b454ec2922
778 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Oleg Nesterov
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b454ec2922 |
kernel/signal.c: simplify force_sig_info_to_task(), kill recalc_sigpending_and_wake()
The purpose of recalc_sigpending_and_wake() is not clear, it looks "obviously unneeded" because we are going to send the signal which can't be blocked or ignored. Add the comment to explain why we can't rely on send_signal_locked() and make this logic more simple/explicit. recalc_sigpending_and_wake() has no other users, it can die. In fact I think we don't even need signal_wake_up(), the target task must be either current or a TASK_TRACED child, otherwise the usage of siglock is not safe. But this needs another change. Link: https://lkml.kernel.org/r/20231120151649.GA15995@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Oleg Nesterov
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61a7a5e25f |
introduce for_other_threads(p, t)
Cosmetic, but imho it makes the usage look more clear and simple, the new helper doesn't require to initialize "t". After this change while_each_thread() has only 3 users, and it is only used in the do/while loops. Link: https://lkml.kernel.org/r/20231030155710.GA9095@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Linus Torvalds
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8f6f76a6a2 |
As usual, lots of singleton and doubleton patches all over the tree and
there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- "kdump: use generic functions to simplify crashkernel reservation in
arch", from Baoquan He. This is mainly cleanups and consolidation of
the "crashkernel=" kernel parameter handling.
- After much discussion, David Laight's "minmax: Relax type checks in
min() and max()" is here. Hopefully reduces some typecasting and the
use of min_t() and max_t().
- A group of patches from Oleg Nesterov which clean up and slightly fix
our handling of reads from /proc/PID/task/... and which remove
task_struct.therad_group.
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Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"As usual, lots of singleton and doubleton patches all over the tree
and there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- 'kdump: use generic functions to simplify crashkernel reservation
in arch', from Baoquan He. This is mainly cleanups and
consolidation of the 'crashkernel=' kernel parameter handling
- After much discussion, David Laight's 'minmax: Relax type checks in
min() and max()' is here. Hopefully reduces some typecasting and
the use of min_t() and max_t()
- A group of patches from Oleg Nesterov which clean up and slightly
fix our handling of reads from /proc/PID/task/... and which remove
task_struct.thread_group"
* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
scripts/gdb/vmalloc: disable on no-MMU
scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
.mailmap: add address mapping for Tomeu Vizoso
mailmap: update email address for Claudiu Beznea
tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
.mailmap: map Benjamin Poirier's address
scripts/gdb: add lx_current support for riscv
ocfs2: fix a spelling typo in comment
proc: test ProtectionKey in proc-empty-vm test
proc: fix proc-empty-vm test with vsyscall
fs/proc/base.c: remove unneeded semicolon
do_io_accounting: use sig->stats_lock
do_io_accounting: use __for_each_thread()
ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
ocfs2: fix a typo in a comment
scripts/show_delta: add __main__ judgement before main code
treewide: mark stuff as __ro_after_init
fs: ocfs2: check status values
proc: test /proc/${pid}/statm
compiler.h: move __is_constexpr() to compiler.h
...
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Linus Torvalds
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1e0c505e13 |
asm-generic updates for v6.7
The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEiK/NIGsWEZVxh/FrYKtH/8kJUicFAmVC40IACgkQYKtH/8kJ Uidhmw/9EX+aWSXGoObJ3fngaNSMw+PmrEuP8qEKBHxfKHcCdX3hc451Oh4GlhaQ tru91pPwgNvN2/rfoKusxT+V4PemGIzfNni/04rp+P0kvmdw5otQ2yNhsQNsfVmq XGWvkxF4P2GO6bkjjfR/1dDq7GtlyXtwwPDKeLbYb6TnJOZjtx+EAN27kkfSn1Ms R4Sa3zJ+DfHUmHL5S9g+7UD/CZ5GfKNmIskI4Mz5GsfoUz/0iiU+Bge/9sdcdSJQ kmbLy5YnVzfooLZ3TQmBFsO3iAMWb0s/mDdtyhqhTVmTUshLolkPYyKnPFvdupyv shXcpEST2XJNeaDRnL2K4zSCdxdbnCZHDpjfl9wfioBg7I8NfhXKpf1jYZHH1de4 LXq8ndEFEOVQw/zSpYWfQq1sux8Jiqr+UK/ukbVeFWiGGIUs91gEWtPAf8T0AZo9 ujkJvaWGl98O1g5wmBu0/dAR6QcFJMDfVwbmlIFpU8O+MEaz6X8mM+O5/T0IyTcD eMbAUjj4uYcU7ihKzHEv/0SS9Of38kzff67CLN5k8wOP/9NlaGZ78o1bVle9b52A BdhrsAefFiWHp1jT6Y9Rg4HOO/TguQ9e6EWSKOYFulsiLH9LEFaB9RwZLeLytV0W vlAgY9rUW77g1OJcb7DoNv33nRFuxsKqsnz3DEIXtgozo9CzbYI= =H1vH -----END PGP SIGNATURE----- Merge tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull ia64 removal and asm-generic updates from Arnd Bergmann: - The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. - The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. * tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: hexagon: Remove unusable symbols from the ptrace.h uapi asm-generic: Fix spelling of architecture arch: Reserve map_shadow_stack() syscall number for all architectures syscalls: Cleanup references to sys_lookup_dcookie() Documentation: Drop or replace remaining mentions of IA64 lib/raid6: Drop IA64 support Documentation: Drop IA64 from feature descriptions kernel: Drop IA64 support from sig_fault handlers arch: Remove Itanium (IA-64) architecture |
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Li kunyu
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a287116af1 |
kernel/signal: remove unnecessary NULL values from ucounts
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> |
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Oleg Nesterov
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e5ecf29c50 |
signal: complete_signal: use __for_each_thread()
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> |
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Oleg Nesterov
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3983520491 |
__kill_pgrp_info: simplify the calculation of return value
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> |
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Sebastian Andrzej Siewior
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1aabbc5324 |
signal: Don't disable preemption in ptrace_stop() on PREEMPT_RT
On PREEMPT_RT keeping preemption disabled during the invocation of cgroup_enter_frozen() is a problem because the function acquires css_set_lock which is a sleeping lock on PREEMPT_RT and must not be acquired with disabled preemption. The preempt-disabled section is only for performance optimisation reasons and can be avoided. Extend the comment and don't disable preemption before scheduling on PREEMPT_RT. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20230803100932.325870-3-bigeasy@linutronix.de |
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Sebastian Andrzej Siewior
