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x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()

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In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.

Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:

  On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote:
  >
  > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote:
  > >
  > > However now I see that copy_user_generic() works for the wrong reason.
  > > It works because the exception on the source address due to poison
  > > looks no different than a write fault on the user address to the
  > > caller, it's still just a short copy. So it makes copy_to_user() work
  > > for the wrong reason relative to the name.
  >
  > Right.
  >
  > And it won't work that way on other architectures. On x86, we have a
  > generic function that can take faults on either side, and we use it
  > for both cases (and for the "in_user" case too), but that's an
  > artifact of the architecture oddity.
  >
  > In fact, it's probably wrong even on x86 - because it can hide bugs -
  > but writing those things is painful enough that everybody prefers
  > having just one function.

Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().

Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.

One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.

 [ bp: Massage a bit. ]

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
This commit is contained in:
Dan Williams 2020-10-05 20:40:16 -07:00 committed by Borislav Petkov
parent ed9705e4ad
commit ec6347bb43
38 changed files with 433 additions and 531 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/Kconfig
View File

@ -136,7 +136,7 @@ config PPC
select ARCH_HAS_STRICT_KERNEL_RWX if (PPC32 && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UACCESS_MCSAFE if PPC64
select ARCH_HAS_COPY_MC if PPC64
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK

2
arch/powerpc/include/asm/string.h
View File

@ -53,9 +53,7 @@ void *__memmove(void *to, const void *from, __kernel_size_t n);
#ifndef CONFIG_KASAN
#define __HAVE_ARCH_MEMSET32
#define __HAVE_ARCH_MEMSET64
#define __HAVE_ARCH_MEMCPY_MCSAFE
extern int memcpy_mcsafe(void *dst, const void *src, __kernel_size_t sz);
extern void *__memset16(uint16_t *, uint16_t v, __kernel_size_t);
extern void *__memset32(uint32_t *, uint32_t v, __kernel_size_t);
extern void *__memset64(uint64_t *, uint64_t v, __kernel_size_t);

40
arch/powerpc/include/asm/uaccess.h
View File

@ -435,6 +435,32 @@ do { \
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
#ifdef CONFIG_ARCH_HAS_COPY_MC
unsigned long __must_check
copy_mc_generic(void *to, const void *from, unsigned long size);
static inline unsigned long __must_check
copy_mc_to_kernel(void *to, const void *from, unsigned long size)
{
return copy_mc_generic(to, from, size);
}
#define copy_mc_to_kernel copy_mc_to_kernel
static inline unsigned long __must_check
copy_mc_to_user(void __user *to, const void *from, unsigned long n)
{
if (likely(check_copy_size(from, n, true))) {
if (access_ok(to, n)) {
allow_write_to_user(to, n);
n = copy_mc_generic((void *)to, from, n);
prevent_write_to_user(to, n);
}
}
return n;
}
#endif
#ifdef __powerpc64__
static inline unsigned long
raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
@ -523,20 +549,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
return ret;
}
static __always_inline unsigned long __must_check
copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
{
if (likely(check_copy_size(from, n, true))) {
if (access_ok(to, n)) {
allow_write_to_user(to, n);
n = memcpy_mcsafe((void *)to, from, n);
prevent_write_to_user(to, n);
}
}
return n;
}
unsigned long __arch_clear_user(void __user *addr, unsigned long size);
static inline unsigned long clear_user(void __user *addr, unsigned long size)

2
arch/powerpc/lib/Makefile
View File

@ -39,7 +39,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += copyuser_power7.o copypage_power7.o \
memcpy_power7.o
obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
memcpy_64.o memcpy_mcsafe_64.o
memcpy_64.o copy_mc_64.o
ifndef CONFIG_PPC_QUEUED_SPINLOCKS
obj64-$(CONFIG_SMP) += locks.o

4
arch/powerpc/lib/memcpy_mcsafe_64.S → arch/powerpc/lib/copy_mc_64.S
View File

@ -50,7 +50,7 @@ err3; stb r0,0(r3)
blr
_GLOBAL(memcpy_mcsafe)
_GLOBAL(copy_mc_generic)
mr r7,r5
cmpldi r5,16
blt .Lshort_copy
@ -239,4 +239,4 @@ err1; stb r0,0(r3)
15: li r3,0
blr
EXPORT_SYMBOL_GPL(memcpy_mcsafe);
EXPORT_SYMBOL_GPL(copy_mc_generic);

2
arch/x86/Kconfig
View File

@ -75,7 +75,7 @@ config X86
select ARCH_HAS_PTE_DEVMAP if X86_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_STRICT_KERNEL_RWX

