diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2025-01-09 14:04:18 +0000 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-01-14 13:02:40 +0100 |
| commit | 2114796ca041f0d3e79e5dd165219b940b23c540 (patch) | |
| tree | 7895b729c1430a2299e2fea85efdf2428021d517 | |
| parent | eeed9150411a63dd0611490cf31fdae681427918 (diff) | |
x86/kexec: Mark machine_kexec() with __nocfi
A recent commit caused the relocate_kernel() function to be invoked through
a function pointer, but it does not have CFI information. The resulting trap
occurs after the IDT and GDT have been invalidated, leading to a triple-fault
if CONFIG_CFI_CLANG is enabled.
Using SYM_TYPED_FUNC_START() to provide the CFI information looks like it will
require a prolonged battle with objtool. And is fairly pointless anyway, as
the actual signature comes from a __kcfi_typeid_… symbol emitted from the
C code based on the function prototype it thinks that relocate_kernel has,
rendering the check somewhat tautological.
The simple fix is just to mark machine_kexec() with __nocfi.
Fixes: eeebbde57113 ("x86/kexec: Invoke copy of relocate_kernel() instead of the original")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250109140757.2841269-7-dwmw2@infradead.org
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 9232ad1562c8..1440f792a86d 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -342,7 +342,7 @@ void machine_kexec_cleanup(struct kimage *image) * Do not allocate memory (or fail in any way) in machine_kexec(). * We are past the point of no return, committed to rebooting now. */ -void machine_kexec(struct kimage *image) +void __nocfi machine_kexec(struct kimage *image) { unsigned long (*relocate_kernel_ptr)(unsigned long indirection_page, unsigned long pa_control_page, |