- 01 Dec, 2022 6 commits
-
-
Stephen Brennan authored
Though vmcoreinfo is intended to be small, at just one page, useful information is still added to it, so we risk running out of space. Currently there is no runtime check to see whether the vmcoreinfo buffer has been exhausted. Add a warning for this case. Currently, my static checking tool[1] indicates that a good upper bound for vmcoreinfo size is currently 3415 bytes, but the best time to add warnings is before the risk becomes too high. [1] https://github.com/brenns10/kernel_stuff/blob/master/vmcoreinfosize/vmcoreinfosize.py Link: https://lkml.kernel.org/r/20221027205008.312534-1-stephen.s.brennan@oracle.comSigned-off-by:
Stephen Brennan <stephen.s.brennan@oracle.com> Acked-by:
Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
-
Liao Chang authored
These array allocator family are sometimes misused with the first and second arguments switched. Same issue with calloc, kvcalloc, kvmalloc_array etc. Bleat if sizeof is the first argument. Link: https://lore.kernel.org/lkml/5374345c-7973-6a3c-d559-73bf4ac15079@redhat.com/ Link: https://lkml.kernel.org/r/20221104070523.60296-1-liaochang1@huawei.comSigned-off-by:
Liao Chang <liaochang1@huawei.com> Acked-by:
Joe Perches <joe@perches.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Andy Whitcroft <apw@canonical.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
-
Jason A. Donenfeld authored
On some platforms, `char` is unsigned, but this driver, for the most part, assumed it was signed. In other places, it uses `char` to mean an unsigned number, but only in cases when the values are small. And in still other places, `char` is used as a boolean. Put an end to this confusion by declaring explicit types, depending on the context. Link: https://lkml.kernel.org/r/20221019155541.3410813-1-Jason@zx2c4.comSigned-off-by:
Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by:
-
Akinobu Mita authored
The simple attribute files do not accept a negative value since the commit 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()"), so we have to use a 64-bit value to write a negative value for a debugfs file created by debugfs_create_atomic_t(). This restores the previous behaviour by introducing DEFINE_DEBUGFS_ATTRIBUTE_SIGNED for a signed value. Link: https://lkml.kernel.org/r/20220919172418.45257-4-akinobu.mita@gmail.com Fixes: 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by:
Akinobu Mita <akinobu.mita@gmail.com> Reported-by:
Zhao Gongyi <zhaogongyi@huawei.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Wei Yongjun <weiyongjun1@huawei.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by:
-
Akinobu Mita authored
The simple attribute files do not accept a negative value since the commit 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()"). This restores the previous behaviour by using newly introduced DEFINE_SIMPLE_ATTRIBUTE_SIGNED instead of DEFINE_SIMPLE_ATTRIBUTE. Link: https://lkml.kernel.org/r/20220919172418.45257-3-akinobu.mita@gmail.com Fixes: 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by:
-
Akinobu Mita authored
Patch series "fix error when writing negative value to simple attribute files". The simple attribute files do not accept a negative value since the commit 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()"), but some attribute files want to accept a negative value. This patch (of 3): The simple attribute files do not accept a negative value since the commit 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()"), so we have to use a 64-bit value to write a negative value. This adds DEFINE_SIMPLE_ATTRIBUTE_SIGNED for a signed value. Link: https://lkml.kernel.org/r/20220919172418.45257-1-akinobu.mita@gmail.com Link: https://lkml.kernel.org/r/20220919172418.45257-2-akinobu.mita@gmail.com Fixes: 488dac0c ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by:
-
- 18 Nov, 2022 34 commits
-
-
Colin Ian King authored
