kernel/linux.git/fs/eventfd.c, branch v7.0-rc7

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

eventfd: convert do_eventfd() to FD_PREPARE()

2025-11-28T11:42:31+00:00

Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-3-b6efa1706cfd@kernel.org Signed-off-by: Christian Brauner

make use of anon_inode_getfile_fmode()

2025-02-21T09:25:31+00:00

["fallen through the cracks" misc stuff] A bunch of anon_inode_getfile() callers follow it with adjusting ->f_mode; we have a helper doing that now, so let's make use of it. Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20250118014434.GT1977892@ZenIV Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

fdget(), trivial conversions

2024-11-03T06:28:06+00:00

fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner Signed-off-by: Al Viro

introduce fd_file(), convert all accessors to it.

2024-08-13T02:00:43+00:00

For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner Signed-off-by: Al Viro

eventfd: strictly check the count parameter of eventfd_write to avoid inputting illegal strings

2024-02-08T09:12:26+00:00

Since eventfd's document has clearly stated: A write(2) call adds the 8-byte integer value supplied in its buffer to the counter. However, in the current implementation, the following code snippet did not cause an error: char str[16] = "hello world"; uint64_t value; ssize_t size; int fd; fd = eventfd(0, 0); size = write(fd, &str, strlen(str)); printf("eventfd: test writing a string, size=%ld\n", size); size = read(fd, &value, sizeof(value)); printf("eventfd: test reading as uint64, size=%ld, valus=0x%lX\n", size, value); close(fd); And its output is: eventfd: test writing a string, size=8 eventfd: test reading as uint64, size=8, valus=0x6F77206F6C6C6568 By checking whether count is equal to sizeof(ucnt), such errors could be detected. It also follows the requirements of the manual. Signed-off-by: Wen Yang Link: https://lore.kernel.org/r/tencent_10AAA44731FFFA493F9F5501521F07DD4D0A@qq.com Cc: Alexander Viro Cc: Jens Axboe Cc: Christian Brauner Cc: Jan Kara Cc: David Woodhouse Cc: Matthew Wilcox Cc: Eric Biggers Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Christian Brauner

eventfd: move 'eventfd-count' printing out of spinlock

2024-01-23T16:56:29+00:00

When printing eventfd->count, interrupts will be disabled and a spinlock will be obtained, competing with eventfd_write(). By moving the "eventfd-count" print out of the spinlock and merging multiple seq_printf() into one, it could improve a bit, just like timerfd_show(). Signed-off-by: Wen Yang Link: https://lore.kernel.org/r/tencent_B0B3D2BD9861FD009E03AB18A81783322709@qq.com Cc: Alexander Viro Cc: Jens Axboe Cc: Christian Brauner Cc: Christoph Hellwig Cc: Dylan Yudaken Cc: David Woodhouse Cc: Matthew Wilcox Cc: Eric Biggers Cc: Cc: Signed-off-by: Christian Brauner

eventfd: add a BUILD_BUG_ON() to ensure consistency between EFD_SEMAPHORE and the uapi

2024-01-22T14:33:36+00:00

introduce a BUILD_BUG_ON to check that the EFD_SEMAPHORE is equal to its definition in the uapi file, just like EFD_CLOEXEC and EFD_NONBLOCK. Signed-off-by: Wen Yang Link: https://lore.kernel.org/r/tencent_0BAA2DEAF9208D49987457E6583F9BE79507@qq.com Cc: Alexander Viro Cc: Christian Brauner Cc: Jens Axboe Cc: Jan Kara Cc: Cc: Signed-off-by: Christian Brauner

eventfd: Remove usage of the deprecated ida_simple_xx() API

2023-12-12T13:24:55+00:00

ida_alloc() and ida_free() should be preferred to the deprecated ida_simple_get() and ida_simple_remove(). This is less verbose. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/575dcecd51097dd30c5515f9f0ed92076b4ef403.1702229520.git.christophe.jaillet@wanadoo.fr Reviewed-by: Jan Kara Signed-off-by: Christian Brauner