Petr Mladek
d697bad588
livepatch: Remove Nop structures when unused ...
Replaced patches are removed from the stack when the transition is
finished. It means that Nop structures will never be needed again
and can be removed. Why should we care?
+ Nop structures give the impression that the function is patched
even though the ftrace handler has no effect.
+ Ftrace handlers do not come for free. They cause slowdown that might
be visible in some workloads. The ftrace-related slowdown might
actually be the reason why the function is no longer patched in
the new cumulative patch. One would expect that cumulative patch
would help solve these problems as well.
+ Cumulative patches are supposed to replace any earlier version of
the patch. The amount of NOPs depends on which version was replaced.
This multiplies the amount of scenarios that might happen.
One might say that NOPs are innocent. But there are even optimized
NOP instructions for different processors, for example, see
arch/x86/kernel/alternative.c. And klp_ftrace_handler() is much
more complicated.
+ It sounds natural to clean up a mess that is no longer needed.
It could only be worse if we do not do it.
This patch allows to unpatch and free the dynamic structures independently
when the transition finishes.
The free part is a bit tricky because kobject free callbacks are called
asynchronously. We could not wait for them easily. Fortunately, we do
not have to. Any further access can be avoided by removing them from
the dynamic lists.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2019-01-11 20:51:24 +01:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
Merge branch 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2018-12-29 10:57:20 -08:00
kvm_config: add CONFIG_VIRTIO_MENU
2018-10-24 20:55:56 -04:00
kdb: use bool for binary state indicators
2018-12-30 08:31:52 +00:00
DMA mapping updates for Linux 4.21
2018-12-28 14:12:21 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
genirq/affinity: Add is_managed to struct irq_affinity_desc
2018-12-19 11:32:08 +01:00
livepatch: Remove Nop structures when unused
2019-01-11 20:51:24 +01:00
kernel/locking/mutex.c: remove caller signal_pending branch predictions
2019-01-04 13:13:48 -08:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
rcutorture: Don't do busted forward-progress testing
2018-12-01 12:45:42 -08:00
Merge branch 'akpm' (patches from Andrew)
2019-01-05 09:16:18 -08:00
y2038: more syscalls and cleanups
2018-12-28 12:45:04 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
audit: remove duplicated include from audit.c
2018-12-14 12:09:30 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: minimize our use of audit_log_format()
2018-11-26 18:40:00 -05:00
audit: use current whenever possible
2018-11-26 18:41:21 -05:00
kbuild: fix kernel/bounds.c 'W=1' warning
2018-10-31 08:54:14 -07:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
x86/speculation: Rework SMT state change
2018-11-28 11:57:07 +01:00
kernel/crash_core.c: print timestamp using time64_t
2018-08-22 10:52:47 -07:00
cred: export get_task_cred().
2018-12-19 13:52:44 -05:00
delayacct: track delays from thrashing cache pages
2018-10-26 16:26:32 -07:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
kernel/fail_function.c: remove meaningless null pointer check before debugfs_remove_recursive
2018-10-31 08:54:12 -07:00
fork: fix some -Wmissing-prototypes warnings
2019-01-04 13:13:47 -08:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
kernel/hung_task.c: break RCU locks based on jiffies
2019-01-04 13:13:45 -08:00
Merge branch 'x86/build' into locking/core, to pick up dependent patches and unify jump-label work
2018-10-16 17:30:11 +02:00
kallsyms: reduce size a little on 64-bit
2018-09-10 22:54:33 +09:00
kconfig: warn no new line at end of file
2018-12-15 17:44:35 +09:00
kernel/kcov.c: mark write_comp_data() as notrace
2019-01-04 13:13:47 -08:00
kexec: add call to LSM hook in original kexec_load syscall
2018-07-16 12:31:57 -07:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
kexec_file: kexec_walk_memblock() only walks a dedicated region at kdump
2018-12-06 14:38:50 +00:00
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 14:45:18 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
y2038: more syscalls and cleanups
2018-12-28 12:45:04 -08:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
Driver core patches for 4.21-rc1
2018-12-28 20:44:29 -08:00
modsign: use all trusted keys to verify module signature
2018-11-07 14:41:41 +01:00
padata: clean an indentation issue, remove extraneous space
2018-11-16 14:11:04 +08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
Fix failure path in alloc_pid()
2018-12-28 12:42:30 -08:00
signal: Use group_send_sig_info to kill all processes in a pid namespace
2018-09-16 16:08:25 +02:00
mm: remove include/linux/bootmem.h
2018-10-31 08:54:16 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
kernel/reboot.c: export pm_power_off_prepare
2018-09-11 16:13:24 +01:00
kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable
2018-12-28 12:11:49 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
seccomp: fix poor type promotion
2018-12-13 16:49:01 -08:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
smp,cpumask: introduce on_each_cpu_cond_mask
2018-10-09 16:51:11 +02:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-10-25 11:43:47 -07:00
stackleak: Mark stackleak_track_stack() as notrace
2018-12-05 19:31:44 -08:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
y2038: socket: Add compat_sys_recvmmsg_time64
2018-12-18 16:13:04 +01:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
torture: Remove unnecessary "ret" variables
2018-12-01 12:45:35 -08:00
tracing: Replace synchronize_sched() and call_rcu_sched()
2018-11-27 09:21:41 -08:00
umh: Add command line to user mode helpers
2018-10-22 19:37:36 -07:00
smp,cpumask: introduce on_each_cpu_cond_mask
2018-10-09 16:51:11 +02:00
userns: use irqsave variant of refcount_dec_and_lock()
2018-08-22 10:52:47 -07:00
userns: also map extents in the reverse map to kernel IDs
2018-11-07 23:51:16 -06:00
sys: don't hold uts_sem while accessing userspace memory
2018-08-11 02:05:53 -05:00
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
workqueue: Replace call_rcu_sched() with call_rcu()
2018-11-27 09:21:44 -08:00
d697bad588