Some of the more common spelling mistakes and typos that I've found while fixing up spelling mistakes in the kernel in the past year. Link: https://lkml.kernel.org/r/20221108110712.114611-1-colin.i.king@gmail.comSigned-off-by:
Colin Ian King <colin.i.king@gmail.com> Signed-off-by:
-
Uros Bizjak authored
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in task_numa_work. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). No functional change intended. Link: https://lkml.kernel.org/r/20220822173956.82525-1-ubizjak@gmail.comSigned-off-by:
Uros Bizjak <ubizjak@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by:
-
YueHaibing authored
'size' is unsigned, it never less than zero. Link: https://lkml.kernel.org/r/20221105110611.28920-1-yuehaibing@huawei.com Fixes: 6c26df84 ("selftests: cgroup: return -errno from cg_read()/cg_write() on failure") Signed-off-by:
YueHaibing <yuehaibing@huawei.com> Reviewed-by:
Yosry Ahmed <yosryahmed@google.com> Acked-by:
Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by:
Kamalesh Babulal <kamalesh.babulal@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: zefan li <lizefan.x@bytedance.com> Signed-off-by:
-
Zhao Gongyi authored
Add local_config.h and local_config.mk to .gitignore to avoid accidentally checking it in. Link: https://lkml.kernel.org/r/20221103005754.205420-1-zhaogongyi@huawei.comSigned-off-by:
-
Baokun Li authored
When squashfs_read_table() returns an error or `sb->s_magic != SQUASHFS_MAGIC`, enters the error branch and calls msblk->thread_ops->destroy(msblk) to destroy msblk. However, msblk->thread_ops has not been initialized. Therefore, the following problem is triggered: ================================================================== BUG: KASAN: null-ptr-deref in squashfs_fill_super+0xe7a/0x13b0 Read of size 8 at addr 0000000000000008 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc3-next-20221031 #367 Call Trace: <TASK> dump_stack_lvl+0x73/0x9f print_report+0x743/0x759 kasan_report+0xc0/0x120 __asan_load8+0xd3/0x140 squashfs_fill_super+0xe7a/0x13b0 get_tree_bdev+0x27b/0x450 squashfs_get_tree+0x19/0x30 vfs_get_tree+0x49/0x150 path_mount+0xaae/0x1350 init_mount+0xad/0x100 do_mount_root+0xbc/0x1d0 mount_block_root+0x173/0x316 mount_root+0x223/0x236 prepare_namespace+0x1eb/0x237 kernel_init_freeable+0x528/0x576 kernel_init+0x29/0x250 ret_from_fork+0x1f/0x30 </TASK> ================================================================== To solve this issue, msblk->thread_ops is initialized immediately after msblk is assigned a value. Link: https://lkml.kernel.org/r/20221101073343.3961562-1-libaokun1@huawei.com Fixes: b0645770d3c7 ("squashfs: add the mount parameter theads=<single|multi|percpu>") Signed-off-by:
Baokun Li <libaokun1@huawei.com> Reviewed-by:
Xiaoming Ni <nixiaoming@huawei.com> Reviewed-by:
Phillip Lougher <phillip@squashfs.org.uk> Cc: Yu Kuai <yukuai3@huawei.com> Cc: Zhang Yi <yi.zhang@huawei.com> Signed-off-by:
-
Shang XiaoJing authored
ocfs2_table_header should be free in ocfs2_stack_glue_init() if ocfs2_sysfs_init() failed, otherwise kmemleak will report memleak. BUG: memory leak unreferenced object 0xffff88810eeb5800 (size 128): comm "modprobe", pid 4507, jiffies 4296182506 (age 55.888s) hex dump (first 32 bytes): c0 40 14 a0 ff ff ff ff 00 00 00 00 01 00 00 00 .@.............. 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000001e59e1cd>] __register_sysctl_table+0xca/0xef0 [<00000000c04f70f7>] 0xffffffffa0050037 [<000000001bd12912>] do_one_initcall+0xdb/0x480 [<0000000064f766c9>] do_init_module+0x1cf/0x680 [<000000002ba52db0>] load_module+0x6441/0x6f20 [<000000009772580d>] __do_sys_finit_module+0x12f/0x1c0 [<00000000380c1f22>] do_syscall_64+0x3f/0x90 [<000000004cf473bc>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Link: https://lkml.kernel.org/r/41651ca1-432a-db34-eb97-d35744559de1@linux.alibaba.com Fixes: 3878f110 ("ocfs2: Move the hb_ctl_path sysctl into the stack glue.") Signed-off-by:Shang XiaoJing <shangxiaojing@huawei.com> 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:
-
Xiongfeng Wang authored
Drop the following unused variables inherited from getdelays.c: 'aggr_len', 'len2', 'cmd_type', 'tid', 'containerset', 'containerpath' and 'sigset'. Link: https://lkml.kernel.org/r/20221031091557.192180-1-wangxiongfeng2@huawei.comSigned-off-by:
Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: "Dr. Thomas Orgis" <thomas.orgis@uni-hamburg.de> Cc: Ismael Luceno <ismael@iodev.co.uk> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by:
-
Tetsuo Handa authored
Like commit c4f135d6 ("workqueue: Wrap flush_workqueue() using a macro") says, flush_scheduled_work() is dangerous and will be forbidden. We are on the way for removing all flush_scheduled_work() callers from the kernel, and this patch is for removing flush_scheduled_work() call from tsi721 driver. Since "struct tsi721_device" is per a device struct, I assume that tsi721_remove() needs to wait for only two works associated with that device. Therefore, wait for only these works using flush_work(). Link: https://lkml.kernel.org/r/0e8a2023-7526-f03a-f520-efafbb0ef45c@I-love.SAKURA.ne.jpSigned-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alexandre Bounine <alex.bou9@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Matt Porter <mporter@kernel.crashing.org> Signed-off-by:
-
Gaosheng Cui authored
Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in lib/fonts/fonts.c:139:20 left shift of 1 by 31 places cannot be represented in type 'int' <TASK> dump_stack_lvl+0x7d/0xa5 dump_stack+0x15/0x1b ubsan_epilogue+0xe/0x4e __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c get_default_font+0x1c7/0x1f0 fbcon_startup+0x347/0x3a0 do_take_over_console+0xce/0x270 do_fbcon_takeover+0xa1/0x170 do_fb_registered+0x2a8/0x340 fbcon_fb_registered+0x47/0xe0 register_framebuffer+0x294/0x4a0 __drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper] drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper] drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper] drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper] bochs_pci_probe+0x6ca/0x772 [bochs] local_pci_probe+0x4d/0xb0 pci_device_probe+0x119/0x320 really_probe+0x181/0x550 __driver_probe_device+0xc6/0x220 driver_probe_device+0x32/0x100 __driver_attach+0x195/0x200 bus_for_each_dev+0xbb/0x120 driver_attach+0x27/0x30 bus_add_driver+0x22e/0x2f0 driver_register+0xa9/0x190 __pci_register_driver+0x90/0xa0 bochs_pci_driver_init+0x52/0x1000 [bochs] do_one_initcall+0x76/0x430 do_init_module+0x61/0x28a load_module+0x1f82/0x2e50 __do_sys_finit_module+0xf8/0x190 __x64_sys_finit_module+0x23/0x30 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> Link: https://lkml.kernel.org/r/20221031113829.4183153-1-cuigaosheng1@huawei.com Fixes: c81f717c ("fbcon: Fix typo and bogus logic in get_default_font") Signed-off-by:
Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by:
-
Xiaoming Ni authored
The maximum number of threads in the decompressor_multi.c file is fixed and cannot be adjusted according to user needs. Therefore, the mount parameter needs to be added to allow users to configure the number of threads as required. The upper limit is num_online_cpus() * 2. Link: https://lkml.kernel.org/r/20221019030930.130456-3-nixiaoming@huawei.comSigned-off-by:
-
Xiaoming Ni authored
Patch series 'squashfs: Add the mount parameter "threads="'. Currently, Squashfs supports multiple decompressor parallel modes. However, this mode can be configured only during kernel building and does not support flexible selection during runtime. In the current patch set, the mount parameter "threads=" is added to allow users to select the parallel decompressor mode and configure the number of decompressors when mounting a file system. "threads=<single|multi|percpu|1|2|3|...