From: Kees Cook keescook@chromium.org
[ Upstream commit 392bef709659abea614abfe53cf228e7a59876a4 ]
When building x86 with Clang LTO and CFI, CFI jump regions are automatically added to the end of the .text section late in linking. As a result, the _etext position was being labelled before the appended jump regions, causing confusion about where the boundaries of the executable region actually are in the running kernel, and broke at least the fault injection code. This moves the _etext mark to outside (and immediately after) the .text area, as it already the case on other architectures (e.g. arm64, arm).
Reported-and-tested-by: Sami Tolvanen samitolvanen@google.com Signed-off-by: Kees Cook keescook@chromium.org Cc: Borislav Petkov bp@suse.de Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/20190423183827.GA4012@beast Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/vmlinux.lds.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 55f04875293fa..51b772f9d886a 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -111,11 +111,11 @@ SECTIONS *(.text.__x86.indirect_thunk) __indirect_thunk_end = .; #endif - - /* End of text section */ - _etext = .; } :text = 0x9090
+ /* End of text section */ + _etext = .; + NOTES :text :note
EXCEPTION_TABLE(16) :text = 0x9090