arm64: Pull in task_stack_page() to Spectre-v4 mitigation code
authorWill Deacon <will@kernel.org>
Mon, 28 Sep 2020 13:06:50 +0000 (14:06 +0100)
committerWill Deacon <will@kernel.org>
Tue, 29 Sep 2020 15:08:17 +0000 (16:08 +0100)
commit5c8b0cbd9d6bac5f40943b5a7d8eac8cb86cbe7f
tree3e9ae69290100b5be0ec9bce0ed3243e26fe4e28
parent9ef2b48be9bba70ded9372fc81e678e707306060
arm64: Pull in task_stack_page() to Spectre-v4 mitigation code

The kbuild robot reports that we're relying on an implicit inclusion to
get a definition of task_stack_page() in the Spectre-v4 mitigation code,
which is not always in place for some configurations:

  | arch/arm64/kernel/proton-pack.c:329:2: error: implicit declaration of function 'task_stack_page' [-Werror,-Wimplicit-function-declaration]
  |         task_pt_regs(task)->pstate |= val;
  |         ^
  | arch/arm64/include/asm/processor.h:268:36: note: expanded from macro 'task_pt_regs'
  |         ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
  |                                           ^
  | arch/arm64/kernel/proton-pack.c:329:2: note: did you mean 'task_spread_page'?

Add the missing include to fix the build error.

Fixes: a44acf477220 ("arm64: Move SSBD prctl() handler alongside other spectre mitigation code")
Reported-by: Anthony Steinhauser <asteinhauser@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202009260013.Ul7AD29w%lkp@intel.com
Signed-off-by: Will Deacon <will@kernel.org>
arch/arm64/kernel/proton-pack.c