>" The upper limit is num_online_cpus() * 2. This patch (of 2): Squashfs supports three decompression concurrency modes: Single-thread mode: concurrent reads are blocked and the memory overhead is small. Multi-thread mode/percpu mode: reduces concurrent read blocking but increases memory overhead. The corresponding schema must be fixed at compile time. During mounting, the concurrent decompression mode cannot be adjusted based on file read blocking. The mount parameter theads=<single|multi|percpu> is added to select the concurrent decompression mode of a single SquashFS file system image. Link: https://lkml.kernel.org/r/20221019030930.130456-1-nixiaoming@huawei.com Link: https://lkml.kernel.org/r/20221019030930.130456-2-nixiaoming@huawei.comSigned-off-by:
-
XU pengfei authored
Remove unnecessary void* type casting. Link: https://lkml.kernel.org/r/20221026080517.3221-1-xupengfei@nfschina.comSigned-off-by:
XU pengfei <xupengfei@nfschina.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Disseldorp <ddiss@suse.de> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Martin Wilck <mwilck@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: wuchi <wuchi.zero@gmail.com> Signed-off-by:
-
Ryusuke Konishi authored
If field s_log_block_size of superblock data is corrupted and too large, init_nilfs() and load_nilfs() still can trigger a shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn is set): shift exponent 38973 is too large for 32-bit type 'int' Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 ubsan_epilogue+0xb/0x50 __ubsan_handle_shift_out_of_bounds.cold.12+0x17b/0x1f5 init_nilfs.cold.11+0x18/0x1d [nilfs2] nilfs_mount+0x9b5/0x12b0 [nilfs2] ... This fixes the issue by adding and using a new helper function for getting block size with sanity check. Link: https://lkml.kernel.org/r/20221027044306.42774-3-konishi.ryusuke@gmail.comSigned-off-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by:
-
Ryusuke Konishi authored
Patch series "nilfs2: fix UBSAN shift-out-of-bounds warnings on mount time". The first patch fixes a bug reported by syzbot, and the second one fixes the remaining bug of the same kind. Although they are triggered by the same super block data anomaly, I divided it into the above two because the details of the issues and how to fix it are different. Both are required to eliminate the shift-out-of-bounds issues at mount time. This patch (of 2): If the block size exponent information written in an on-disk superblock is corrupted, nilfs_sb2_bad_offset helper function can trigger shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn is set): shift exponent 38983 is too large for 64-bit type 'unsigned long long' Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:151 [inline] __ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322 nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline] nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523 init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577 nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047 nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317 ... In addition, since nilfs_sb2_bad_offset() performs multiplication without considering the upper bound, the computation may overflow if the disk layout parameters are not normal. This fixes these issues by inserting preliminary sanity checks for those parameters and by converting the comparison from one involving multiplication and left bit-shifting to one using division and right bit-shifting. Link: https://lkml.kernel.org/r/20221027044306.42774-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20221027044306.42774-2-konishi.ryusuke@gmail.comSigned-off-by:
-
Stanislaw Gruszka authored
Do not report errors like below: ./scripts/checkpatch.pl -f drivers/net/wireless/ath/ath10k/wmi.h ERROR: Macros with complex values should be enclosed in parentheses +#define C2S(x) case x: return #x since many "case ..." macros are already used by some in-kernel drivers. Link: https://lkml.kernel.org/r/20221027134334.164301-1-stf_xl@wp.plSigned-off-by:
Stanislaw Gruszka <stf_xl@wp.pl> Acked-by:
-