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a20d6f63db |
signal: Add a proper comment about preempt_disable() in ptrace_stop()
Commit
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Ard Biesheuvel
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f5e836884d |
kernel: Drop IA64 support from sig_fault handlers
Signed-off-by: Ard Biesheuvel <ardb@kernel.org> |
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Vincent Whitchurch
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b0b88e02f0 |
signal: print comm and exe name on fatal signals
Make the print-fatal-signals message more useful by printing the comm
and the exe name for the process which received the fatal signal:
Before:
potentially unexpected fatal signal 4
potentially unexpected fatal signal 11
After:
buggy-program: pool: potentially unexpected fatal signal 4
some-daemon: gdbus: potentially unexpected fatal signal 11
comm used to be present but was removed in commit
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Linus Torvalds
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5f0bc0b042 |
mm: suppress mm fault logging if fatal signal already pending
Commit |
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Linus Torvalds
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6a8cbd9253 |
v6.5-rc1-sysctl-next
The changes queued up for v6.5-rc1 for sysctl are in line with prior efforts to stop usage of deprecated routines which incur recursion and also make it hard to remove the empty array element in each sysctl array declaration. The most difficult user to modify was parport which required a bit of re-thinking of how to declare shared sysctls there, Joel Granados has stepped up to the plate to do most of this work and eventual removal of register_sysctl_table(). That work ended up saving us about 1465 bytes according to bloat-o-meter. Since we gained a few bloat-o-meter karma points I moved two rather small sysctl arrays from kernel/sysctl.c leaving us only two more sysctl arrays to move left. Most changes have been tested on linux-next for about a month. The last straggler patches are a minor parport fix, changes to the sysctl kernel selftest so to verify correctness and prevent regressions for the future change he made to provide an alternative solution for the special sysctl mount point target which was using the now deprecated sysctl child element. This is all prep work to now finally be able to remove the empty array element in all sysctl declarations / registrations which is expected to save us a bit of bytes all over the kernel. That work will be tested early after v6.5-rc1 is out. -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEENnNq2KuOejlQLZofziMdCjCSiKcFAmSceh0SHG1jZ3JvZkBr ZXJuZWwub3JnAAoJEM4jHQowkoinBFQQAK9WdpcU8ODoDzoSls4jsCQpZUCfZ+ED pbCgQqUqu9VPs6bnJ+aXVa6Fh3uCr6+TIfNFM55qI/Sbo2issZ7bm0nvKmGgc6/m giqDP7btvHqiAsEootci8DVdbBXKkdH4dx3pSwleyN8pdinewH0hrKImaPpahyo6 1mB1du0iI89yjsZmheHVVSyfXXYAnP0PqRVy5Y+qxY7yYlIegQ5uAZmwRE62lfTf TuiV7OFuDZ2DBYOmqIhfGKGRnfOL5ZVF3iHCrfUpX3p+fEFzDmwvm3vr73PTSrFw /aRRLa/hOWr5ilw1bvnMcazgQzFEOlQb3DMhBKH7gLl3XHVrM+TaaqYHjUia1+6Y e2axz/duA2q9uLMW81daRApvHMCgy0exkpC7prfOxF5bgTe4TjA7ZWvGpqG1kPKT PPSxw80XvG5hLZm4tB0ZWJ5rOfFpiUGGneSeRQwyuClBt73SIO+F03jyGpt83slU jFE50ac14Zwh1oxpCQtYoR1+bXWdq1QwM5vQBNEuaoTSnJfVjrXqBz/BnqJChtjr m1vA27+4/dfki2P3gVWF1lGx43ir3uJvqk+BjWXm2CDDJqpRi3N0qcUwZwLuqAAz /LEgFqK61bpHi/C8c2NWAxIoeWRU4NUOaoiKmZwyt0sKAWU1Yzg70xssYeg7VYqZ 3pvFNVBqkV+F =sXUU -----END PGP SIGNATURE----- Merge tag 'v6.5-rc1-sysctl-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "The changes for sysctl are in line with prior efforts to stop usage of deprecated routines which incur recursion and also make it hard to remove the empty array element in each sysctl array declaration. The most difficult user to modify was parport which required a bit of re-thinking of how to declare shared sysctls there, Joel Granados has stepped up to the plate to do most of this work and eventual removal of register_sysctl_table(). That work ended up saving us about 1465 bytes according to bloat-o-meter. Since we gained a few bloat-o-meter karma points I moved two rather small sysctl arrays from kernel/sysctl.c leaving us only two more sysctl arrays to move left. Most changes have been tested on linux-next for about a month. The last straggler patches are a minor parport fix, changes to the sysctl kernel selftest so to verify correctness and prevent regressions for the future change he made to provide an alternative solution for the special sysctl mount point target which was using the now deprecated sysctl child element. This is all prep work to now finally be able to remove the empty array element in all sysctl declarations / registrations which is expected to save us a bit of bytes all over the kernel. That work will be tested early after v6.5-rc1 is out" * tag 'v6.5-rc1-sysctl-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: replace child with an enumeration sysctl: Remove debugging dump_stack test_sysclt: Test for registering a mount point test_sysctl: Add an option to prevent test skip test_sysctl: Add an unregister sysctl test test_sysctl: Group node sysctl test under one func test_sysctl: Fix test metadata getters parport: plug a sysctl register leak sysctl: move security keys sysctl registration to its own file sysctl: move umh sysctl registration to its own file signal: move show_unhandled_signals sysctl to its own file sysctl: remove empty dev table sysctl: Remove register_sysctl_table sysctl: Refactor base paths registrations sysctl: stop exporting register_sysctl_table parport: Removed sysctl related defines parport: Remove register_sysctl_table from parport_default_proc_register parport: Remove register_sysctl_table from parport_device_proc_register parport: Remove register_sysctl_table from parport_proc_register parport: Move magic number "15" to a define |
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Mike Christie
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f9010dbdce |
fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
When switching from kthreads to vhost_tasks two bugs were added:
1. The vhost worker tasks's now show up as processes so scripts doing
ps or ps a would not incorrectly detect the vhost task as another
process. 2. kthreads disabled freeze by setting PF_NOFREEZE, but
vhost tasks's didn't disable or add support for them.
To fix both bugs, this switches the vhost task to be thread in the
process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call
get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that
SIGKILL/STOP support is required because CLONE_THREAD requires
CLONE_SIGHAND which requires those 2 signals to be supported.
This is a modified version of the patch written by Mike Christie
<michael.christie@oracle.com> which was a modified version of patch
originally written by Linus.
Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER.
Including ignoring signals, setting up the register state, and having
get_signal return instead of calling do_group_exit.