2
arch/x86/Kconfig.debug
View File

@ -62,7 +62,7 @@ config EARLY_PRINTK_USB_XDBC
You should normally say N here, unless you want to debug early
crashes or need a very simple printk logging facility.
config MCSAFE_TEST
config COPY_MC_TEST
def_bool n
config EFI_PGT_DUMP

75
arch/x86/include/asm/copy_mc_test.h Normal file
View File

@ -0,0 +1,75 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _COPY_MC_TEST_H_
#define _COPY_MC_TEST_H_
#ifndef __ASSEMBLY__
#ifdef CONFIG_COPY_MC_TEST
extern unsigned long copy_mc_test_src;
extern unsigned long copy_mc_test_dst;
static inline void copy_mc_inject_src(void *addr)
{
if (addr)
copy_mc_test_src = (unsigned long) addr;
else
copy_mc_test_src = ~0UL;
}
static inline void copy_mc_inject_dst(void *addr)
{
if (addr)
copy_mc_test_dst = (unsigned long) addr;
else
copy_mc_test_dst = ~0UL;
}
#else /* CONFIG_COPY_MC_TEST */
static inline void copy_mc_inject_src(void *addr)
{
}
static inline void copy_mc_inject_dst(void *addr)
{
}
#endif /* CONFIG_COPY_MC_TEST */
#else /* __ASSEMBLY__ */
#include <asm/export.h>
#ifdef CONFIG_COPY_MC_TEST
.macro COPY_MC_TEST_CTL
.pushsection .data
.align 8
.globl copy_mc_test_src
copy_mc_test_src:
.quad 0
EXPORT_SYMBOL_GPL(copy_mc_test_src)
.globl copy_mc_test_dst
copy_mc_test_dst:
.quad 0
EXPORT_SYMBOL_GPL(copy_mc_test_dst)
.popsection
.endm
.macro COPY_MC_TEST_SRC reg count target
leaq \count(\reg), %r9
cmp copy_mc_test_src, %r9
ja \target
.endm
.macro COPY_MC_TEST_DST reg count target
leaq \count(\reg), %r9
cmp copy_mc_test_dst, %r9
ja \target
.endm
#else
.macro COPY_MC_TEST_CTL
.endm
.macro COPY_MC_TEST_SRC reg count target
.endm
.macro COPY_MC_TEST_DST reg count target
.endm
#endif /* CONFIG_COPY_MC_TEST */
#endif /* __ASSEMBLY__ */
#endif /* _COPY_MC_TEST_H_ */

9
arch/x86/include/asm/mce.h
View File

@ -174,6 +174,15 @@ extern void mce_unregister_decode_chain(struct notifier_block *nb);
extern int mce_p5_enabled;
#ifdef CONFIG_ARCH_HAS_COPY_MC
extern void enable_copy_mc_fragile(void);
unsigned long __must_check copy_mc_fragile(void *dst, const void *src, unsigned cnt);
#else
static inline void enable_copy_mc_fragile(void)
{
}
#endif
#ifdef CONFIG_X86_MCE
int mcheck_init(void);
void mcheck_cpu_init(struct cpuinfo_x86 *c);

75
arch/x86/include/asm/mcsafe_test.h
View File

@ -1,75 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MCSAFE_TEST_H_
#define _MCSAFE_TEST_H_
#ifndef __ASSEMBLY__
#ifdef CONFIG_MCSAFE_TEST
extern unsigned long mcsafe_test_src;
extern unsigned long mcsafe_test_dst;
static inline void mcsafe_inject_src(void *addr)
{
if (addr)
mcsafe_test_src = (unsigned long) addr;
else
mcsafe_test_src = ~0UL;
}
static inline void mcsafe_inject_dst(void *addr)
{
if (addr)
mcsafe_test_dst = (unsigned long) addr;
else
mcsafe_test_dst = ~0UL;
}
#else /* CONFIG_MCSAFE_TEST */
static inline void mcsafe_inject_src(void *addr)
{
}
static inline void mcsafe_inject_dst(void *addr)
{
}
#endif /* CONFIG_MCSAFE_TEST */
#else /* __ASSEMBLY__ */
#include <asm/export.h>
#ifdef CONFIG_MCSAFE_TEST
.macro MCSAFE_TEST_CTL
.pushsection .data
.align 8
.globl mcsafe_test_src
mcsafe_test_src:
.quad 0
EXPORT_SYMBOL_GPL(mcsafe_test_src)
.globl mcsafe_test_dst
mcsafe_test_dst:
.quad 0
EXPORT_SYMBOL_GPL(mcsafe_test_dst)
.popsection
.endm
.macro MCSAFE_TEST_SRC reg count target
leaq \count(\reg), %r9
cmp mcsafe_test_src, %r9
ja \target
.endm
.macro MCSAFE_TEST_DST reg count target
leaq \count(\reg), %r9
cmp mcsafe_test_dst, %r9
ja \target
.endm
#else
.macro MCSAFE_TEST_CTL
.endm
.macro MCSAFE_TEST_SRC reg count target
.endm
.macro MCSAFE_TEST_DST reg count target
.endm
#endif /* CONFIG_MCSAFE_TEST */
#endif /* __ASSEMBLY__ */
#endif /* _MCSAFE_TEST_H_ */

