From: Sami Tolvanen <samitolvanen@xxxxxxxxxx> [ 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@xxxxxxxxxx> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20190415164956.124067-1-samitolvanen@xxxxxxxxxx [ Extended the changelog. ] Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 097268f85e4ee..0df44e4fe7cb1 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -329,7 +329,7 @@ SECTIONS .bss : AT(ADDR(.bss) - LOAD_OFFSET) { __bss_start = .; *(.bss..page_aligned) - *(.bss) + *(BSS_MAIN) . = ALIGN(PAGE_SIZE); __bss_stop = .; } -- 2.25.1