Tidied up the vhost_task abstraction so that the definition of
vhost_task only needs to be visible inside of vhost_task.c. Making
it easier to review the code and tell what needs to be done where.
As part of this the main loop has been moved from vhost_worker into
vhost_task_fn. vhost_worker now returns true if work was done.
The main loop has been updated to call get_signal which handles
SIGSTOP, freezing, and collects the message that tells the thread to
exit as part of process exit. This collection clears
__fatal_signal_pending. This collection is not guaranteed to
clear signal_pending() so clear that explicitly so the schedule()
sleeps.
For now the vhost thread continues to exist and run work until the
last file descriptor is closed and the release function is called as
part of freeing struct file. To avoid hangs in the coredump
rendezvous and when killing threads in a multi-threaded exec. The
coredump code and de_thread have been modified to ignore vhost threads.
Remvoing the special case for exec appears to require teaching
vhost_dev_flush how to directly complete transactions in case
the vhost thread is no longer running.
Removing the special case for coredump rendezvous requires either the
above fix needed for exec or moving the coredump rendezvous into
get_signal.
Fixes:
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Luis Chamberlain
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01e6aac78b |
signal: move show_unhandled_signals sysctl to its own file
The show_unhandled_signals sysctl is the only sysctl for debug left on kernel/sysctl.c. We've been moving the syctls out from kernel/sysctl.c so to help avoid merge conflicts as the shared array gets out of hand. This change incurs simplifies sysctl registration by localizing it where it should go for a penalty in size of increasing the kernel by 23 bytes, we accept this given recent cleanups have actually already saved us 1465 bytes in the prior commits. ./scripts/bloat-o-meter vmlinux.3-remove-dev-table vmlinux.4-remove-debug-table add/remove: 3/1 grow/shrink: 0/1 up/down: 177/-154 (23) Function old new delta signal_debug_table - 128 +128 init_signal_sysctls - 33 +33 __pfx_init_signal_sysctls - 16 +16 sysctl_init_bases 85 59 -26 debug_table 128 - -128 Total: Before=21256967, After=21256990, chg +0.00% Reviewed-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
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Dmitry Vyukov
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bcb7ee7902 |
posix-timers: Prefer delivery of signals to the current thread
POSIX timers using the CLOCK_PROCESS_CPUTIME_ID clock prefer the main thread of a thread group for signal delivery. However, this has a significant downside: it requires waking up a potentially idle thread. Instead, prefer to deliver signals to the current thread (in the same thread group) if SIGEV_THREAD_ID is not set by the user. This does not change guaranteed semantics, since POSIX process CPU time timers have never guaranteed that signal delivery is to a specific thread (without SIGEV_THREAD_ID set). The effect is that queueing the signal no longer wakes up potentially idle threads, and the kernel is no longer biased towards delivering the timer signal to any particular thread (which better distributes the timer signals esp. when multiple timers fire concurrently). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230316123028.2890338-1-elver@google.com |
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Mathieu Desnoyers
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af7f588d8f |
sched: Introduce per-memory-map concurrency ID
This feature allows the scheduler to expose a per-memory map concurrency ID to user-space. This concurrency ID is within the possible cpus range, and is temporarily (and uniquely) assigned while threads are actively running within a memory map. If a memory map has fewer threads than cores, or is limited to run on few cores concurrently through sched affinity or cgroup cpusets, the concurrency IDs will be values close to 0, thus allowing efficient use of user-space memory for per-cpu data structures. This feature is meant to be exposed by a new rseq thread area field. The primary purpose of this feature is to do the heavy-lifting needed by memory allocators to allow them to use per-cpu data structures efficiently in the following situations: - Single-threaded applications, - Multi-threaded applications on large systems (many cores) with limited cpu affinity mask, - Multi-threaded applications on large systems (many cores) with restricted cgroup cpuset per container. One of the key concern from scheduler maintainers is the overhead associated with additional spin locks or atomic operations in the scheduler fast-path. This is why the following optimization is implemented. On context switch between threads belonging to the same memory map, transfer the mm_cid from prev to next without any atomic ops. This takes care of use-cases involving frequent context switch between threads belonging to the same memory map. Additional optimizations can be done if the spin locks added when context switching between threads belonging to different memory maps end up being a performance bottleneck. Those are left out of this patch though. A performance impact would have to be clearly demonstrated to justify the added complexity. The credit goes to Paul Turner (Google) for the original virtual cpu id idea. This feature is implemented based on the discussions with Paul Turner and Peter Oskolkov (Google), but I took the liberty to implement scheduler fast-path optimizations and my own NUMA-awareness scheme. The rumor has it that Google have been running a rseq vcpu_id extension internally in production for a year. The tcmalloc source code indeed has comments hinting at a vcpu_id prototype extension to the rseq system call [1]. The following benchmarks do not show any significant overhead added to the scheduler context switch by this feature: * perf bench sched messaging (process) Baseline: 86.5±0.3 ms With mm_cid: 86.7±2.6 ms * perf bench sched messaging (threaded) Baseline: 84.3±3.0 ms With mm_cid: 84.7±2.6 ms * hackbench (process) Baseline: 82.9±2.7 ms With mm_cid: 82.9±2.9 ms * hackbench (threaded) Baseline: 85.2±2.6 ms With mm_cid: 84.4±2.9 ms [1] https://github.com/google/tcmalloc/blob/master/tcmalloc/internal/linux_syscall_support.h#L26 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20221122203932.231377-8-mathieu.desnoyers@efficios.com |
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Linus Torvalds
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48ea09cdda |
hardening updates for v6.2-rc1
- Convert flexible array members, fix -Wstringop-overflow warnings,
and fix KCFI function type mismatches that went ignored by
maintainers (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook).
- Remove the remaining side-effect users of ksize() by converting
dma-buf, btrfs, and coredump to using kmalloc_size_roundup(),
add more __alloc_size attributes, and introduce full testing
of all allocator functions. Finally remove the ksize() side-effect
so that each allocation-aware checker can finally behave without
exceptions.
- Introduce oops_limit (default 10,000) and warn_limit (default off)
to provide greater granularity of control for panic_on_oops and
panic_on_warn (Jann Horn, Kees Cook).
- Introduce overflows_type() and castable_to_type() helpers for
cleaner overflow checking.
- Improve code generation for strscpy() and update str*() kern-doc.
- Convert strscpy and sigphash tests to KUnit, and expand memcpy
tests.
- Always use a non-NULL argument for prepare_kernel_cred().
