From: Tom Lendacky Date: Mon, 26 Feb 2018 23:25:54 +0000 (-0600) Subject: x86/mm/sme: Disable stack protection for mem_encrypt_identity.c X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ae8d1d0061ad7996c2c5e769e809a593544fa145;p=linux.git x86/mm/sme: Disable stack protection for mem_encrypt_identity.c 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 Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Acked-by: Kirill A. Shutemov Cc: Linus Torvalds Cc: Borislav Petkov Link: https://lkml.kernel.org/r/20180226232554.14108.16881.stgit@tlendack-t1.amdoffice.net --- diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 03c6c8561623d..4b101dd6e52f3 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 b4139c5ab972f..1b2197d13832e 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;