linux-toradex.git/kernel/unwind, branch v7.0-rc7

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook

unwind_user/fp: Use dummies instead of ifdef

2025-12-17T12:31:07+00:00

This simplifies the code.   unwind_user_next_fp() does not need to
return -EINVAL if config option HAVE_UNWIND_USER_FP is disabled, as
unwind_user_start() will then not select this unwind method and
unwind_user_next() will therefore not call it.

Provide (1) a dummy definition of ARCH_INIT_USER_FP_FRAME, if the unwind
user method HAVE_UNWIND_USER_FP is not enabled, (2) a common fallback
definition of unwind_user_at_function_start() which returns false, and
(3) a common dummy definition of ARCH_INIT_USER_FP_ENTRY_FRAME.

Note that enabling the config option HAVE_UNWIND_USER_FP without
defining ARCH_INIT_USER_FP_FRAME triggers a compile error, which is
helpful when implementing support for this unwind user method in an
architecture.  Enabling the config option when providing an arch-
specific unwind_user_at_function_start() definition makes it necessary
to also provide an arch-specific ARCH_INIT_USER_FP_ENTRY_FRAME
definition.

Signed-off-by: Jens Remus 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20251208160352.1363040-3-jremus@linux.ibm.com

unwind_user: Enhance comments on get CFA, FP, and RA

2025-12-17T12:31:07+00:00

Move the comment "Get the Canonical Frame Address (CFA)" to the top
of the sequence of statements that actually get the CFA.  Reword the
comment "Find the Return Address (RA)" to "Get ...", as the statements
actually get the RA.  Add a respective comment to the statements that
get the FP.  This will be useful once future commits extend the logic
to get the RA and FP.

While at it align the comment on the "stack going in wrong direction"
check to the following one on the "address is word aligned" check.

Signed-off-by: Jens Remus 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20251208160352.1363040-2-jremus@linux.ibm.com

unwind_user/x86: Teach FP unwind about start of function

2025-10-29T09:29:58+00:00

When userspace is interrupted at the start of a function, before we
get a chance to complete the frame, unwind will miss one caller.

X86 has a uprobe specific fixup for this, add bits to the generic
unwinder to support this.

Suggested-by: Jens Remus 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20251024145156.GM4068168@noisy.programming.kicks-ass.net

unwind: Implement compat fp unwind

2025-10-29T09:29:57+00:00

It is important to be able to unwind compat tasks too.

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20250924080119.613695709@infradead.org

unwind: Simplify unwind_user_next_fp() alignment check

2025-10-29T09:29:57+00:00

  2^log_2(n) == n

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Steven Rostedt (Google) 
Link: https://patch.msgid.link/20250924080119.497867836@infradead.org

unwind: Make unwind_task_info::unwind_mask consistent

2025-10-29T09:29:57+00:00

The unwind_task_info::unwind_mask was manipulated using a mixture of:

  regular store
  WRITE_ONCE()
  try_cmpxchg()
  set_bit()
  atomic_long_*()

Clean up and make it consistently atomic_long_t.

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20250924080119.384384486@infradead.org

unwind: Simplify unwind_user_faultable()

2025-10-29T09:29:56+00:00

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20250924080119.271671514@infradead.org

unwind: Clarify calling context

2025-10-29T09:29:56+00:00

The get_cookie() function hard relies on IRQs being disabled, but this
isn't immediately obvious when reading the function.

Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Steven Rostedt (Google) 
Link: https://patch.msgid.link/20250924080119.122507632@infradead.org