arm64: prep stack walkers for THREAD_INFO_IN_TASK
authorMark Rutland <mark.rutland@arm.com>
Thu, 3 Nov 2016 20:23:08 +0000 (20:23 +0000)
committerCatalin Marinas <catalin.marinas@arm.com>
Fri, 11 Nov 2016 18:25:44 +0000 (18:25 +0000)
commit9bbd4c56b0b642f04396da378296e68096d5afca
tree3748f98d16c323a04cf7c6dd208b2fc80bf311f8
parent2020a5ae7c8c2c8504565004915017507b135c63
arm64: prep stack walkers for THREAD_INFO_IN_TASK

When CONFIG_THREAD_INFO_IN_TASK is selected, task stacks may be freed
before a task is destroyed. To account for this, the stacks are
refcounted, and when manipulating the stack of another task, it is
necessary to get/put the stack to ensure it isn't freed and/or re-used
while we do so.

This patch reworks the arm64 stack walking code to account for this.
When CONFIG_THREAD_INFO_IN_TASK is not selected these perform no
refcounting, and this should only be a structural change that does not
affect behaviour.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/process.c
arch/arm64/kernel/stacktrace.c
arch/arm64/kernel/traps.c