32
arch/x86/include/asm/string_64.h
View File

@ -82,38 +82,6 @@ int strcmp(const char *cs, const char *ct);
#endif
#define __HAVE_ARCH_MEMCPY_MCSAFE 1
__must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
size_t cnt);
DECLARE_STATIC_KEY_FALSE(mcsafe_key);
/**
* memcpy_mcsafe - copy memory with indication if a machine check happened
*
* @dst: destination address
* @src: source address
* @cnt: number of bytes to copy
*
* Low level memory copy function that catches machine checks
* We only call into the "safe" function on systems that can
* actually do machine check recovery. Everyone else can just
* use memcpy().
*
* Return 0 for success, or number of bytes not copied if there was an
* exception.
*/
static __always_inline __must_check unsigned long
memcpy_mcsafe(void *dst, const void *src, size_t cnt)
{
#ifdef CONFIG_X86_MCE
if (static_branch_unlikely(&mcsafe_key))
return __memcpy_mcsafe(dst, src, cnt);
else
#endif
memcpy(dst, src, cnt);
return 0;
}
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
void __memcpy_flushcache(void *dst, const void *src, size_t cnt);

9
arch/x86/include/asm/uaccess.h
View File

@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n);
unsigned long __must_check clear_user(void __user *mem, unsigned long len);
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
#ifdef CONFIG_ARCH_HAS_COPY_MC
unsigned long __must_check
copy_mc_to_kernel(void *to, const void *from, unsigned len);
#define copy_mc_to_kernel copy_mc_to_kernel
unsigned long __must_check
copy_mc_to_user(void *to, const void *from, unsigned len);
#endif
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/

20
arch/x86/include/asm/uaccess_64.h
View File

@ -46,22 +46,6 @@ copy_user_generic(void *to, const void *from, unsigned len)
return ret;
}
static __always_inline __must_check unsigned long
copy_to_user_mcsafe(void *to, const void *from, unsigned len)
{
unsigned long ret;
__uaccess_begin();
/*
* Note, __memcpy_mcsafe() is explicitly used since it can
* handle exceptions / faults. memcpy_mcsafe() may fall back to
* memcpy() which lacks this handling.
*/
ret = __memcpy_mcsafe(to, from, len);
__uaccess_end();
return ret;
}
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
@ -102,8 +86,4 @@ __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
kasan_check_write(dst, size);
return __copy_user_flushcache(dst, src, size);
}
unsigned long
mcsafe_handle_tail(char *to, char *from, unsigned len);
#endif /* _ASM_X86_UACCESS_64_H */

8
arch/x86/kernel/cpu/mce/core.c
View File

@ -40,7 +40,6 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
#include <linux/jump_label.h>
#include <linux/set_memory.h>
#include <linux/sync_core.h>
#include <linux/task_work.h>
@ -2124,7 +2123,7 @@ void mce_disable_bank(int bank)
and older.
* mce=nobootlog Don't log MCEs from before booting.
* mce=bios_cmci_threshold Don't program the CMCI threshold
* mce=recovery force enable memcpy_mcsafe()
* mce=recovery force enable copy_mc_fragile()
*/
static int __init mcheck_enable(char *str)
{
@ -2732,13 +2731,10 @@ static void __init mcheck_debugfs_init(void)
static void __init mcheck_debugfs_init(void) { }
#endif
DEFINE_STATIC_KEY_FALSE(mcsafe_key);
EXPORT_SYMBOL_GPL(mcsafe_key);
static int __init mcheck_late_init(void)
{
if (mca_cfg.recovery)
static_branch_inc(&mcsafe_key);
enable_copy_mc_fragile();
mcheck_debugfs_init();