- Disable structleak plugin in FORTIFY KUnit test (Anders Roxell).
- Adjust orphan linker section checking to respect CONFIG_WERROR
(Xin Li).
- Make sure siginfo is cleared for forced SIGKILL (haifeng.xu).
- Fix um vs FORTIFY warnings for always-NULL arguments.
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Merge tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull kernel hardening updates from Kees Cook:
- Convert flexible array members, fix -Wstringop-overflow warnings, and
fix KCFI function type mismatches that went ignored by maintainers
(Gustavo A. R. Silva, Nathan Chancellor, Kees Cook)
- Remove the remaining side-effect users of ksize() by converting
dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add
more __alloc_size attributes, and introduce full testing of all
allocator functions. Finally remove the ksize() side-effect so that
each allocation-aware checker can finally behave without exceptions
- Introduce oops_limit (default 10,000) and warn_limit (default off) to
provide greater granularity of control for panic_on_oops and
panic_on_warn (Jann Horn, Kees Cook)
- Introduce overflows_type() and castable_to_type() helpers for cleaner
overflow checking
- Improve code generation for strscpy() and update str*() kern-doc
- Convert strscpy and sigphash tests to KUnit, and expand memcpy tests
- Always use a non-NULL argument for prepare_kernel_cred()
- Disable structleak plugin in FORTIFY KUnit test (Anders Roxell)
- Adjust orphan linker section checking to respect CONFIG_WERROR (Xin
Li)
- Make sure siginfo is cleared for forced SIGKILL (haifeng.xu)
- Fix um vs FORTIFY warnings for always-NULL arguments
* tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits)
ksmbd: replace one-element arrays with flexible-array members
hpet: Replace one-element array with flexible-array member
um: virt-pci: Avoid GCC non-NULL warning
signal: Initialize the info in ksignal
lib: fortify_kunit: build without structleak plugin
panic: Expose "warn_count" to sysfs
panic: Introduce warn_limit
panic: Consolidate open-coded panic_on_warn checks
exit: Allow oops_limit to be disabled
exit: Expose "oops_count" to sysfs
exit: Put an upper limit on how often we can oops
panic: Separate sysctl logic from CONFIG_SMP
mm/pgtable: Fix multiple -Wstringop-overflow warnings
mm: Make ksize() a reporting-only function
kunit/fortify: Validate __alloc_size attribute results
drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()
drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()
driver core: Add __alloc_size hint to devm allocators
overflow: Introduce overflows_type() and castable_to_type()
coredump: Proactively round up to kmalloc bucket size
...
|
||
haifeng.xu
|
3a017d6355 |
signal: Initialize the info in ksignal
When handing the SIGNAL_GROUP_EXIT flag, the info in ksignal isn't cleared. However, the info acquired by dequeue_synchronous_signal/dequeue_signal is initialized and can be safely used. Fortunately, the fatal signal process just uses the si_signo and doesn't use any other member. Even so, the initialization before use is more safer. Signed-off-by: haifeng.xu <haifeng.xu@shopee.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221128065606.19570-1-haifeng.xu@shopee.com |
||
Al Viro
|
6a542d1d5f |
kill signal_pt_regs()
Once upon at it was used on hot paths, but that had not been true since 2013. IOW, there's no point for arch-optimized equivalent of task_pt_regs(current) - remaining two users are not worth bothering with. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Linus Torvalds
|
30c999937f |
Scheduler changes for v6.1:
- Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
- Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
- Freezer:
- Rewrite the core freezer to behave better wrt thawing and be simpler
in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
all the fallout.
- Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
- Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
Freezer:
- Rewrite the core freezer to behave better wrt thawing and be
simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
fixing/adjusting all the fallout.
Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() &
replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications"
* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
sched: Fix more TASK_state comparisons
sched: Fix TASK_state comparisons
sched/fair: Move call to list_last_entry() in detach_tasks
sched/fair: Cleanup loop_max and loop_break
sched/fair: Make sure to try to detach at least one movable task
sched: Show PF_flag holes
freezer,sched: Rewrite core freezer logic
sched: Widen TAKS_state literals
sched/wait: Add wait_event_state()
sched/completion: Add wait_for_completion_state()
sched: Add TASK_ANY for wait_task_inactive()
sched: Change wait_task_inactive()s match_state
freezer,umh: Clean up freezer/initrd interaction
freezer: Have {,un}lock_system_sleep() save/restore flags
sched: Rename task_running() to task_on_cpu()
sched/fair: Cleanup for SIS_PROP
sched/fair: Default to false in test_idle_cores()
sched/fair: Remove useless check in select_idle_core()
sched/fair: Avoid double search on same cpu
sched/fair: Remove redundant check in select_idle_smt()
...
|
||
Peter Zijlstra
|
f5d39b0208 |
freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.
By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.
As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).
Specifically; the current scheme works a little like:
freezer_do_not_count();
schedule();
freezer_count();
And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.
However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.
That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.
This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.
As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:
TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN
The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).
The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.
With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
|
||
Eric W. Biederman
|
9a95f78eab |
signal: Drop signals received after a fatal signal has been processed
In
|
||
|
Linus Torvalds
|
a382f8fee4 |
signal handling: don't use BUG_ON() for debugging
These are indeed "should not happen" situations, but it turns out recent changes made the 'task_is_stopped_or_trace()' case trigger (fix for that exists, is pending more testing), and the BUG_ON() makes it unnecessarily hard to actually debug for no good reason. It's been that way for a long time, but let's make it clear: BUG_ON() is not good for debugging, and should never be used in situations where you could just say "this shouldn't happen, but we can continue". Use WARN_ON_ONCE() instead to make sure it gets logged, and then just continue running. Instead of making the system basically unusuable because you crashed the machine while potentially holding some very core locks (eg this function is commonly called while holding 'tasklist_lock' for writing). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
67850b7bdc |
While looking at the ptrace problems with PREEMPT_RT and the problems
of Peter Zijlstra was encountering with ptrace in his freezer rewrite I identified some cleanups to ptrace_stop that make sense on their own and move make resolving the other problems much simpler. The biggest issue is the habbit of the ptrace code to change task->__state from the tracer to suppress TASK_WAKEKILL from waking up the tracee. No other code in the kernel does that and it is straight forward to update signal_wake_up and friends to make that unnecessary. Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying on the fact that all stopped states except the special stop states can tolerate spurious wake up and recover their state. The state of stopped and traced tasked is changed to be stored in task->jobctl as well as in task->__state. This makes it possible for the freezer to recover tasks in these special states, as well as serving as a general cleanup. With a little more work in that direction I believe TASK_STOPPED can learn to tolerate spurious wake ups and become an ordinary stop state. The TASK_TRACED state has to remain a special state as the registers for a process are only reliably available when the process is stopped in the scheduler. Fundamentally ptrace needs acess to the saved register values of a task. There are bunch of semi-random ptrace related cleanups that were found while looking at these issues. One cleanup that deserves to be called out is from commit |
||
|
Peter Zijlstra
|
31cae1eaae |
sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
Currently ptrace_stop() / do_signal_stop() rely on the special states
TASK_TRACED and TASK_STOPPED resp. to keep unique state. That is, this
state exists only in task->__state and nowhere else.
