Messages in this thread Patch in this message | | | From | Tom Lendacky <> | Subject | [PATCH] x86/mm/sme: Disable stack protection for mem_encrypt_identity.c | Date | Mon, 26 Feb 2018 17:25:54 -0600 |
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Stack protection is not compatible with early boot code. All of the early SME boot code is now isolated in a separate file, mem_encrypt_identity.c, so arch/x86/mm/Makefile can be updated to turn off stack protection for the entire file. This eliminates the need to worry about other functions within the file being instrumented with stack protection (as was seen when a newer version of GCC instrumented sme_encrypt_kernel() where an older version hadn't). It also allows removal of the __nostackprotector attribute from individual functions.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> --- arch/x86/mm/Makefile | 1 + arch/x86/mm/mem_encrypt_identity.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 03c6c85..4b101dd 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -19,6 +19,7 @@ obj-y := init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \ nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_physaddr.o := $(nostackp) CFLAGS_setup_nx.o := $(nostackp) +CFLAGS_mem_encrypt_identity.o := $(nostackp) CFLAGS_fault.o := -I$(src)/../include/asm/trace diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index b4139c5..1b2197d 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -266,7 +266,7 @@ static unsigned long __init sme_pgtable_calc(unsigned long len) return entries + tables; } -void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp) +void __init sme_encrypt_kernel(struct boot_params *bp) { unsigned long workarea_start, workarea_end, workarea_len; unsigned long execute_start, execute_end, execute_len; @@ -468,7 +468,7 @@ void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp) native_write_cr3(__native_read_cr3()); } -void __init __nostackprotector sme_enable(struct boot_params *bp) +void __init sme_enable(struct boot_params *bp) { const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off; unsigned int eax, ebx, ecx, edx;
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