diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-04-09 21:16:01 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-04-09 21:29:11 +0200 |
| commit | 1fac13956e9877483ece9d090a62239cdfe9deb7 (patch) | |
| tree | f426ffb20b65b943526a5cb3cddaed426902ce5e /arch | |
| parent | f0df00ebc57f803603f2a2e0df197e51f06fbe90 (diff) | |
x86/ibt: Fix hibernate
Todd reported, and Len confirmed, that commit 582077c94052 ("x86/cfi:
Clean up linkage") broke S4 hiberate on a fair number of machines.
Turns out these machines trip #CP when trying to restore the image.
As it happens, the commit in question removes two ENDBR instructions
in the hibernate code, and clearly got it wrong.
Notably restore_image() does an indirect jump to
relocated_restore_code(), which is a relocated copy of
core_restore_code().
In turn, core_restore_code(), will at the end do an indirect jump to
restore_jump_address (r8), which is pointing at a relocated
restore_registers().
So both sites do indeed need to be ENDBR.
Fixes: 582077c94052 ("x86/cfi: Clean up linkage")
Reported-by: Todd Brandt <todd.e.brandt@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Todd Brandt <todd.e.brandt@intel.com>
Tested-by: Len Brown <len.brown@intel.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219998
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219998
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/power/hibernate_asm_64.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S index 8c534c36adfa..66f066b8feda 100644 --- a/arch/x86/power/hibernate_asm_64.S +++ b/arch/x86/power/hibernate_asm_64.S @@ -26,7 +26,7 @@ /* code below belongs to the image kernel */ .align PAGE_SIZE SYM_FUNC_START(restore_registers) - ANNOTATE_NOENDBR + ENDBR /* go back to the original page tables */ movq %r9, %cr3 @@ -120,7 +120,7 @@ SYM_FUNC_END(restore_image) /* code below has been relocated to a safe page */ SYM_FUNC_START(core_restore_code) - ANNOTATE_NOENDBR + ENDBR /* switch to temporary page tables */ movq %rax, %cr3 /* flush TLB */ |