10
arch/x86/kernel/quirks.c
View File

@ -8,6 +8,7 @@
#include <asm/hpet.h>
#include <asm/setup.h>
#include <asm/mce.h>
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
@ -624,10 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev)
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
amd_disable_seq_and_redirect_scrub);
#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
#include <linux/jump_label.h>
#include <asm/string_64.h>
/* Ivy Bridge, Haswell, Broadwell */
static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
{
@ -636,7 +633,7 @@ static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
pci_read_config_dword(pdev, 0x84, &capid0);
if (capid0 & 0x10)
static_branch_inc(&mcsafe_key);
enable_copy_mc_fragile();
}
/* Skylake */
@ -653,7 +650,7 @@ static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
* enabled, so memory machine check recovery is also enabled.
*/
if ((capid0 & 0xc0) == 0xc0 || (capid5 & 0x1e0))
static_branch_inc(&mcsafe_key);
enable_copy_mc_fragile();
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
@ -661,7 +658,6 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
#endif
#endif
bool x86_apple_machine;
EXPORT_SYMBOL(x86_apple_machine);

1
arch/x86/lib/Makefile
View File

@ -44,6 +44,7 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
lib-y := delay.o misc.o cmdline.o cpu.o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o

82
arch/x86/lib/copy_mc.c Normal file
View File

@ -0,0 +1,82 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
#include <linux/jump_label.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/mce.h>
#ifdef CONFIG_X86_MCE
/*
* See COPY_MC_TEST for self-test of the copy_mc_fragile()
* implementation.
*/
static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key);
void enable_copy_mc_fragile(void)
{
static_branch_inc(&copy_mc_fragile_key);
}
#define copy_mc_fragile_enabled (static_branch_unlikely(&copy_mc_fragile_key))
/*
* Similar to copy_user_handle_tail, probe for the write fault point, or
* source exception point.
*/
__visible notrace unsigned long
copy_mc_fragile_handle_tail(char *to, char *from, unsigned len)
{
for (; len; --len, to++, from++)
if (copy_mc_fragile(to, from, 1))
break;
return len;
}
#else
/*
* No point in doing careful copying, or consulting a static key when
* there is no #MC handler in the CONFIG_X86_MCE=n case.
*/
void enable_copy_mc_fragile(void)
{
}
#define copy_mc_fragile_enabled (0)
#endif
/**
* copy_mc_to_kernel - memory copy that handles source exceptions
*
* @dst: destination address
* @src: source address
* @len: number of bytes to copy
*
* Call into the 'fragile' version on systems that have trouble
* actually do machine check recovery. Everyone else can just
* use memcpy().
*
* Return 0 for success, or number of bytes not copied if there was an
* exception.
*/
unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len)
{
if (copy_mc_fragile_enabled)
return copy_mc_fragile(dst, src, len);
memcpy(dst, src, len);
return 0;
}
EXPORT_SYMBOL_GPL(copy_mc_to_kernel);
unsigned long __must_check copy_mc_to_user(void *dst, const void *src, unsigned len)
{
unsigned long ret;
if (!copy_mc_fragile_enabled)
return copy_user_generic(dst, src, len);
__uaccess_begin();
ret = copy_mc_fragile(dst, src, len);
__uaccess_end();
return ret;
}