There's two spots of bother with this:
- PREEMPT_RT has task->saved_state which complicates matters,
meaning task_is_{traced,stopped}() needs to check an additional
variable.
- An alternative freezer implementation that itself relies on a
special TASK state would loose TASK_TRACED/TASK_STOPPED and will
result in misbehaviour.
As such, add additional state to task->jobctl to track this state
outside of task->__state.
NOTE: this doesn't actually fix anything yet, just adds extra state.
--EWB
* didn't add a unnecessary newline in signal.h
* Update t->jobctl in signal_wake_up and ptrace_signal_wake_up
instead of in signal_wake_up_state. This prevents the clearing
of TASK_STOPPED and TASK_TRACED from getting lost.
* Added warnings if JOBCTL_STOPPED or JOBCTL_TRACED are not cleared
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220421150654.757693825@infradead.org
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-12-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
||
|
Eric W. Biederman
|
2500ad1c7f |
ptrace: Don't change __state
Stop playing with tsk->__state to remove TASK_WAKEKILL while a ptrace command is executing. Instead remove TASK_WAKEKILL from the definition of TASK_TRACED, and implement a new jobctl flag TASK_PTRACE_FROZEN. This new flag is set in jobctl_freeze_task and cleared when ptrace_stop is awoken or in jobctl_unfreeze_task (when ptrace_stop remains asleep). In signal_wake_up add __TASK_TRACED to state along with TASK_WAKEKILL when the wake up is for a fatal signal. Skip adding __TASK_TRACED when TASK_PTRACE_FROZEN is not set. This has the same effect as changing TASK_TRACED to __TASK_TRACED as all of the wake_ups that use TASK_KILLABLE go through signal_wake_up. Handle a ptrace_stop being called with a pending fatal signal. Previously it would have been handled by schedule simply failing to sleep. As TASK_WAKEKILL is no longer part of TASK_TRACED schedule will sleep with a fatal_signal_pending. The code in signal_wake_up guarantees that the code will be awaked by any fatal signal that codes after TASK_TRACED is set. Previously the __state value of __TASK_TRACED was changed to TASK_RUNNING when woken up or back to TASK_TRACED when the code was left in ptrace_stop. Now when woken up ptrace_stop now clears JOBCTL_PTRACE_FROZEN and when left sleeping ptrace_unfreezed_traced clears JOBCTL_PTRACE_FROZEN. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-10-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
57b6de08b5 |
ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs
Long ago and far away there was a BUG_ON at the start of ptrace_stop
that did "BUG_ON(!(current->ptrace & PT_PTRACED));" [1]. The BUG_ON
had never triggered but examination of the code showed that the BUG_ON
could actually trigger. To complement removing the BUG_ON an attempt
to better handle the race was added.
The code detected the tracer had gone away and did not call
do_notify_parent_cldstop. The code also attempted to prevent
ptrace_report_syscall from sending spurious SIGTRAPs when the tracer
went away.
The code to detect when the tracer had gone away before sending a
signal to tracer was a legitimate fix and continues to work to this
date.
The code to prevent sending spurious SIGTRAPs is a failure. At the
time and until today the code only catches it when the tracer goes
away after siglock is dropped and before read_lock is acquired. If
the tracer goes away after read_lock is dropped a spurious SIGTRAP can
still be sent to the tracee. The tracer going away after read_lock
is dropped is the far likelier case as it is the bigger window.
Given that the attempt to prevent the generation of a SIGTRAP was a
failure and continues to be a failure remove the code that attempts to
do that. This simplifies the code in ptrace_stop and makes
ptrace_stop much easier to reason about.
To successfully deal with the tracer going away, all of the tracer's
instrumentation of the child would need to be removed, and reliably
detecting when the tracer has set a signal to continue with would need
to be implemented.
[1] 66519f549ae5 ("[PATCH] fix ptracer death race yielding bogus BUG_ON")
History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-9-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
|
||
|
Eric W. Biederman
|
cb3c19c93d |
signal: Use lockdep_assert_held instead of assert_spin_locked
The distinction is that assert_spin_locked() checks if the lock is held *by*anyone* whereas lockdep_assert_held() asserts the current context holds the lock. Also, the check goes away if you build without lockdep. Suggested-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/Ympr/+PX4XgT/UKU@hirez.programming.kicks-ass.net Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-6-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
e71ba12407 |
signal: Replace __group_send_sig_info with send_signal_locked
The function __group_send_sig_info is just a light wrapper around send_signal_locked with one parameter fixed to a constant value. As the wrapper adds no real value update the code to directly call the wrapped function. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-2-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
157cc18122 |
signal: Rename send_signal send_signal_locked
Rename send_signal and __send_signal to send_signal_locked and __send_signal_locked to make send_signal usable outside of signal.c. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-1-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
Marco Elver
|
78ed93d72d |
signal: Deliver SIGTRAP on perf event asynchronously if blocked
With SIGTRAP on perf events, we have encountered termination of
processes due to user space attempting to block delivery of SIGTRAP.
Consider this case:
<set up SIGTRAP on a perf event>
...
sigset_t s;
sigemptyset(&s);
sigaddset(&s, SIGTRAP | <and others>);
sigprocmask(SIG_BLOCK, &s, ...);
...
<perf event triggers>
When the perf event triggers, while SIGTRAP is blocked, force_sig_perf()
will force the signal, but revert back to the default handler, thus
terminating the task.
This makes sense for error conditions, but not so much for explicitly
requested monitoring. However, the expectation is still that signals
generated by perf events are synchronous, which will no longer be the
case if the signal is blocked and delivered later.
To give user space the ability to clearly distinguish synchronous from
asynchronous signals, introduce siginfo_t::si_perf_flags and
TRAP_PERF_FLAG_ASYNC (opted for flags in case more binary information is
required in future).
