[PATCH 1/1] Documentation/x86/boot: Correct algorithm for runtime start address
From: Adrian Huang <hidden>
Date: 2021-03-07 14:25:22
Also in:
lkml
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
From: Adrian Huang <redacted>
Commit 8ab3820fd5b2 ("x86, kaslr: Return location from decompress_kernel")
enforces CONFIG_PHYSICAL_START as the minimum relocation address when
the kernel option CONFIG_RELOCATABLE is enabled. This change should be
included accordingly.
Signed-off-by: Adrian Huang <redacted>
Cc: Kees Cook <redacted>
---
Documentation/x86/boot.rst | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index fc844913dece..808ea181ca40 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst@@ -894,10 +894,16 @@ Offset/size: 0x260/4 The kernel runtime start address is determined by the following algorithm:: - if (relocatable_kernel) - runtime_start = align_up(load_address, kernel_alignment) - else - runtime_start = pref_address + if (relocatable_kernel) { + runtime_start = align_up(load_address, kernel_alignment); + + /* pref_address is the minimum relocation address */ + if (runtime_start < pref_address) + runtime_start = pref_address; + } else { + /* Adhere to the statement describing in field 'pref_address' */ + runtime_start = pref_address; + } ============ =============== Field name: handover_offset
--
2.17.1