kernel/linux.git/include/linux/tracehook.h, branch v5.2.20

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193

2019-05-30T18:29:21+00:00

Based on 1 normalized pattern(s): this copyrighted material is made available to anyone wishing to use modify copy or redistribute it subject to the terms and conditions of the gnu general public license v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 45 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Richard Fontana Reviewed-by: Allison Randal Reviewed-by: Steve Winslow Reviewed-by: Alexios Zavras Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170027.342746075@linutronix.de Signed-off-by: Greg Kroah-Hartman

x86/ptrace: Fix documentation for tracehook_report_syscall_entry()

2018-11-12T03:53:27+00:00

tracehook_report_syscall_entry() is called not only if %TIF_SYSCALL_TRACE is set, but also if %TIF_SYSCALL_EMU is set, as appears from x86's entry code. Signed-off-by: Elvira Khabirova Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: ldv@altlinux.org Cc: oleg@redhat.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/20181110042209.26333972@akathisia Signed-off-by: Ingo Molnar

signal: Simplify tracehook_report_syscall_exit

2018-09-19T13:45:42+00:00

Replace user_single_step_siginfo with user_single_step_report that allocates siginfo structure on the stack and sends it. This allows tracehook_report_syscall_exit to become a simple if statement that calls user_single_step_report or ptrace_report_syscall depending on the value of step. Update the default helper function now called user_single_step_report to explicitly set si_code to SI_USER and to set si_uid and si_pid to 0. The default helper has always been doing this (using memset) but it was far from obvious. The powerpc helper can now just call force_sig_fault. The x86 helper can now just call send_sigtrap. Unfortunately the default implementation of user_single_step_report can not use force_sig_fault as it does not use a SIGTRAP si_code. So it has to carefully setup the siginfo and use use force_sig_info. The net result is code that is easier to understand and simpler to maintain. Ref: 85ec7fd9f8e5 ("ptrace: introduce user_single_step_siginfo() helper") Reviewed-by: Thomas Gleixner Signed-off-by: "Eric W. Biederman"

blkcg: add generic throttling mechanism

2018-07-09T15:07:54+00:00

Since IO can be issued from literally anywhere it's almost impossible to do throttling without having some sort of adverse effect somewhere else in the system because of locking or other dependencies. The best way to solve this is to do the throttling when we know we aren't holding any other kernel resources. Do this by tracking throttling in a per-blkg basis, and if we require throttling flag the task that it needs to check before it returns to user space and possibly sleep there. This is to address the case where a process is doing work that is generating IO that can't be throttled, whether that is directly with a lot of REQ_META IO, or indirectly by allocating so much memory that it is swamping the disk with REQ_SWAP. We can't use task_add_work as we don't want to induce a memory allocation in the IO path, so simply saving the request queue in the task and flagging it to do the notify_resume thing achieves the same result without the overhead of a memory allocation. Signed-off-by: Josef Bacik Acked-by: Tejun Heo Signed-off-by: Jens Axboe

signal: Ensure every siginfo we send has all bits initialized

2018-04-25T15:40:51+00:00

Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman"

memcg: punt high overage reclaim to return-to-userland path

2015-11-06T03:34:48+00:00

Currently, try_charge() tries to reclaim memory synchronously when the high limit is breached; however, if the allocation doesn't have __GFP_WAIT, synchronous reclaim is skipped. If a process performs only speculative allocations, it can blow way past the high limit. This is actually easily reproducible by simply doing "find /". slab/slub allocator tries speculative allocations first, so as long as there's memory which can be consumed without blocking, it can keep allocating memory regardless of the high limit. This patch makes try_charge() always punt the over-high reclaim to the return-to-userland path. If try_charge() detects that high limit is breached, it adds the overage to current->memcg_nr_pages_over_high and schedules execution of mem_cgroup_handle_over_high() which performs synchronous reclaim from the return-to-userland path. As long as kernel doesn't have a run-away allocation spree, this should provide enough protection while making kmemcg behave more consistently. It also has the following benefits. - All over-high reclaims can use GFP_KERNEL regardless of the specific gfp mask in use, e.g. GFP_NOFS, when the limit was breached. - It copes with prio inversion. Previously, a low-prio task with small memory.high might perform over-high reclaim with a bunch of locks held. If a higher prio task needed any of these locks, it would have to wait until the low prio task finished reclaim and released the locks. By handing over-high reclaim to the task exit path this issue can be avoided. Signed-off-by: Tejun Heo Acked-by: Michal Hocko Reviewed-by: Vladimir Davydov Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

tracehook_signal_handler: Remove sig, info, ka and regs

2014-08-06T11:03:43+00:00

These parameters are nowhere used, so we can remove them. Signed-off-by: Richard Weinberger

arch: Mass conversion of smp_mb__*()

2014-04-18T12:20:48+00:00

Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra Acked-by: Paul E. McKenney Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar

trim task_work: get rid of hlist

2012-07-22T19:57:55+00:00

layout based on Oleg's suggestion; single-linked list, task->task_works points to the last element, forward pointer from said last element points to head. I'd still prefer much more regular scheme with two pointers in task_work, but... Signed-off-by: Al Viro

keys: kill the dummy key_replace_session_keyring()

2012-05-24T02:11:31+00:00

After the previouse change key_replace_session_keyring() becomes a nop. Remove the dummy definition in key.h and update the callers in arch/*/kernel/signal.c. Signed-off-by: Oleg Nesterov Acked-by: David Howells Cc: Thomas Gleixner Cc: Richard Kuo Cc: Linus Torvalds Cc: Alexander Gordeev Cc: Chris Zankel Cc: David Smith Cc: "Frank Ch. Eigler" Cc: Geert Uytterhoeven Cc: Larry Woodman Cc: Peter Zijlstra Cc: Tejun Heo Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Al Viro