Commit 6d8f809c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Thomas Gleixner:
 "A few fixes for x86:

   - Don't reset the carefully adjusted build flags for the purgatory
     and remove the unwanted flags instead. The 'reset all' approach led
     to build fails under certain circumstances.

   - Unbreak CLANG build of the purgatory by avoiding the builtin
     memcpy/memset implementations.

   - Address missing prototype warnings by including the proper header

   - Fix yet more fall-through issues"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/lib/cpu: Address missing prototypes warning
  x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
  x86/purgatory: Do not use __builtin_memcpy and __builtin_memset
  x86: mtrr: cyrix: Mark expected switch fall-through
  x86/ptrace: Mark expected switch fall-through
parents d2359a51 04f5bda8

arch/x86/boot/string.c

+8 −0
Original line number Diff line number Diff line
@@ -37,6 +37,14 @@ int memcmp(const void *s1, const void *s2, size_t len) 
	return diff;

}



/*

 * Clang may lower `memcmp == 0` to `bcmp == 0`.

 */

int bcmp(const void *s1, const void *s2, size_t len)

{

	return memcmp(s1, s2, len);

}



int strcmp(const char *str1, const char *str2)

{

	const unsigned char *s1 = (const unsigned char *)str1;

arch/x86/kernel/cpu/mtrr/cyrix.c

+1 −0
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ cyrix_get_free_region(unsigned long base, unsigned long size, int replace_reg) 
	case 7:

		if (size < 0x40)

			break;

		/* Else, fall through */

	case 6:

	case 5:

	case 4:

arch/x86/kernel/ptrace.c

+1 −0
Original line number Diff line number Diff line
@@ -201,6 +201,7 @@ static int set_segment_reg(struct task_struct *task, 
	case offsetof(struct user_regs_struct, ss):

		if (unlikely(value == 0))

			return -EIO;

		/* Else, fall through */



	default:

		*pt_regs_access(task_pt_regs(task), offset) = value;

arch/x86/lib/cpu.c

+1 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/types.h>

#include <linux/export.h>

#include <asm/cpu.h>



unsigned int x86_family(unsigned int sig)

{

arch/x86/purgatory/Makefile

+31 −5
Original line number Diff line number Diff line
@@ -6,6 +6,9 @@ purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string 
targets += $(purgatory-y)

PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))



$(obj)/string.o: $(srctree)/arch/x86/boot/compressed/string.c FORCE

	$(call if_changed_rule,cc_o_c)



$(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE

	$(call if_changed_rule,cc_o_c)
@@ -17,11 +20,34 @@ KCOV_INSTRUMENT := n 


# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That

# in turn leaves some undefined symbols like __fentry__ in purgatory and not

# sure how to relocate those. Like kexec-tools, use custom flags.



KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large

KBUILD_CFLAGS += -m$(BITS)

KBUILD_CFLAGS += $(call cc-option,-fno-PIE)

# sure how to relocate those.

ifdef CONFIG_FUNCTION_TRACER

CFLAGS_REMOVE_sha256.o		+= $(CC_FLAGS_FTRACE)

CFLAGS_REMOVE_purgatory.o	+= $(CC_FLAGS_FTRACE)

CFLAGS_REMOVE_string.o		+= $(CC_FLAGS_FTRACE)

CFLAGS_REMOVE_kexec-purgatory.o	+= $(CC_FLAGS_FTRACE)

endif



ifdef CONFIG_STACKPROTECTOR

CFLAGS_REMOVE_sha256.o		+= -fstack-protector

CFLAGS_REMOVE_purgatory.o	+= -fstack-protector

CFLAGS_REMOVE_string.o		+= -fstack-protector

CFLAGS_REMOVE_kexec-purgatory.o	+= -fstack-protector

endif



ifdef CONFIG_STACKPROTECTOR_STRONG

CFLAGS_REMOVE_sha256.o		+= -fstack-protector-strong

CFLAGS_REMOVE_purgatory.o	+= -fstack-protector-strong

CFLAGS_REMOVE_string.o		+= -fstack-protector-strong

CFLAGS_REMOVE_kexec-purgatory.o	+= -fstack-protector-strong

endif



ifdef CONFIG_RETPOLINE

CFLAGS_REMOVE_sha256.o		+= $(RETPOLINE_CFLAGS)

CFLAGS_REMOVE_purgatory.o	+= $(RETPOLINE_CFLAGS)

CFLAGS_REMOVE_string.o		+= $(RETPOLINE_CFLAGS)

CFLAGS_REMOVE_kexec-purgatory.o	+= $(RETPOLINE_CFLAGS)

endif



$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE

		$(call if_changed,ld)

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