127
arch/x86/lib/copy_mc_64.S Normal file
View File

@ -0,0 +1,127 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */
#include <linux/linkage.h>
#include <asm/copy_mc_test.h>
#include <asm/export.h>
#include <asm/asm.h>
#ifndef CONFIG_UML
#ifdef CONFIG_X86_MCE
COPY_MC_TEST_CTL
/*
* copy_mc_fragile - copy memory with indication if an exception / fault happened
*
* The 'fragile' version is opted into by platform quirks and takes
* pains to avoid unrecoverable corner cases like 'fast-string'
* instruction sequences, and consuming poison across a cacheline
* boundary. The non-fragile version is equivalent to memcpy()
* regardless of CPU machine-check-recovery capability.
*/
SYM_FUNC_START(copy_mc_fragile)
cmpl $8, %edx
/* Less than 8 bytes? Go to byte copy loop */
jb .L_no_whole_words
/* Check for bad alignment of source */
testl $7, %esi
/* Already aligned */
jz .L_8byte_aligned
/* Copy one byte at a time until source is 8-byte aligned */
movl %esi, %ecx
andl $7, %ecx
subl $8, %ecx
negl %ecx
subl %ecx, %edx
.L_read_leading_bytes:
movb (%rsi), %al
COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes
COPY_MC_TEST_DST %rdi 1 .E_leading_bytes
.L_write_leading_bytes:
movb %al, (%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .L_read_leading_bytes
.L_8byte_aligned:
movl %edx, %ecx
andl $7, %edx
shrl $3, %ecx
jz .L_no_whole_words
.L_read_words:
movq (%rsi), %r8
COPY_MC_TEST_SRC %rsi 8 .E_read_words
COPY_MC_TEST_DST %rdi 8 .E_write_words
.L_write_words:
movq %r8, (%rdi)
addq $8, %rsi
addq $8, %rdi
decl %ecx
jnz .L_read_words
/* Any trailing bytes? */
.L_no_whole_words:
andl %edx, %edx
jz .L_done_memcpy_trap
/* Copy trailing bytes */
movl %edx, %ecx
.L_read_trailing_bytes:
movb (%rsi), %al
COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes
COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes
.L_write_trailing_bytes:
movb %al, (%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .L_read_trailing_bytes
/* Copy successful. Return zero */
.L_done_memcpy_trap:
xorl %eax, %eax
.L_done:
ret
SYM_FUNC_END(copy_mc_fragile)
EXPORT_SYMBOL_GPL(copy_mc_fragile)
.section .fixup, "ax"
/*
* Return number of bytes not copied for any failure. Note that
* there is no "tail" handling since the source buffer is 8-byte
* aligned and poison is cacheline aligned.
*/
.E_read_words:
shll $3, %ecx
.E_leading_bytes:
addl %edx, %ecx
.E_trailing_bytes:
mov %ecx, %eax
jmp .L_done
/*
* For write fault handling, given the destination is unaligned,
* we handle faults on multi-byte writes with a byte-by-byte
* copy up to the write-protected page.
*/
.E_write_words:
shll $3, %ecx
addl %edx, %ecx
movl %ecx, %edx
jmp copy_mc_fragile_handle_tail
.previous
_ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
_ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
_ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
_ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif /* CONFIG_X86_MCE */
#endif /* !CONFIG_UML */

115
arch/x86/lib/memcpy_64.S
View File

@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@ -187,117 +186,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
#ifndef CONFIG_UML
MCSAFE_TEST_CTL
/*
* __memcpy_mcsafe - memory copy with machine check exception handling
* Note that we only catch machine checks when reading the source addresses.
* Writes to target are posted and don't generate machine checks.
*/
SYM_FUNC_START(__memcpy_mcsafe)
cmpl $8, %edx
/* Less than 8 bytes? Go to byte copy loop */
jb .L_no_whole_words
/* Check for bad alignment of source */
testl $7, %esi
/* Already aligned */
jz .L_8byte_aligned
/* Copy one byte at a time until source is 8-byte aligned */
movl %esi, %ecx
andl $7, %ecx
subl $8, %ecx
negl %ecx
subl %ecx, %edx
.L_read_leading_bytes:
movb (%rsi), %al
MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
.L_write_leading_bytes:
movb %al, (%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .L_read_leading_bytes
.L_8byte_aligned:
movl %edx, %ecx
andl $7, %edx
shrl $3, %ecx
jz .L_no_whole_words
.L_read_words:
movq (%rsi), %r8
MCSAFE_TEST_SRC %rsi 8 .E_read_words
MCSAFE_TEST_DST %rdi 8 .E_write_words
.L_write_words:
movq %r8, (%rdi)
addq $8, %rsi
addq $8, %rdi
decl %ecx
jnz .L_read_words
/* Any trailing bytes? */
.L_no_whole_words:
andl %edx, %edx
jz .L_done_memcpy_trap
/* Copy trailing bytes */
movl %edx, %ecx
.L_read_trailing_bytes:
movb (%rsi), %al
MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
.L_write_trailing_bytes:
movb %al, (%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .L_read_trailing_bytes
/* Copy successful. Return zero */
.L_done_memcpy_trap:
xorl %eax, %eax
.L_done:
ret
SYM_FUNC_END(__memcpy_mcsafe)
EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
.section .fixup, "ax"
/*
* Return number of bytes not copied for any failure. Note that
* there is no "tail" handling since the source buffer is 8-byte
* aligned and poison is cacheline aligned.
*/
.E_read_words:
shll $3, %ecx
.E_leading_bytes:
addl %edx, %ecx
.E_trailing_bytes:
mov %ecx, %eax
jmp .L_done
/*
* For write fault handling, given the destination is unaligned,
* we handle faults on multi-byte writes with a byte-by-byte
* copy up to the write-protected page.
*/
.E_write_words:
shll $3, %ecx
addl %edx, %ecx
movl %ecx, %edx
jmp mcsafe_handle_tail
.previous
_ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
_ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
_ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
_ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif

21
arch/x86/lib/usercopy_64.c
View File

@ -56,27 +56,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
}
EXPORT_SYMBOL(clear_user);
/*
* Similar to copy_user_handle_tail, probe for the write fault point,
* but reuse __memcpy_mcsafe in case a new read error is encountered.
* clac() is handled in _copy_to_iter_mcsafe().
*/
__visible notrace unsigned long
mcsafe_handle_tail(char *to, char *from, unsigned len)
{
for (; len; --len, to++, from++) {
/*
* Call the assembly routine back directly since
* memcpy_mcsafe() may silently fallback to memcpy.
*/
unsigned long rem = __memcpy_mcsafe(to, from, 1);
if (rem)
break;
}
return len;
}
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
/**
* clean_cache_range - write back a cache range with CLWB

15
drivers/md/dm-writecache.c
View File

@ -49,7 +49,7 @@ do { \
#define pmem_assign(dest, src) ((dest) = (src))
#endif
#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM)
#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM)
#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
#endif
@ -984,7 +984,8 @@ static void writecache_resume(struct dm_target *ti)
}
wc->freelist_size = 0;
r = memcpy_mcsafe(&sb_seq_count, &sb(wc)->seq_count, sizeof(uint64_t));
r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count,
sizeof(uint64_t));
if (r) {
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r);
sb_seq_count = cpu_to_le64(0);
@ -1000,7 +1001,8 @@ static void writecache_resume(struct dm_target *ti)
e->seq_count = -1;
continue;
}
r = memcpy_mcsafe(&wme, memory_entry(wc, e), sizeof(struct wc_memory_entry));
r = copy_mc_to_kernel(&wme, memory_entry(wc, e),
sizeof(struct wc_memory_entry));
if (r) {
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d",
(unsigned long)b, r);
@ -1198,7 +1200,7 @@ static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data
if (rw == READ) {
int r;
r = memcpy_mcsafe(buf, data, size);
r = copy_mc_to_kernel(buf, data, size);
flush_dcache_page(bio_page(bio));
if (unlikely(r)) {
writecache_error(wc, r, "hardware memory error when reading data: %d", r);
@ -2341,7 +2343,7 @@ invalid_optional:
}
}
r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
@ -2352,7 +2354,8 @@ invalid_optional:
ti->error = "Unable to initialize device";
goto bad;
}
r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock));
r = copy_mc_to_kernel(&s, sb(wc),
sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;

2
drivers/nvdimm/claim.c
View File

@ -268,7 +268,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
if (rw == READ) {
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
return -EIO;
if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
return -EIO;
return 0;
}

6
drivers/nvdimm/pmem.c
View File

@ -125,7 +125,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE - off);
rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
kunmap_atomic(mem);
if (rem)
return BLK_STS_IOERR;
@ -304,7 +304,7 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
/*
* Use the 'no check' versions of copy_from_iter_flushcache() and
* copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
* copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
* checking, both file offset and device offset, is handled by
* dax_iomap_actor()
*/
@ -317,7 +317,7 @@ static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
return _copy_to_iter_mcsafe(addr, bytes, i);
return _copy_mc_to_iter(addr, bytes, i);
}
static const struct dax_operations pmem_dax_ops = {

9
include/linux/string.h
View File

@ -161,20 +161,13 @@ extern int bcmp(const void *,const void *,__kernel_size_t);
#ifndef __HAVE_ARCH_MEMCHR
extern void * memchr(const void *,int,__kernel_size_t);
#endif
#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
static inline __must_check unsigned long memcpy_mcsafe(void *dst,
const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
return 0;
}
#endif
#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
}
#endif
void *memchr_inv(const void *s, int c, size_t n);
char *strreplace(char *s, char old, char new);

13
include/linux/uaccess.h
View File

@ -179,6 +179,19 @@ copy_in_user(void __user *to, const void __user *from, unsigned long n)
}
#endif
#ifndef copy_mc_to_kernel
/*
* Without arch opt-in this generic copy_mc_to_kernel() will not handle
* #MC (or arch equivalent) during source read.
*/
static inline unsigned long __must_check
copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
{
memcpy(dst, src, cnt);
return 0;
}
#endif
static __always_inline void pagefault_disabled_inc(void)
{
current->pagefault_disabled++;