Alexey Dobriyan authored
syscall(3) returns -1 and sets errno on error, unlike "syscall" instruction. Systems which have <= 32/64 CPUs are unaffected. Test won't bounce to all CPUs before completing if there are more of them. Link: https://lkml.kernel.org/r/Y1bUiT7VRXlXPQa1@p183 Fixes: 1f5bd054 ("proc: selftests: test /proc/uptime") Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
-
Bjorn Helgaas authored
Remove unused __SLOW_DOWN_IO and SLOW_DOWN_IO definitions. Link: https://lkml.kernel.org/r/20221014001911.3342485-3-helgaas@kernel.orgSigned-off-by:
Bjorn Helgaas <bhelgaas@google.com> Signed-off-by:
-
Gaosheng Cui authored
flush_register_stack() and invalidate_stacked_regs() have been removed since commit 0aeaf6b3 ("ia64/kprobes: Remove jprobe implementation"), so remove them. Link: https://lkml.kernel.org/r/20220914124707.1483471-1-cuigaosheng1@huawei.comSigned-off-by:
-
ye xingchen authored
Avoid typecasts that are needed for IS_ERR() and use IS_ERR_VALUE() instead. Link: https://lkml.kernel.org/r/20221020113004.400031-1-ye.xingchen@zte.com.cnSigned-off-by:
ye xingchen <ye.xingchen@zte.com.cn> Signed-off-by:
Sergei Trofimovich <slyich@gmail.com> Signed-off-by:
-
Alexey Dobriyan authored
Most /proc files don't have length (in fstat sense). This leads to inefficiencies when reading such files with APIs commonly found in modern programming languages. They open file, then fstat descriptor, get st_size == 0 and either assume file is empty or start reading without knowing target size. cat(1) does OK because it uses large enough buffer by default. But naive programs copy-pasted from SO aren't: let mut f = std::fs::File::open("/proc/cmdline").unwrap(); let mut buf: Vec<u8> = Vec::new(); f.read_to_end(&mut buf).unwrap(); will result in openat(AT_FDCWD, "/proc/cmdline", O_RDONLY|O_CLOEXEC) = 3 statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address) statx(3, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0444, stx_size=0, ...}) = 0 lseek(3, 0, SEEK_CUR) = 0 read(3, "BOOT_IMAGE=(hd3,gpt2)/vmlinuz-5.", 32) = 32 read(3, "19.6-100.fc35.x86_64 root=/dev/m", 32) = 32 read(3, "apper/fedora_localhost--live-roo"..., 64) = 64 read(3, "ocalhost--live-swap rd.lvm.lv=fe"..., 128) = 116 read(3, "", 12) open/stat is OK, lseek looks silly but there are 3 unnecessary reads because Rust starts with 32 bytes per Vec<u8> and grows from there. In case of /proc/cmdline, the length is known precisely. Make variables readonly while I'm at it. P.S.: I tried to scp /proc/cpuinfo today and got empty file but this is separate story. Link: https://lkml.kernel.org/r/YxoywlbM73JJN3r+@localhost.localdomainSigned-off-by: -
Bjorn Helgaas authored
The lkml.org, marc.info, spinics.net, etc archives are not quite as useful as lore.kernel.org because they use different styles, add advertising, and may disappear in the future. The lore archives are more consistent and more likely to stick around, so prefer https://lore.kernel.org URLs when they exist. [bhelgaas@google.com: only warn if we see "http" before the archive hostname] Link: https://lkml.kernel.org/r/20221114224315.GA939630@bhelgaas Link: https://lkml.kernel.org/r/20221019202843.40810-1-helgaas@kernel.orgSigned-off-by:
Peter Collingbourne <pcc@google.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> # build-tested Cc: Joe Perches <joe@perches.com> Signed-off-by:
-
Ivan Babrou authored
