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.orghttps://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.orghttps://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
...
When building ARCH=csky defconfig:
arch/csky/kernel/traps.c: In function 'die':
arch/csky/kernel/traps.c:112:17: error: implicit declaration of function
'make_dead_task' [-Werror=implicit-function-declaration]
112 | make_dead_task(SIGSEGV);
| ^~~~~~~~~~~~~~
The function's name is make_task_dead(), change it so there is no more
build error.
Fixes: 0e25498f8c ("exit: Add and use make_task_dead.")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lkml.kernel.org/r/20211227184851.2297759-4-nathan@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Fix typo which will cause fpe and privilege exception error.
Signed-off-by: Kelly Devilliv <kelly.devilliv@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
There is a prologue on page fault handler which marking pages dirty
and/or accessed in page attributes, but all of these have been
handled in handle_pte_fault.
- Add flush_tlb_one in vmalloc page fault instead of prologue.
- Using cmxchg_fixup C codes in do_page_fault instead of ASM one.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
This patch adds support for uprobes on csky architecture.
Just like kprobe, it support single-step and simulate instructions.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
This patch enable kprobes, kretprobes, ftrace interface. It utilized
software breakpoint and single step debug exceptions, instructions
simulation on csky.
We use USR_BKPT replace origin instruction, and the kprobe handler
prepares an excutable memory slot for out-of-line execution with a
copy of the original instruction being probed. Most of instructions
could be executed by single-step, but some instructions need origin
pc value to execute and we need software simulate these instructions.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
We should get psr value from regs->psr in stack, not directly get
it from phyiscal register then save the vector number in
tsk->trap_no.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
This round of csky subsystem gives two features (ASID algorithm update,
Perf pmu record support) and some fixups.
Feature:
- csky: Revert mmu ASID mechanism
- csky: Add new asid lib code from arm
- csky: Use generic asid algorithm to implement switch_mm
- csky: Improve tlb operation with help of asid
- csky: Init pmu as a device
- csky: Add count-width property for csky pmu
- csky: Add pmu interrupt support
- csky: Fix perf record in kernel/user space
- dt-bindings: csky: Add csky PMU bindings
Fixup:
- csky: Fixup no panic in kernel for some traps
- csky: Fixup some error count in 810 & 860.
- csky: Fixup abiv1 memset error
CI-Tested: https://gitlab.com/c-sky/buildroot/pipelines/68656845
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Merge tag 'csky-for-linus-5.3-rc1' of git://github.com/c-sky/csky-linux
Pull arch/csky pupdates from Guo Ren:
"This round of csky subsystem gives two features (ASID algorithm
update, Perf pmu record support) and some fixups.
ASID updates:
- Revert mmu ASID mechanism
- Add new asid lib code from arm
- Use generic asid algorithm to implement switch_mm
- Improve tlb operation with help of asid
Perf pmu record support:
- Init pmu as a device
- Add count-width property for csky pmu
- Add pmu interrupt support
- Fix perf record in kernel/user space
- dt-bindings: Add csky PMU bindings
Fixes:
- Fixup no panic in kernel for some traps
- Fixup some error count in 810 & 860.
- Fixup abiv1 memset error"
* tag 'csky-for-linus-5.3-rc1' of git://github.com/c-sky/csky-linux:
csky: Fixup abiv1 memset error
csky: Improve tlb operation with help of asid
csky: Use generic asid algorithm to implement switch_mm
csky: Add new asid lib code from arm
csky: Revert mmu ASID mechanism
dt-bindings: csky: Add csky PMU bindings
dt-bindings: interrupt-controller: Update csky mpintc
csky: Fixup some error count in 810 & 860.
csky: Fix perf record in kernel/user space
csky: Add pmu interrupt support
csky: Add count-width property for csky pmu
csky: Init pmu as a device
csky: Fixup no panic in kernel for some traps
csky: Select intc & timer drivers
These traps couldn't be hanppen in kernel and we must panic there not
send a signal to userspace.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
As synchronous exceptions really only make sense against the current
task (otherwise how are you synchronous) remove the task parameter
from from force_sig_fault to make it explicit that is what is going
on.
The two known exceptions that deliver a synchronous exception to a
stopped ptraced task have already been changed to
force_sig_fault_to_task.
The callers have been changed with the following emacs regular expression
(with obvious variations on the architectures that take more arguments)
to avoid typos:
force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)]
->
force_sig_fault(\1,\2,\3)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cleanup struct cpuinfo_csky and struct thread_struct, remove all esp0
related code. We could get pt_regs from sp and backtrace could use fp
in switch_stack.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Linus Torvalds