a
good example for other ARCH to refer to.
Whereas in x86_64, the code mixing crashkernel parameter parsing and
memory reserving is twisted, and looks messy. Refactoring the code to
make it more readable maintainable is necessary.
Here, firstly abstract the crashkernel parameter parsing code into
parse_crashkernel() to make it be able to parse crashkernel=,high|low.
Then abstract the crashkernel memory reserving code into a generic
function reserve_crashkernel_generic(). Finally, in ARCH which
crashkernel=,high support is needed, a simple arch_reserve_crashkernel()
can be added to call above two functions. This can remove the duplicated
implmentation code in each ARCH, like arm64, x86_64 and riscv.
crashkernel=512M,high
crashkernel=512M,high crashkernel=256M,low
crashkernel=512M,high crashkernel=0M,low
crashkernel=0M,high crashkernel=256M,low
crashkernel=512M
crashkernel=512M@0x4f000000
crashkernel=1G-4G:256M,4G-64G:320M,64G-:576M
crashkernel=0M
This patch (of 9):
In all call sites of __parse_crashkernel(), the parameter 'name' is
hardcoded as "crashkernel=". So remove the unnecessary parameter 'name',
add local varibale 'name' inside __parse_crashkernel() instead.
Link: https://lkml.kernel.org/r/20230914033142.676708-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20230914033142.676708-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
strlcpy() reads the entire source buffer first. This read may exceed the
destination size limit. This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1]. In an effort
to remove strlcpy() completely [2], replace strlcpy() here with
sysfs_emit().
Direct replacement is safe here since its ok for `kernel_param_ops.get()`
to return -errno [3].
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
[3] https://elixir.bootlin.com/linux/v6.5/source/include/linux/moduleparam.h#L52
Link: https://lkml.kernel.org/r/20230831193827.1528867-1-azeemshaikh38@gmail.com
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
BUILD_BUG_ON*() macros are defined in build_bug.h. Include it. Replace
compiler_types.h by compiler.h, which provides the former, to have a
definition of the __UNIQUE_ID().
Link: https://lkml.kernel.org/r/20230912092355.79280-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Herve Codina <herve.codina@bootlin.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
commit 95846ecf9dac("pid: replace pid bitmap implementation with IDR API")
removes 'last_pid' element, and use the idr_get_cursor-idr_set_cursor pair
to set the value of idr, so useless comments should be removed.
Link: https://lkml.kernel.org/r/tencent_157A2A1CAF19A3F5885F0687426159A19708@qq.com
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It appears that compiler_types.h already have an implementation of the
__unconst_integer_typeof() called __unqual_scalar_typeof(). Use it
instead of the copy.
Link: https://lkml.kernel.org/r/20230911154913.4176033-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a kthread_stop_put() helper that stops a thread and puts its task
struct. Use it to replace the various instances of kthread_stop()
followed by put_task_struct().
Remove the kthread_stop_put() macro in usbip that is similar but doesn't
return the result of kthread_stop().
[agruenba@redhat.com: fix kerneldoc comment]
Link: https://lkml.kernel.org/r/20230911111730.2565537-1-agruenba@redhat.com
[akpm@linux-foundation.org: document kthread_stop_put()'s argument]
Link: https://lkml.kernel.org/r/20230907234048.2499820-1-agruenba@redhat.com
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
do/while_each_thread should be avoided when possible.
Plus I _think_ this change allows to avoid lock_task_sighand() but I am
not sure, I forgot everything about taskstats. In any case, this code
does not look right in that the same thread can be accounted twice:
taskstats_exit() can account the exiting thread in signal->stats and drop
->siglock but this thread is still on the thread-group list, so
lock_task_sighand() can't help.
Link: https://lkml.kernel.org/r/20230909214951.GA24274@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
do/while_each_thread should be avoided when possible.
Plus this change allows to avoid lock_task_sighand(), we can use rcu
and/or sig->stats_lock instead.
Link: https://lkml.kernel.org/r/20230909172629.GA20454@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
No functional changes, cleanup/preparation.
Link: https://lkml.kernel.org/r/20230909172554.GA20441@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
do/while_each_thread should be avoided when possible.
Link: https://lkml.kernel.org/r/20230909164537.GA11633@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
do/while_each_thread should be avoided when possible.
Link: https://lkml.kernel.org/r/20230909164501.GA11581@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use DEFINE_SHOW_STORE_ATTRIBUTE() helper for read-write file to reduce some
duplicated code.
Link: https://lkml.kernel.org/r/20230905024835.43219-4-yangxingui@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Co-developed-by: Xingui Yang <yangxingui@huawei.com>
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Cc: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use DEFINE_SHOW_STORE_ATTRIBUTE() helper for read-write file to reduce some
duplicated code.
Link: https://lkml.kernel.org/r/20230905024835.43219-3-yangxingui@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Co-developed-by: Xingui Yang <yangxingui@huawei.com>
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Cc: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Add helper macro DEFINE_SHOW_STORE_ATTRIBUTE() at
seq_file.c", v6.
