linux.git/kernel/stacktrace.c, branch v6.18.21

stacktrace: fix kernel-doc typo

2023-12-29T20:22:29+00:00

Change @task to @tsk to prevent kernel-doc warnings:

kernel/stacktrace.c:138: warning: Excess function parameter 'task' description in 'stack_trace_save_tsk'
kernel/stacktrace.c:138: warning: Function parameter or member 'tsk' not described in 'stack_trace_save_tsk'

Link: https://lkml.kernel.org/r/20231220054945.17663-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton

stacktrace: Export stack_trace_save_tsk

2023-09-12T03:59:47+00:00

The bcachefs module wants it, and there doesn't seem to be any
reason it shouldn't be exported like the other functions.

Signed-off-by: Christopher James Halse Rogers 
Signed-off-by: Kent Overstreet

uaccess: remove CONFIG_SET_FS

2022-02-25T08:36:06+00:00

There are no remaining callers of set_fs(), so CONFIG_SET_FS
can be removed globally, along with the thread_info field and
any references to it.

This turns access_ok() into a cheaper check against TASK_SIZE_MAX.

As CONFIG_SET_FS is now gone, drop all remaining references to
set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel().

Acked-by: Sam Ravnborg  # for sparc32 changes
Acked-by: "Eric W. Biederman" 
Tested-by: Sergey Matyukevich  # for arc changes
Acked-by: Stafford Horne  # [openrisc, asm-generic]
Acked-by: Dinh Nguyen 
Signed-off-by: Arnd Bergmann

stacktrace: move filter_irq_stacks() to kernel/stacktrace.c

2021-11-06T20:30:43+00:00

filter_irq_stacks() has little to do with the stackdepot implementation,
except that it is usually used by users (such as KASAN) of stackdepot to
reduce the stack trace.

However, filter_irq_stacks() itself is not useful without a stack trace
as obtained by stack_trace_save() and friends.

Therefore, move filter_irq_stacks() to kernel/stacktrace.c, so that new
users of filter_irq_stacks() do not have to start depending on
STACKDEPOT only for filter_irq_stacks().

Link: https://lkml.kernel.org/r/20210923104803.2620285-1-elver@google.com
Signed-off-by: Marco Elver 
Acked-by: Dmitry Vyukov 
Cc: Alexander Potapenko 
Cc: Jann Horn 
Cc: Aleksandr Nogikh 
Cc: Taras Madan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

stacktrace: Remove reliable argument from arch_stack_walk() callback

2020-09-18T13:24:16+00:00

Currently the callback passed to arch_stack_walk() has an argument called
reliable passed to it to indicate if the stack entry is reliable, a comment
says that this is used by some printk() consumers. However in the current
kernel none of the arch_stack_walk() implementations ever set this flag to
true and the only callback implementation we have is in the generic
stacktrace code which ignores the flag. It therefore appears that this
flag is redundant so we can simplify and clarify things by removing it.

Signed-off-by: Mark Brown 
Reviewed-by: Miroslav Benes 
Link: https://lore.kernel.org/r/20200914153409.25097-2-broonie@kernel.org
Signed-off-by: Will Deacon

uaccess: add force_uaccess_{begin,end} helpers

2020-08-12T17:57:59+00:00

Add helpers to wrap the get_fs/set_fs magic for undoing any damange done
by set_fs(KERNEL_DS).  There is no real functional benefit, but this
documents the intent of these calls better, and will allow stubbing the
functions out easily for kernels builds that do not allow address space
overrides in the future.

[hch@lst.de: drop two incorrect hunks, fix a commit log typo]
  Link: http://lkml.kernel.org/r/20200714105505.935079-6-hch@lst.de

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Acked-by: Linus Torvalds 
Acked-by: Mark Rutland 
Acked-by: Greentime Hu 
Acked-by: Geert Uytterhoeven 
Cc: Nick Hu 
Cc: Vincent Chen 
Cc: Paul Walmsley 
Cc: Palmer Dabbelt 
Link: http://lkml.kernel.org/r/20200710135706.537715-6-hch@lst.de
Signed-off-by: Linus Torvalds

stacktrace: Get rid of unneeded '!!' pattern

2019-11-11T09:30:59+00:00

My commit b0c51f158455 ("stacktrace: Don't skip first entry on
noncurrent tasks") adds one or zero to skipnr by "!!(current == tsk)".

But the C99 standard says:

  The == (equal to) and != (not equal to) operators are
  ...
  Each of the operators yields 1 if the specified relation is true and 0
  if it is false.

So there is no need to prepend the above expression by "!!" -- remove it.

Reported-by: Joe Perches 
Signed-off-by: Jiri Slaby 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20191111092647.27419-1-jslaby@suse.cz
Signed-off-by: Ingo Molnar

stacktrace: Don't skip first entry on noncurrent tasks

2019-11-04T20:19:25+00:00

When doing cat /proc//stack, the output is missing the first entry.
When the current code walks the stack starting in stack_trace_save_tsk,
it skips all scheduler functions (that's OK) plus one more function. But
this one function should be skipped only for the 'current' task as it is
stack_trace_save_tsk proper.

The original code (before the common infrastructure) skipped one
function only for the 'current' task -- see save_stack_trace_tsk before
3599fe12a125. So do so also in the new infrastructure now.

Fixes: 214d8ca6ee85 ("stacktrace: Provide common infrastructure")
Signed-off-by: Jiri Slaby 
Signed-off-by: Thomas Gleixner 
Tested-by: Michal Suchanek 
Acked-by: Josh Poimboeuf 
Link: https://lkml.kernel.org/r/20191030072545.19462-1-jslaby@suse.cz

stacktrace: Constify 'entries' arguments

2019-07-25T13:43:26+00:00

Make it clear to humans and to the compiler that the stack trace
('entries') arguments are not modified.

Signed-off-by: Bart Van Assche 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Waiman Long 
Cc: Will Deacon 
Link: https://lkml.kernel.org/r/20190722182443.216015-3-bvanassche@acm.org
Signed-off-by: Ingo Molnar

stacktrace: Force USER_DS for stack_trace_save_user()

2019-07-18T14:47:24+00:00

When walking userspace stacks, USER_DS needs to be set, otherwise
access_ok() will not function as expected.

Reported-by: Vegard Nossum 
Reported-by: Eiichi Tsukata 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Tested-by: Vegard Nossum 
Reviewed-by: Joel Fernandes (Google) 
Link: https://lkml.kernel.org/r/20190718085754.GM3402@hirez.programming.kicks-ass.net