The following commit has been merged into the x86/urgent branch of tip: Commit-ID: aef0148f3606117352053c015cb33734e9ee7397 Gitweb: https://git.kernel.org/tip/aef0148f3606117352053c015cb33734e9ee7397 Author: Arvind Sankar <nivedita@xxxxxxxxxxxx> AuthorDate: Wed, 02 Sep 2020 22:30:56 -04:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Thu, 03 Sep 2020 10:59:16 +02:00 x86/cmdline: Disable jump tables for cmdline.c When CONFIG_RETPOLINE is disabled, Clang uses a jump table for the switch statement in cmdline_find_option (jump tables are disabled when CONFIG_RETPOLINE is enabled). This function is called very early in boot from sme_enable() if CONFIG_AMD_MEM_ENCRYPT is enabled. At this time, the kernel is still executing out of the identity mapping, but the jump table will contain virtual addresses. Fix this by disabling jump tables for cmdline.c when AMD_MEM_ENCRYPT is enabled. Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200903023056.3914690-1-nivedita@xxxxxxxxxxxx --- arch/x86/lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index d46fff1..aa06785 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -24,7 +24,7 @@ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_cmdline.o = -pg endif -CFLAGS_cmdline.o := -fno-stack-protector +CFLAGS_cmdline.o := -fno-stack-protector -fno-jump-tables endif inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk
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