The resolution to the problem is then to (a) no longer force the signal
(avoiding the terminations), but (b) tell user space via si_perf_flags
if the signal was synchronous or not, so that such signals can be
handled differently (e.g. let user space decide to ignore or consider
the data imprecise).
The alternative of making the kernel ignore SIGTRAP on perf events if
the signal is blocked may work for some usecases, but likely causes
issues in others that then have to revert back to interception of
sigprocmask() (which we want to avoid). [ A concrete example: when using
breakpoint perf events to track data-flow, in a region of code where
signals are blocked, data-flow can no longer be tracked accurately.
When a relevant asynchronous signal is received after unblocking the
signal, the data-flow tracking logic needs to know its state is
imprecise. ]
Fixes:
|
||
Thomas Gleixner
|
7dd5ad2d3e |
Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels"
Revert commit
|
||
|
Linus Torvalds
|
1930a6e739 |
ptrace: Cleanups for v5.18
This set of changes removes tracehook.h, moves modification of all of
the ptrace fields inside of siglock to remove races, adds a missing
permission check to ptrace.c
The removal of tracehook.h is quite significant as it has been a major
source of confusion in recent years. Much of that confusion was
around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled
making the semantics clearer).
For people who don't know tracehook.h is a vestiage of an attempt to
implement uprobes like functionality that was never fully merged, and
was later superseeded by uprobes when uprobes was merged. For many
years now we have been removing what tracehook functionaly a little
bit at a time. To the point where now anything left in tracehook.h is
some weird strange thing that is difficult to understand.
Eric W. Biederman (15):
ptrace: Move ptrace_report_syscall into ptrace.h
ptrace/arm: Rename tracehook_report_syscall report_syscall
ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
ptrace: Remove arch_syscall_{enter,exit}_tracehook
ptrace: Remove tracehook_signal_handler
task_work: Remove unnecessary include from posix_timers.h
task_work: Introduce task_work_pending
task_work: Call tracehook_notify_signal from get_signal on all architectures
task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
resume_user_mode: Move to resume_user_mode.h
tracehook: Remove tracehook.h
ptrace: Move setting/clearing ptrace_message into ptrace_stop
ptrace: Return the signal to continue with from ptrace_stop
Jann Horn (1):
ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
Yang Li (1):
ptrace: Remove duplicated include in ptrace.c
MAINTAINERS | 1 -
arch/Kconfig | 5 +-
arch/alpha/kernel/ptrace.c | 5 +-
arch/alpha/kernel/signal.c | 4 +-
arch/arc/kernel/ptrace.c | 5 +-
arch/arc/kernel/signal.c | 4 +-
arch/arm/kernel/ptrace.c | 12 +-
arch/arm/kernel/signal.c | 4 +-
arch/arm64/kernel/ptrace.c | 14 +--
arch/arm64/kernel/signal.c | 4 +-
arch/csky/kernel/ptrace.c | 5 +-
arch/csky/kernel/signal.c | 4 +-
arch/h8300/kernel/ptrace.c | 5 +-
arch/h8300/kernel/signal.c | 4 +-
arch/hexagon/kernel/process.c | 4 +-
arch/hexagon/kernel/signal.c | 1 -
arch/hexagon/kernel/traps.c | 6 +-
arch/ia64/kernel/process.c | 4 +-
arch/ia64/kernel/ptrace.c | 6 +-
arch/ia64/kernel/signal.c | 1 -
arch/m68k/kernel/ptrace.c | 5 +-
arch/m68k/kernel/signal.c | 4 +-
arch/microblaze/kernel/ptrace.c | 5 +-
arch/microblaze/kernel/signal.c | 4 +-
arch/mips/kernel/ptrace.c | 5 +-
arch/mips/kernel/signal.c | 4 +-
arch/nds32/include/asm/syscall.h | 2 +-
arch/nds32/kernel/ptrace.c | 5 +-
arch/nds32/kernel/signal.c | 4 +-
arch/nios2/kernel/ptrace.c | 5 +-
arch/nios2/kernel/signal.c | 4 +-
arch/openrisc/kernel/ptrace.c | 5 +-
arch/openrisc/kernel/signal.c | 4 +-
arch/parisc/kernel/ptrace.c | 7 +-
arch/parisc/kernel/signal.c | 4 +-
arch/powerpc/kernel/ptrace/ptrace.c | 8 +-
arch/powerpc/kernel/signal.c | 4 +-
arch/riscv/kernel/ptrace.c | 5 +-
arch/riscv/kernel/signal.c | 4 +-
arch/s390/include/asm/entry-common.h | 1 -
arch/s390/kernel/ptrace.c | 1 -
arch/s390/kernel/signal.c | 5 +-
arch/sh/kernel/ptrace_32.c | 5 +-
arch/sh/kernel/signal_32.c | 4 +-
arch/sparc/kernel/ptrace_32.c | 5 +-
arch/sparc/kernel/ptrace_64.c | 5 +-
arch/sparc/kernel/signal32.c | 1 -
arch/sparc/kernel/signal_32.c | 4 +-
arch/sparc/kernel/signal_64.c | 4 +-
arch/um/kernel/process.c | 4 +-
arch/um/kernel/ptrace.c | 5 +-
arch/x86/kernel/ptrace.c | 1 -
arch/x86/kernel/signal.c | 5 +-
arch/x86/mm/tlb.c | 1 +
arch/xtensa/kernel/ptrace.c | 5 +-
arch/xtensa/kernel/signal.c | 4 +-
block/blk-cgroup.c | 2 +-
fs/coredump.c | 1 -
fs/exec.c | 1 -
fs/io-wq.c | 6 +-
fs/io_uring.c | 11 +-
fs/proc/array.c | 1 -
fs/proc/base.c | 1 -
include/asm-generic/syscall.h | 2 +-
include/linux/entry-common.h | 47 +-------
include/linux/entry-kvm.h | 2 +-
include/linux/posix-timers.h | 1 -
include/linux/ptrace.h | 81 ++++++++++++-
include/linux/resume_user_mode.h | 64 ++++++++++
include/linux/sched/signal.h | 17 +++
include/linux/task_work.h | 5 +
include/linux/tracehook.h | 226 -----------------------------------
include/uapi/linux/ptrace.h | 2 +-
kernel/entry/common.c | 19 +--
kernel/entry/kvm.c | 9 +-
kernel/exit.c | 3 +-
kernel/livepatch/transition.c | 1 -
kernel/ptrace.c | 47 +++++---
kernel/seccomp.c | 1 -
kernel/signal.c | 62 +++++-----
kernel/task_work.c | 4 +-
kernel/time/posix-cpu-timers.c | 1 +
mm/memcontrol.c | 2 +-
security/apparmor/domain.c | 1 -
security/selinux/hooks.c | 1 -
85 files changed, 372 insertions(+), 495 deletions(-)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace cleanups from Eric Biederman:
"This set of changes removes tracehook.h, moves modification of all of
the ptrace fields inside of siglock to remove races, adds a missing
permission check to ptrace.c
The removal of tracehook.h is quite significant as it has been a major
source of confusion in recent years. Much of that confusion was around
task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the
semantics clearer).