Many monitoring tools include open file count as a metric. Currently the only way to get this number is to enumerate the files in /proc/pid/fd. The problem with the current approach is that it does many things people generally don't care about when they need one number for a metric. In our tests for cadvisor, which reports open file counts per cgroup, we observed that reading the number of open files is slow. Out of 35.23% of CPU time spent in `proc_readfd_common`, we see 29.43% spent in `proc_fill_cache`, which is responsible for filling dentry info. Some of this extra time is spinlock contention, but it's a contention for the lock we don't want to take to begin with. We considered putting the number of open files in /proc/pid/status. Unfortunately, counting the number of fds involves iterating the open_files bitmap, which has a linear complexity in proportion with the number of open files (bitmap slots really, but it's close). We don't want to make /proc/pid/status any slower, so instead we put this info in /proc/pid/fd as a size member of the stat syscall result. Previously the reported number was zero, so there's very little risk of breaking anything, while still providing a somewhat logical way to count the open files with a fallback if it's zero. RFC for this patch included iterating open fds under RCU. Thanks to Frank Hofmann for the suggestion to use the bitmap instead. Previously: ``` $ sudo stat /proc/1/fd | head -n2 File: /proc/1/fd Size: 0 Blocks: 0 IO Block: 1024 directory ``` With this patch: ``` $ sudo stat /proc/1/fd | head -n2 File: /proc/1/fd Size: 65 Blocks: 0 IO Block: 1024 directory ``` Correctness check: ``` $ sudo ls /proc/1/fd | wc -l 65 ``` I added the docs for /proc/<pid>/fd while I'm at it. [ivan@cloudflare.com: use bitmap_weight() to count the bits] Link: https://lkml.kernel.org/r/20221018045844.37697-1-ivan@cloudflare.com [akpm@linux-foundation.org: include linux/bitmap.h for bitmap_weight()] [ivan@cloudflare.com: return errno from proc_fd_getattr() instead of setting negative size] Link: https://lkml.kernel.org/r/20221024173140.30673-1-ivan@cloudflare.com Link: https://lkml.kernel.org/r/20220922224027.59266-1-ivan@cloudflare.comSigned-off-by:
Ivan Babrou <ivan@cloudflare.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name> Cc: David Hildenbrand <david@redhat.com> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Ivan Babrou <ivan@cloudflare.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by:
-
Jason A. Donenfeld authored
Currently the clamp algorithm does: if (val > hi) val = hi; if (val < lo) val = lo; But since hi > lo by definition, this can be made more efficient with: if (val > hi) val = hi; else if (val < lo) val = lo; So fix up the clamp and clamp_t functions to do this, adding the same argument checking as for min and min_t. For simple cases, code generation on x86_64 and aarch64 stay about the same: before: cmp edi, edx mov eax, esi cmova edi, edx cmp edi, esi cmovnb eax, edi ret after: cmp edi, esi mov eax, edx cmovnb esi, edi cmp edi, edx cmovb eax, esi ret before: cmp w0, w2 csel w8, w0, w2, lo cmp w8, w1 csel w0, w8, w1, hi ret after: cmp w0, w1 csel w8, w0, w1, hi cmp w0, w2 csel w0, w8, w2, lo ret On MIPS64, however, code generation improves, by removing arithmetic in the second branch: before: sltu $3,$6,$4 bne $3,$0,.L2 move $2,$6 move $2,$4 .L2: sltu $3,$2,$5 bnel $3,$0,.L7 move $2,$5 .L7: jr $31 nop after: sltu $3,$4,$6 beq $3,$0,.L13 move $2,$6 sltu $3,$4,$5 bne $3,$0,.L12 move $2,$4 .L13: jr $31 nop .L12: jr $31 move $2,$5 For more complex cases with surrounding code, the effects are a bit more complicated. For example, consider this simplified version of timestamp_truncate() from fs/inode.c on x86_64: struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode) { struct super_block *sb = inode->i_sb; unsigned int gran = sb->s_time_gran; t.tv_sec = clamp(t.tv_sec, sb->s_time_min, sb->s_time_max); if (t.tv_sec == sb->s_time_max || t.tv_sec == sb->s_time_min) t.tv_nsec = 0; return t; } before: mov r8, rdx mov rdx, rsi mov rcx, QWORD PTR [r8] mov rax, QWORD PTR [rcx+8] mov rcx, QWORD PTR [rcx+16] cmp rax, rdi mov r8, rcx cmovge rdi, rax cmp rdi, rcx cmovle r8, rdi cmp rax, r8 je .L4 cmp rdi, rcx jge .L4 mov rax, r8 ret .L4: xor edx, edx mov rax, r8 ret after: mov rax, QWORD PTR [rdx] mov rdx, QWORD PTR [rax+8] mov rax, QWORD PTR [rax+16] cmp rax, rdi jg .L6 mov r8, rax xor edx, edx .L2: mov rax, r8 ret .L6: cmp rdx, rdi mov r8, rdi cmovge r8, rdx cmp rax, r8 je .L4 xor eax, eax cmp rdx, rdi cmovl rax, rsi mov rdx, rax mov rax, r8 ret .L4: xor edx, edx jmp .L2 In this case, we actually gain a branch, unfortunately, because the compiler's replacement axioms no longer as cleanly apply. So all and all, this change is a bit of a mixed bag. Link: https://lkml.kernel.org/r/20220926133435.1333846-2-Jason@zx2c4.comSigned-off-by: -