10
include/linux/uio.h
View File

@ -185,10 +185,10 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
#define _copy_from_iter_flushcache _copy_from_iter_nocache
#endif
#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i);
#ifdef CONFIG_ARCH_HAS_COPY_MC
size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
#else
#define _copy_to_iter_mcsafe _copy_to_iter
#define _copy_mc_to_iter _copy_to_iter
#endif
static __always_inline __must_check
@ -201,12 +201,12 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
}
static __always_inline __must_check
size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
if (unlikely(!check_copy_size(addr, bytes, true)))
return 0;
else
return _copy_to_iter_mcsafe(addr, bytes, i);
return _copy_mc_to_iter(addr, bytes, i);
}
size_t iov_iter_zero(size_t bytes, struct iov_iter *);

7
lib/Kconfig
View File

@ -635,7 +635,12 @@ config UACCESS_MEMCPY
config ARCH_HAS_UACCESS_FLUSHCACHE
bool
config ARCH_HAS_UACCESS_MCSAFE
# arch has a concept of a recoverable synchronous exception due to a
# memory-read error like x86 machine-check or ARM data-abort, and
# implements copy_mc_to_{user,kernel} to abort and report
# 'bytes-transferred' if that exception fires when accessing the source
# buffer.
config ARCH_HAS_COPY_MC
bool
# Temporary. Goes away when all archs are cleaned up

48
lib/iov_iter.c
View File

@ -637,30 +637,30 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(_copy_to_iter);
#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
static int copyout_mcsafe(void __user *to, const void *from, size_t n)
#ifdef CONFIG_ARCH_HAS_COPY_MC
static int copyout_mc(void __user *to, const void *from, size_t n)
{
if (access_ok(to, n)) {
instrument_copy_to_user(to, from, n);
n = copy_to_user_mcsafe((__force void *) to, from, n);
n = copy_mc_to_user((__force void *) to, from, n);
}
return n;
}
static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
static unsigned long copy_mc_to_page(struct page *page, size_t offset,
const char *from, size_t len)
{
unsigned long ret;
char *to;
to = kmap_atomic(page);
ret = memcpy_mcsafe(to + offset, from, len);
ret = copy_mc_to_kernel(to + offset, from, len);
kunmap_atomic(to);
return ret;
}
static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct iov_iter *i)
{
struct pipe_inode_info *pipe = i->pipe;
@ -678,7 +678,7 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
unsigned long rem;
rem = memcpy_mcsafe_to_page(pipe->bufs[i_head & p_mask].page,
rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page,
off, addr, chunk);
i->head = i_head;
i->iov_offset = off + chunk - rem;
@ -695,18 +695,17 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
}
/**
* _copy_to_iter_mcsafe - copy to user with source-read error exception handling
* _copy_mc_to_iter - copy to iter with source memory error exception handling
* @addr: source kernel address
* @bytes: total transfer length
* @iter: destination iterator
*
* The pmem driver arranges for filesystem-dax to use this facility via
* dax_copy_to_iter() for protecting read/write to persistent memory.
* Unless / until an architecture can guarantee identical performance
* between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a
* performance regression to switch more users to the mcsafe version.
* The pmem driver deploys this for the dax operation
* (dax_copy_to_iter()) for dax reads (bypass page-cache and the
* block-layer). Upon #MC read(2) aborts and returns EIO or the bytes
* successfully copied.
*
* Otherwise, the main differences between this and typical _copy_to_iter().
* The main differences between this and typical _copy_to_iter().
*
* * Typical tail/residue handling after a fault retries the copy
* byte-by-byte until the fault happens again. Re-triggering machine
@ -717,23 +716,22 @@ static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
* * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
* Compare to copy_to_iter() where only ITER_IOVEC attempts might return
* a short copy.
*
* See MCSAFE_TEST for self-test.
*/
size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
if (unlikely(iov_iter_is_pipe(i)))
return copy_pipe_to_iter_mcsafe(addr, bytes, i);
return copy_mc_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
iterate_and_advance(i, bytes, v,
copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len,
v.iov_len),
({
rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
(from += v.bv_len) - v.bv_len, v.bv_len);
rem = copy_mc_to_page(v.bv_page, v.bv_offset,
(from += v.bv_len) - v.bv_len, v.bv_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@ -741,8 +739,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
}
}),
({
rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len,
v.iov_len);
rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len)
- v.iov_len, v.iov_len);
if (rem) {
curr_addr = (unsigned long) from;
bytes = curr_addr - s_addr - rem;
@ -753,8 +751,8 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */
EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
#endif /* CONFIG_ARCH_HAS_COPY_MC */
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{