For people who don't know tracehook.h is a vestiage of an attempt to
implement uprobes like functionality that was never fully merged, and
was later superseeded by uprobes when uprobes was merged. For many
years now we have been removing what tracehook functionaly a little
bit at a time. To the point where anything left in tracehook.h was
some weird strange thing that was difficult to understand"
* tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ptrace: Remove duplicated include in ptrace.c
ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
ptrace: Return the signal to continue with from ptrace_stop
ptrace: Move setting/clearing ptrace_message into ptrace_stop
tracehook: Remove tracehook.h
resume_user_mode: Move to resume_user_mode.h
resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
task_work: Call tracehook_notify_signal from get_signal on all architectures
task_work: Introduce task_work_pending
task_work: Remove unnecessary include from posix_timers.h
ptrace: Remove tracehook_signal_handler
ptrace: Remove arch_syscall_{enter,exit}_tracehook
ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
ptrace/arm: Rename tracehook_report_syscall report_syscall
ptrace: Move ptrace_report_syscall into ptrace.h
|
||
|
Eric W. Biederman
|
6487d1dab8 |
ptrace: Return the signal to continue with from ptrace_stop
The signal a task should continue with after a ptrace stop is inconsistently read, cleared, and sent. Solve this by reading and clearing the signal to be sent in ptrace_stop. In an ideal world everything except ptrace_signal would share a common implementation of continuing with the signal, so ptracers could count on the signal they ask to continue with actually being delivered. For now retain bug compatibility and just return with the signal number the ptracer requested the code continue with. Link: https://lkml.kernel.org/r/875yoe7qdp.fsf_-_@email.froward.int.ebiederm.org Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
336d4b814b |
ptrace: Move setting/clearing ptrace_message into ptrace_stop
Today ptrace_message is easy to overlook as it not a core part of ptrace_stop. It has been overlooked so much that there are places that set ptrace_message and don't clear it, and places that never set it. So if you get an unlucky sequence of events the ptracer may be able to read a ptrace_message that does not apply to the current ptrace stop. Move setting of ptrace_message into ptrace_stop so that it always gets set before the stop, and always gets cleared after the stop. This prevents non-sense from being reported to userspace and makes ptrace_message more visible in the ptrace helper functions so that kernel developers can see it. Link: https://lkml.kernel.org/r/87bky67qfv.fsf_-_@email.froward.int.ebiederm.org Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
355f841a3f |
tracehook: Remove tracehook.h
Now that all of the definitions have moved out of tracehook.h into ptrace.h, sched/signal.h, resume_user_mode.h there is nothing left in tracehook.h so remove it. Update the few files that were depending upon tracehook.h to bring in definitions to use the headers they need directly. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-13-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
8ba62d3794 |
task_work: Call tracehook_notify_signal from get_signal on all architectures
Always handle TIF_NOTIFY_SIGNAL in get_signal. With commit
|
||
|
Eric W. Biederman
|
7f62d40d9c |
task_work: Introduce task_work_pending
Wrap the test of task->task_works in a helper function to make it clear what is being tested. All of the other readers of task->task_work use READ_ONCE and this is even necessary on current as other processes can update task->task_work. So for consistency I have added READ_ONCE into task_work_pending. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-7-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
c145137dc9 |
ptrace: Remove tracehook_signal_handler
The two line function tracehook_signal_handler is only called from signal_delivered. Expand it inline in signal_delivered and remove it. Just to make it easier to understand what is going on. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20220309162454.123006-5-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Oleg Nesterov
|
bf9ad37dc8 |
signal, x86: Delay calling signals in atomic on RT enabled kernels
On x86_64 we must disable preemption before we enable interrupts for stack faults, int3 and debugging, because the current task is using a per CPU debug stack defined by the IST. If we schedule out, another task can come in and use the same stack and cause the stack to be corrupted and crash the kernel on return. When CONFIG_PREEMPT_RT is enabled, spinlock_t locks become sleeping, and one of these is the spin lock used in signal handling. Some of the debug code (int3) causes do_trap() to send a signal. This function calls a spinlock_t lock that has been converted to a sleeping lock. If this happens, the above issues with the corrupted stack is possible. Instead of calling the signal right away, for PREEMPT_RT and x86, the signal information is stored on the stacks task_struct and TIF_NOTIFY_RESUME is set. Then on exit of the trap, the signal resume code will send the signal when preemption is enabled. [ rostedt: Switched from #ifdef CONFIG_PREEMPT_RT to ARCH_RT_DELAYS_SIGNAL_SEND and added comments to the code. ] [bigeasy: Add on 32bit as per Yang Shi, minor rewording. ] [ tglx: Use a config option ] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/Ygq5aBB/qMQw6aP5@linutronix.de |
||
Kees Cook
|
5c72263ef2 |
signal: HANDLER_EXIT should clear SIGNAL_UNKILLABLE
Fatal SIGSYS signals (i.e. seccomp RET_KILL_* syscall filter actions)
were not being delivered to ptraced pid namespace init processes. Make
sure the SIGNAL_UNKILLABLE doesn't get set for these cases.
Reported-by: Robert Święcki <robert@swiecki.net>
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Fixes:
|
||
|
Linus Torvalds
|
35ce8ae9ae |
Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull signal/exit/ptrace updates from Eric Biederman:
"This set of changes deletes some dead code, makes a lot of cleanups
which hopefully make the code easier to follow, and fixes bugs found
along the way.
The end-game which I have not yet reached yet is for fatal signals
that generate coredumps to be short-circuit deliverable from
complete_signal, for force_siginfo_to_task not to require changing
userspace configured signal delivery state, and for the ptrace stops
to always happen in locations where we can guarantee on all
architectures that the all of the registers are saved and available on
the stack.
Removal of profile_task_ext, profile_munmap, and profile_handoff_task
are the big successes for dead code removal this round.
A bunch of small bug fixes are included, as most of the issues
reported were small enough that they would not affect bisection so I
simply added the fixes and did not fold the fixes into the changes
they were fixing.
There was a bug that broke coredumps piped to systemd-coredump. I
dropped the change that caused that bug and replaced it entirely with
something much more restrained. Unfortunately that required some
rebasing.