Jason A. Donenfeld authored
The clamp family of functions only makes sense if hi>=lo. If hi and lo are compile-time constants, then raise a build error. Doing so has already caught buggy code. This also introduces the infrastructure to improve the clamping function in subsequent commits. [akpm@linux-foundation.org: coding-style cleanups] [akpm@linux-foundation.org: s@&&\@&& \@] Link: https://lkml.kernel.org/r/20220926133435.1333846-1-Jason@zx2c4.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by:
-
Chen Lifu authored
This symbol is not used outside of the file, so mark it static. Fixes the following warning: arch/arm/kernel/machine_kexec.c:76:6: warning: symbol 'machine_crash_nonpanic_core' was not declared. Should it be static? Link: https://lkml.kernel.org/r/20220929042936.22012-5-bhe@redhat.comSigned-off-by:
Chen Lifu <chenlifu@huawei.com> Signed-off-by:
-
Li Chen authored
We already have struct range, so just use it. Link: https://lkml.kernel.org/r/20220929042936.22012-4-bhe@redhat.comSigned-off-by:
Li Chen <lchen@ambarella.com> Signed-off-by:
-
ye xingchen authored
Return the value kimage_add_entry() directly instead of storing it in another redundant variable. Link: https://lkml.kernel.org/r/20220929042936.22012-3-bhe@redhat.comSigned-off-by:
Zeal Robot <zealci@zte.com.cn> Acked-by:
-
Jianglei Nie authored
Patch series "Some minor cleanup patches resent". The first three patches trivial clean up patches. And for the patch "kexec: replace crash_mem_range with range", I got a ibm-p9wr ppc64le system to test, it works well. This patch (of 4): elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a predefined value. If parse_crash_elf_headers() gets some error and returns a negetive value, the elfcorehdr_addr should be released with elfcorehdr_free(). Fix it by calling elfcorehdr_free() when parse_crash_elf_headers() fails. Link: https://lkml.kernel.org/r/20220929042936.22012-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20220929042936.22012-2-bhe@redhat.comSigned-off-by:
Jianglei Nie <niejianglei2021@163.com> Signed-off-by:
-
Joseph Qi authored
Use bitmap_zero/bitmap_copy/bitmap_qeual directly for bitmap operations. Link: https://lkml.kernel.org/r/20221007124846.186453-3-joseph.qi@linux.alibaba.comSigned-off-by:
-
Joseph Qi authored
Pass bits directly into fill_node_map helper and use bitmap API directly to simplify code. Link: https://lkml.kernel.org/r/20221007124846.186453-2-joseph.qi@linux.alibaba.comSigned-off-by:
-
Joseph Qi authored
Use bitmap_zero/bitmap_copy/bitmap_equal directly for bitmap operations. Link: https://lkml.kernel.org/r/20221007124846.186453-1-joseph.qi@linux.alibaba.comSigned-off-by:
-
Andy Shevchenko authored
Use str_enabled_disabled() helper instead of open coding the same. Link: https://lkml.kernel.org/r/20221008195914.54199-1-andriy.shevchenko@linux.intel.comSigned-off-by:
-
Uros Bizjak authored
try_cmpxchg implicitly assigns old head->first value to "first" when cmpxchg fails. There is no need to re-read the value in the loop. Link: https://lkml.kernel.org/r/20221017145226.4044-1-ubizjak@gmail.comSigned-off-by:
-
git://githubhttps://github.comPalmer Dabbelt authored
Github deprecated the git:// links about a year ago, so let's move to the https:// URLs instead. Link: https://lkml.kernel.org/r/20221013214638.30953-1-palmer@rivosinc.comReported-by:
Conor Dooley <conor.dooley@microchip.com> Link: https://github.blog/2021-09-01-improving-git-protocol-security-github/Signed-off-by:
Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by:
Cyril Hrubis <chrubis@suse.cz> Reviewed-by:
Petr Vorel <pvorel@suse.cz> Signed-off-by:
-
