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

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

diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 401e30c..8272a44 100644 (file)
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -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;

diff --git a/arch/x86/kernel/cpu/mtrr/cyrix.c b/arch/x86/kernel/cpu/mtrr/cyrix.c
index 4296c70..7218280 100644 (file)
--- a/arch/x86/kernel/cpu/mtrr/cyrix.c
+++ b/arch/x86/kernel/cpu/mtrr/cyrix.c
@@ -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:

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 0fdbe89..3c5bbe8 100644 (file)
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -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;

diff --git a/arch/x86/lib/cpu.c b/arch/x86/lib/cpu.c
index 04967cd..7ad6891 100644 (file)
--- a/arch/x86/lib/cpu.c
+++ b/arch/x86/lib/cpu.c
@@ -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)
 {

diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 3cf302b..8901a1f 100644 (file)
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -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)

diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c
index 6d8d5a3..b607bda 100644 (file)
--- a/arch/x86/purgatory/purgatory.c
+++ b/arch/x86/purgatory/purgatory.c
@@ -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) {}

diff --git a/arch/x86/purgatory/string.c b/arch/x86/purgatory/string.c
deleted file mode 100644 (file)
index 01ad438..0000000
--- a/arch/x86/purgatory/string.c
+++ /dev/null
@@ -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);
-}