Some successes after this set of changes: There are few enough calls
to do_exit to audit in a reasonable amount of time. The lifetime of
struct kthread now matches the lifetime of struct task, and the
pointer to struct kthread is no longer stored in set_child_tid. The
flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
removed. Issues where task->exit_code was examined with
signal->group_exit_code should been examined were fixed.
There are several loosely related changes included because I am
cleaning up and if I don't include them they will probably get lost.
The original postings of these changes can be found at:
https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org
https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org
https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org
I trimmed back the last set of changes to only the obviously correct
once. Simply because there was less time for review than I had hoped"
* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
ptrace/m68k: Stop open coding ptrace_report_syscall
ptrace: Remove unused regs argument from ptrace_report_syscall
ptrace: Remove second setting of PT_SEIZED in ptrace_attach
taskstats: Cleanup the use of task->exit_code
exit: Use the correct exit_code in /proc/<pid>/stat
exit: Fix the exit_code for wait_task_zombie
exit: Coredumps reach do_group_exit
exit: Remove profile_handoff_task
exit: Remove profile_task_exit & profile_munmap
signal: clean up kernel-doc comments
signal: Remove the helper signal_group_exit
signal: Rename group_exit_task group_exec_task
coredump: Stop setting signal->group_exit_task
signal: Remove SIGNAL_GROUP_COREDUMP
signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
signal: Make coredump handling explicit in complete_signal
signal: Have prepare_signal detect coredumps using signal->core_state
signal: Have the oom killer detect coredumps using signal->core_state
exit: Move force_uaccess back into do_exit
exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
...
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Randy Dunlap
|
6410349ea5 |
signal: clean up kernel-doc comments
Fix kernel-doc warnings in kernel/signal.c: kernel/signal.c:1830: warning: Function parameter or member 'force_coredump' not described in 'force_sig_seccomp' kernel/signal.c:2873: warning: missing initial short description on line: * signal_delivered - Also add a closing parenthesis to the comments in signal_delivered(). Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Richard Weinberger <richard@nod.at> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Marco Elver <elver@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20211222031027.29694-1-rdunlap@infradead.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> |
||
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Eric W. Biederman
|
49697335e0 |
signal: Remove the helper signal_group_exit
This helper is misleading. It tests for an ongoing exec as well as the process having received a fatal signal. Sometimes it is appropriate to treat an on-going exec differently than a process that is shutting down due to a fatal signal. In particular taking the fast path out of exit_signals instead of retargeting signals is not appropriate during exec, and not changing the the exit code in do_group_exit during exec. Removing the helper makes it more obvious what is going on as both cases must be coded for explicitly. While removing the helper fix the two cases where I have observed using signal_group_exit resulted in the wrong result. In exit_signals only test for SIGNAL_GROUP_EXIT so that signals are retargetted during an exec. In do_group_exit use 0 as the exit code during an exec as de_thread does not set group_exit_code. As best as I can determine group_exit_code has been is set to 0 most of the time during de_thread. During a thread group stop group_exit_code is set to the stop signal and when the thread group receives SIGCONT group_exit_code is reset to 0. Link: https://lkml.kernel.org/r/20211213225350.27481-8-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
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Eric W. Biederman
|
2f824d4d19 |
signal: Remove SIGNAL_GROUP_COREDUMP
After the previous cleanups "signal->core_state" is set whenever SIGNAL_GROUP_COREDUMP is set and "signal->core_state" is tested whenver the code wants to know if a coredump is in progress. The remaining tests of SIGNAL_GROUP_COREDUMP also test to see if SIGNAL_GROUP_EXIT is set. Similarly the only place that sets SIGNAL_GROUP_COREDUMP also sets SIGNAL_GROUP_EXIT. Which makes SIGNAL_GROUP_COREDUMP unecessary and redundant. So stop setting SIGNAL_GROUP_COREDUMP, stop testing SIGNAL_GROUP_COREDUMP, and remove it's definition. With the setting of SIGNAL_GROUP_COREDUMP gone, coredump_finish no longer needs to clear SIGNAL_GROUP_COREDUMP out of signal->flags by setting SIGNAL_GROUP_EXIT. Link: https://lkml.kernel.org/r/20211213225350.27481-5-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Eric W. Biederman
|
7ba03471ac |
signal: Make coredump handling explicit in complete_signal
Ever since commit
|
||
|
Eric W. Biederman
|
a0287db0f1 |
signal: Have prepare_signal detect coredumps using signal->core_state
In preparation for removing the flag SIGNAL_GROUP_COREDUMP, change prepare_signal to test signal->core_state instead of the flag SIGNAL_GROUP_COREDUMP. Both fields are protected by siglock and both live in signal_struct so there are no real tradeoffs here, just a change to which field is being tested. Link: https://lkml.kernel.org/r/20211213225350.27481-1-ebiederm@xmission.com Link: https://lkml.kernel.org/r/875yqu14co.fsf_-_@email.froward.int.ebiederm.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
Chang S. Bae
|
6c3118c321 |
signal: Skip the altstack update when not needed
== Background ==
Support for large, "dynamic" fpstates was recently merged. This
included code to ensure that sigaltstacks are sufficiently sized for
these large states. A new lock was added to remove races between
enabling large features and setting up sigaltstacks.
== Problem ==
The new lock (sigaltstack_lock()) is acquired in the sigreturn path
before restoring the old sigaltstack. Unfortunately, contention on the
new lock causes a measurable signal handling performance regression [1].
However, the common case is that no *changes* are made to the
sigaltstack state at sigreturn.
== Solution ==
do_sigaltstack() acquires sigaltstack_lock() and is used for both
sys_sigaltstack() and restoring the sigaltstack in sys_sigreturn().
Check for changes to the sigaltstack before taking the lock. If no
changes were made, return before acquiring the lock.
This removes lock contention from the common-case sigreturn path.
[1] https://lore.kernel.org/lkml/20211207012128.GA16074@xsang-OptiPlex-9020/
Fixes:
|
||
|
Eric W. Biederman
|
9d3f401c52 |
Merge SA_IMMUTABLE-fixes-for-v5.16-rc2
I completed the first batch of signal changes for v5.17 against
v5.16-rc1 before the SA_IMMUTABLE fixes where completed. Which leaves
me with two lines of development that I want on my signal development
branch both rooted at v5.16-rc1. Especially as I am hoping
to reach the point of being able to remove SA_IMMUTABLE.
Linus merged my SA_IMUTABLE fixes as:
|