Eric W. Biederman 66ed594409 bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu ... When discussing[1] exec and posix file locks it was realized that none of the callers of get_files_struct fundamentally needed to call get_files_struct, and that by switching them to helper functions instead it will both simplify their code and remove unnecessary increments of files_struct.count. Those unnecessary increments can result in exec unnecessarily unsharing files_struct which breaking posix locks, and it can result in fget_light having to fallback to fget reducing system performance. Using task_lookup_next_fd_rcu simplifies task_file_seq_get_next, by moving the checking for the maximum file descritor into the generic code, and by remvoing the need for capturing and releasing a reference on files_struct. As the reference count of files_struct no longer needs to be maintained bpf_iter_seq_task_file_info can have it's files member removed and task_file_seq_get_next no longer needs it's fstruct argument. The curr_fd local variable does need to become unsigned to be used with fnext_task. As curr_fd is assigned from and assigned a u32 making curr_fd an unsigned int won't cause problems and might prevent them. [1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com Suggested-by: Oleg Nesterov <oleg@redhat.com> v1: https://lkml.kernel.org/r/20200817220425.9389-11-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-16-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>		2020-12-10 12:42:58 -06:00
..
bpf	bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu	2020-12-10 12:42:58 -06:00
cgroup	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
configs
debug	kdb: Fix pager search for multi-line strings	2020-10-01 14:44:08 +01:00
dma	dma-mapping: move more functions to dma-map-ops.h	2020-10-20 10:41:07 +02:00
entry	arch-cleanup-2020-10-22	2020-10-23 10:06:38 -07:00
events	task_work: cleanup notification modes	2020-10-17 15:05:30 -06:00
gcov
irq	task_work: cleanup notification modes	2020-10-17 15:05:30 -06:00
kcsan	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
livepatch	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
locking	Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2020-10-18 14:34:50 -07:00
power	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
printk	Urgent printk fix for 5.10	2020-10-16 12:52:37 -07:00
rcu	Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2020-10-18 14:34:50 -07:00
sched	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
time	random32: add noise from network and scheduling activity	2020-10-24 20:21:57 +02:00
trace	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
.gitignore
acct.c	kernel: acct.c: fix some kernel-doc nits	2020-10-16 11:11:19 -07:00
async.c
audit.c	audit: Remove redundant null check	2020-08-26 09:10:39 -04:00
audit.h
audit_fsnotify.c
audit_tree.c
audit_watch.c
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
compat.c
configs.c
context_tracking.c	context_tracking: Ensure that the critical path cannot be instrumented	2020-06-11 15:14:36 +02:00
cpu.c
cpu_pm.c	notifier: Fix broken error handling pattern	2020-09-01 09:58:03 +02:00
crash_core.c	kdump: append kernel build-id string to VMCOREINFO	2020-08-12 10:58:01 -07:00
crash_dump.c
cred.c	exec: Teach prepare_exec_creds how exec treats uids & gids	2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c	kernel/elfcore.c: include proper prototypes	2019-09-25 17:51:39 -07:00
exec_domain.c
exit.c	pid: move pidfd_get_pid() to pid.c	2020-10-18 09:27:10 -07:00
extable.c	kernel/extable.c: use address-of operator on section symbols	2020-04-07 10:43:42 -07:00
fail_function.c
fork.c	exec: Simplify unshare_files	2020-12-10 12:39:32 -06:00
freezer.c
futex.c	futex: Adjust absolute futex timeouts with per time namespace offset	2020-10-20 17:02:57 +02:00
gen_kheaders.sh
groups.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
hung_task.c
iomem.c
irq_work.c
jump_label.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
kallsyms.c	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
kcmp.c	kcmp: In get_file_raw_ptr use task_lookup_fd_rcu	2020-12-10 12:42:49 -06:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec.c	LSM: Introduce kernel_post_load_data() hook	2020-10-05 13:37:03 +02:00
kexec_core.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
kexec_elf.c
kexec_file.c	kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED	2020-10-16 11:11:18 -07:00
kexec_internal.h	kexec: add machine_kexec_post_load()	2020-01-08 16:32:55 +00:00
kheaders.c
kmod.c
kprobes.c	Updates for tracing and bootconfig:	2020-10-15 15:51:28 -07:00
ksysfs.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 170	2019-05-30 11:26:39 -07:00
kthread.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
latencytop.c
Makefile	Kbuild updates for v5.10	2020-10-22 13:13:57 -07:00
module-internal.h
module.c	Modules updates for v5.10	2020-10-22 13:08:57 -07:00
module_signature.c	MODSIGN: Export module signature definitions	2019-08-05 18:39:56 -04:00
module_signing.c
notifier.c	notifier: Fix broken error handling pattern	2020-09-01 09:58:03 +02:00
nsproxy.c
padata.c
panic.c	panic: dump registers on panic_on_warn	2020-10-16 11:11:22 -07:00
params.c
pid.c	pid: move pidfd_get_pid() to pid.c	2020-10-18 09:27:10 -07:00
pid_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
profile.c
ptrace.c
range.c	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
reboot.c
regset.c
relay.c	kernel/relay.c: drop unneeded initialization	2020-10-16 11:11:22 -07:00
resource.c	kernel/resource: make iomem_resource implicit in release_mem_region_adjustable()	2020-10-16 11:11:18 -07:00
rseq.c	rseq: Reject unknown flags on rseq unregister	2019-12-25 10:41:20 +01:00
scftorture.c	scftorture: Add cond_resched() to test loop	2020-08-24 18:38:38 -07:00
scs.c
seccomp.c	seccomp: Make duplicate listener detection non-racy	2020-10-08 13:17:47 -07:00
signal.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
smp.c	Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2020-10-18 14:34:50 -07:00
smpboot.c
smpboot.h
softirq.c	softirq: Add debug check to __raise_softirq_irqoff()	2020-09-16 15:18:56 +02:00
stackleak.c	stackleak: let stack_erasing_sysctl take a kernel pointer buffer	2020-09-19 13:13:39 -07:00
stacktrace.c	stacktrace: Remove reliable argument from arch_stack_walk() callback	2020-09-18 14:24:16 +01:00
static_call.c	static_call: Fix return type of static_call_init	2020-10-02 21:18:25 +02:00
stop_machine.c
sys.c	kernel/sys.c: fix prototype of prctl_get_tid_address()	2020-10-25 11:44:16 -07:00
sys_ni.c	mm/madvise: introduce process_madvise() syscall: an external memory hinting API	2020-10-18 09:27:10 -07:00
sysctl-test.c
sysctl.c	mm: allow a controlled amount of unfairness in the page lock	2020-09-17 10:26:41 -07:00
task_work.c	task_work: cleanup notification modes	2020-10-17 15:05:30 -06:00
taskstats.c	taskstats: move specifying netlink policy back to ops	2020-10-02 19:11:12 -07:00
test_kprobes.c
torture.c	torture: Dump ftrace at shutdown only if requested	2020-06-29 12:01:45 -07:00
tracepoint.c	tracepoint: Fix out of sync data passing by static caller	2020-10-02 21:18:25 +02:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c	usermodehelper: reset umask to default before executing user process	2020-10-06 10:31:52 -07:00
up.c
user-return-notifier.c
user.c
user_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
usermode_driver.c
utsname.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
utsname_sysctl.c
watch_queue.c
watchdog.c
watchdog_hld.c	kernel/watchdog_hld.c: hard lockup message should end with a newline	2019-04-19 09:46:05 -07:00
workqueue.c	workqueue: fix a kernel-doc warning	2020-10-16 07:28:20 +02:00
workqueue_internal.h