We already own DEFINE_SHOW_ATTRIBUTE() helper macro for defining attribute
for read-only file, but we found many of drivers also want a helper macro
for read-write file too.
So we add this helper macro to reduce duplicated code.
This patch (of 3):
We already own DEFINE_SHOW_ATTRIBUTE() helper macro for defining attribute
for read-only file, but many of drivers want a helper macro for read-write
file too.
So we add DEFINE_SHOW_STORE_ATTRIBUTE() helper to reduce duplicated code.
Link: https://lkml.kernel.org/r/20230905024835.43219-1-yangxingui@huawei.com
Link: https://lkml.kernel.org/r/20230905024835.43219-2-yangxingui@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Co-developed-by: Xingui Yang <yangxingui@huawei.com>
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Cc: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use atomic_try_cmpxchg instead of atomic_cmpxchg (*ptr, old, new) == old
in panic() and nmi_panic(). x86 CMPXCHG instruction returns success in ZF
flag, so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).
Also, rename cpu variable to this_cpu in nmi_panic() and try to unify
logic flow between panic() and nmi_panic().
No functional change intended.
[ubizjak@gmail.com: clean up if/else block]
Link: https://lkml.kernel.org/r/20230906191200.68707-1-ubizjak@gmail.com
Link: https://lkml.kernel.org/r/20230904152230.9227-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
No need to calculate/check the "success" variable, we can kill it and update
retval in the main loop unless it is zero.
Link: https://lkml.kernel.org/r/20230823171455.GA12188@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The last user was removed by the previous patch.
Link: https://lkml.kernel.org/r/20230826111409.GA23243@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kill task_struct->thread_group".
This patch (of 2):
It could use list_is_singular() but this way it is cheaper. Plus the
thread_group_leader() check makes it clear that thread_group_empty() can
only return true if p is a group leader. This was not immediately obvious
before this patch.
task_struct->thread_group no longer has users, it can die.
Link: https://lkml.kernel.org/r/20230826111200.GA22982@redhat.com
Link: https://lkml.kernel.org/r/20230826111406.GA23238@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This relies on fact that group leader is always the 1st entry in the
signal->thread_head list.
With or without this change, if the lockless next_thread(last_thread)
races with exec it can return the old or the new leader.
We are almost ready to kill task->thread_group, after this change its
only user is thread_group_empty().
Link: https://lkml.kernel.org/r/20230824143201.GB31222@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "introduce __next_thread(), change next_thread()".
After commit dce8f8ed1d ("document while_each_thread(), change
first_tid() to use for_each_thread()") + this series
1. We have only one lockless user of next_thread(), task_group_seq_get_next().
I think it should be changed too.
2. We have only one user of task_struct->thread_group, thread_group_empty().
The next patches will change thread_group_empty() and kill ->thread_group.
This patch (of 2):
next_tid(start) does:
rcu_read_lock();
if (pid_alive(start)) {
pos = next_thread(start);
if (thread_group_leader(pos))
pos = NULL;
else
get_task_struct(pos);
it should return pos = NULL when next_thread() wraps to the 1st thread
in the thread group, group leader, and the thread_group_leader() check
tries to detect this case.
But this can race with exec. To simplify, suppose we have a main thread
M and a single sub-thread T, next_tid(T) should return NULL.
Now suppose that T execs. If next_tid(T) is called after T changes the
leadership and before it does release_task() which removes the old leader
from list, then next_thread() returns M and thread_group_leader(M) = F.
Lockless use of next_thread() should be avoided. After this change only
task_group_seq_get_next() does this, and I believe it should be changed
as well.
Link: https://lkml.kernel.org/r/20230824143112.GA31208@redhat.com
Link: https://lkml.kernel.org/r/20230824143142.GA31222@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
global bitmap is a cluster allocator,so after we traverse the global
bitmap and finished the fstrim,the trimmed range should be 'trimmed *
clustersize'.otherwise,the trimmed range printed by 'fstrim -v' is not as
expected.
Link: https://lkml.kernel.org/r/20230828051741.204577-1-yuanhengzhang1214@gmail.com
Signed-off-by: Yuanheng Zhang <yuanhengzhang1214@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
commit 6f33d58794 ("__UNIQUE_ID()")
added a fallback definition of __UNIQUE_ID because gcc 4.2 and older did
not support __COUNTER__.
Also, this commit is effectively a revert of
commit b41c29b052 ("Kbuild: provide a __UNIQUE_ID for clang")
which mentions clang 2.6+ supporting __COUNTER__.
Documentation/process/changes.rst currently lists the minimum supported
version of these compilers as:
- gcc: 5.1
- clang: 11.0.0
It should be safe to say that __COUNTER__ is well supported by this
point.
Link: https://lkml.kernel.org/r/20230831-unique_id-v1-1-28bacd18eb1d@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Michal rarek <mmarek@suse.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Paul Russel <rusty@rustcorp.com.au>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After move of Documentation/s390 to Documentation/arch/s390
Link: https://lkml.kernel.org/r/20230825013102.1487979-1-costa.shul@redhat.com
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Eric DeVolder <eric.devolder@oracle.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
