From: Sami Tolvanen samitolvanen@google.com
[ Upstream commit 6a03469a1edc94da52b65478f1e00837add869a3 ]
With CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y, we compile the kernel with -fdata-sections, which also splits the .bss section.
The new section, with a new .bss.* name, which pattern gets missed by the main x86 linker script which only expects the '.bss' name. This results in the discarding of the second part and a too small, truncated .bss section and an unhappy, non-working kernel.
Use the common BSS_MAIN macro in the linker script to properly capture and merge all the generated BSS sections.
Signed-off-by: Sami Tolvanen samitolvanen@google.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Kees Cook keescook@chromium.org Cc: Borislav Petkov bp@alien8.de Cc: Kees Cook keescook@chromium.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Nicholas Piggin npiggin@gmail.com Cc: Nick Desaulniers ndesaulniers@google.com Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/20190415164956.124067-1-samitolvanen@google.com [ Extended the changelog. ] Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/vmlinux.lds.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 8d8e33b720b4e..f9f33a168a002 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -352,7 +352,7 @@ SECTIONS .bss : AT(ADDR(.bss) - LOAD_OFFSET) { __bss_start = .; *(.bss..page_aligned) - *(.bss) + *(BSS_MAIN) . = ALIGN(PAGE_SIZE); __bss_stop = .; }