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
This commit is contained in:
Linus Torvalds 2019-08-10 16:24:03 -07:00
commit 6d8f809cb5
7 changed files with 47 additions and 27 deletions

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@ -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;

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@ -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:

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@ -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;

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@ -1,6 +1,7 @@
// 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)
{

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@ -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.
# 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 += $(CC_FLAGS_FTRACE)
endif
KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large
KBUILD_CFLAGS += -m$(BITS)
KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
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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@ -68,3 +68,9 @@ void purgatory(void)
}
copy_backup_region();
}
/*
* Defined in order to reuse memcpy() and memset() from
* arch/x86/boot/compressed/string.c
*/
void warn(const char *msg) {}

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@ -1,23 +0,0 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Simple string functions.
*
* Copyright (C) 2014 Red Hat Inc.
*
* Author:
* Vivek Goyal <vgoyal@redhat.com>
*/
#include <linux/types.h>
#include "../boot/string.c"
void *memcpy(void *dst, const void *src, size_t len)
{
return __builtin_memcpy(dst, src, len);
}
void *memset(void *dst, int c, size_t len)
{
return __builtin_memset(dst, c, len);
}