diff options
| author |   David Woodhouse <dwmw@amazon.co.uk> | 2025-01-09 14:04:14 +0000 |
|---|---|---|
| committer |   Borislav Petkov (AMD) <bp@alien8.de> | 2025-01-14 12:52:47 +0100 |
| commit | 4d5f1da98f5e94ecc39d6e7a990db2efe0ae3810 (patch) | |
| tree | b3921df5393f13d355699d6cdba3a08cd1faa33d | |
| parent | x86/kexec: Disable global pages before writing to control page (diff) | |
| download | wireguard-linux-4d5f1da98f5e94ecc39d6e7a990db2efe0ae3810.tar.xz wireguard-linux-4d5f1da98f5e94ecc39d6e7a990db2efe0ae3810.zip | |
x86/kexec: Ensure preserve_context flag is set on return to kernel
The swap_pages() function will only actually *swap*, as its name implies, if
the preserve_context flag in the %r11 register is non-zero. On the way back
from a ::preserve_context kexec, ensure that the %r11 register is non-zero so
that the pages get swapped back.
Fixes: 9e5683e2d0b5 ("x86/kexec: Only swap pages for ::preserve_context mode")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250109140757.2841269-3-dwmw2@infradead.org
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 9bd601dd8659..6fce4b459652 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -220,6 +220,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) movq kexec_pa_table_page(%rip), %rax movq %rax, %cr3 lea PAGE_SIZE(%r8), %rsp + movl $1, %r11d /* Ensure preserve_context flag is set */ call swap_pages movq kexec_va_control_page(%rip), %rax addq $(virtual_mapped - relocate_kernel), %rax |