diff options
author | Dave Airlie <airlied@redhat.com> | 2023-08-24 07:26:06 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2023-08-24 07:26:06 +1000 |
commit | fdebffeba8b877368ddcc139c26278c1c97931a4 (patch) | |
tree | 5ebf85a3e26d55ea388aa7a8608222205a4d59ba /arch/x86/entry/entry_64.S | |
parent | cacaeb27ade4b793c456179bb6eda4592d206cd8 (diff) | |
parent | 706a741595047797872e669b3101429ab8d378ef (diff) |
BackMerge tag 'v6.5-rc7' into drm-next
Linux 6.5-rc7
This is needed for the CI stuff and the msm pull has fixes in it.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'arch/x86/entry/entry_64.S')
-rw-r--r-- | arch/x86/entry/entry_64.S | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 91f6818884fa..43606de22511 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -285,7 +285,15 @@ SYM_FUNC_END(__switch_to_asm) */ .pushsection .text, "ax" SYM_CODE_START(ret_from_fork_asm) - UNWIND_HINT_REGS + /* + * This is the start of the kernel stack; even through there's a + * register set at the top, the regset isn't necessarily coherent + * (consider kthreads) and one cannot unwind further. + * + * This ensures stack unwinds of kernel threads terminate in a known + * good state. + */ + UNWIND_HINT_END_OF_STACK ANNOTATE_NOENDBR // copy_thread CALL_DEPTH_ACCOUNT @@ -295,6 +303,12 @@ SYM_CODE_START(ret_from_fork_asm) movq %r12, %rcx /* fn_arg */ call ret_from_fork + /* + * Set the stack state to what is expected for the target function + * -- at this point the register set should be a valid user set + * and unwind should work normally. + */ + UNWIND_HINT_REGS jmp swapgs_restore_regs_and_return_to_usermode SYM_CODE_END(ret_from_fork_asm) .popsection |