13
tools/arch/x86/include/asm/mcsafe_test.h
View File

@ -1,13 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MCSAFE_TEST_H_
#define _MCSAFE_TEST_H_
.macro MCSAFE_TEST_CTL
.endm
.macro MCSAFE_TEST_SRC reg count target
.endm
.macro MCSAFE_TEST_DST reg count target
.endm
#endif /* _MCSAFE_TEST_H_ */

115
tools/arch/x86/lib/memcpy_64.S
View File

@ -4,7 +4,6 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
#include <asm/mcsafe_test.h>
#include <asm/alternative-asm.h>
#include <asm/export.h>
@ -187,117 +186,3 @@ SYM_FUNC_START(memcpy_orig)
SYM_FUNC_END(memcpy_orig)
.popsection
#ifndef CONFIG_UML
MCSAFE_TEST_CTL
/*
* __memcpy_mcsafe - memory copy with machine check exception handling
* Note that we only catch machine checks when reading the source addresses.
* Writes to target are posted and don't generate machine checks.
*/
SYM_FUNC_START(__memcpy_mcsafe)
cmpl $8, %edx
/* Less than 8 bytes? Go to byte copy loop */
jb .L_no_whole_words
/* Check for bad alignment of source */
testl $7, %esi
/* Already aligned */
jz .L_8byte_aligned
/* Copy one byte at a time until source is 8-byte aligned */
movl %esi, %ecx
andl $7, %ecx
subl $8, %ecx
negl %ecx
subl %ecx, %edx
.L_read_leading_bytes:
movb (%rsi), %al
MCSAFE_TEST_SRC %rsi 1 .E_leading_bytes
MCSAFE_TEST_DST %rdi 1 .E_leading_bytes
.L_write_leading_bytes:
movb %al, (%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .L_read_leading_bytes
.L_8byte_aligned:
movl %edx, %ecx
andl $7, %edx
shrl $3, %ecx
jz .L_no_whole_words
.L_read_words:
movq (%rsi), %r8
MCSAFE_TEST_SRC %rsi 8 .E_read_words
MCSAFE_TEST_DST %rdi 8 .E_write_words
.L_write_words:
movq %r8, (%rdi)
addq $8, %rsi
addq $8, %rdi
decl %ecx
jnz .L_read_words
/* Any trailing bytes? */
.L_no_whole_words:
andl %edx, %edx
jz .L_done_memcpy_trap
/* Copy trailing bytes */
movl %edx, %ecx
.L_read_trailing_bytes:
movb (%rsi), %al
MCSAFE_TEST_SRC %rsi 1 .E_trailing_bytes
MCSAFE_TEST_DST %rdi 1 .E_trailing_bytes
.L_write_trailing_bytes:
movb %al, (%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz .L_read_trailing_bytes
/* Copy successful. Return zero */
.L_done_memcpy_trap:
xorl %eax, %eax
.L_done:
ret
SYM_FUNC_END(__memcpy_mcsafe)
EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
.section .fixup, "ax"
/*
* Return number of bytes not copied for any failure. Note that
* there is no "tail" handling since the source buffer is 8-byte
* aligned and poison is cacheline aligned.
*/
.E_read_words:
shll $3, %ecx
.E_leading_bytes:
addl %edx, %ecx
.E_trailing_bytes:
mov %ecx, %eax
jmp .L_done
/*
* For write fault handling, given the destination is unaligned,
* we handle faults on multi-byte writes with a byte-by-byte
* copy up to the write-protected page.
*/
.E_write_words:
shll $3, %ecx
addl %edx, %ecx
movl %ecx, %edx
jmp mcsafe_handle_tail
.previous
_ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
_ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
_ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
_ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
_ASM_EXTABLE(.L_write_words, .E_write_words)
_ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif

4
tools/objtool/check.c
View File

@ -548,8 +548,8 @@ static const char *uaccess_safe_builtin[] = {
"__ubsan_handle_shift_out_of_bounds",
/* misc */
"csum_partial_copy_generic",
"__memcpy_mcsafe",
"mcsafe_handle_tail",
"copy_mc_fragile",
"copy_mc_fragile_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};

1
tools/perf/bench/Build
View File

@ -13,7 +13,6 @@ perf-y += synthesize.o
perf-y += kallsyms-parse.o
perf-y += find-bit-bench.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o

24
tools/perf/bench/mem-memcpy-x86-64-lib.c
View File

@ -1,24 +0,0 @@
/*
* From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
* of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
* happy.
*/
#include <linux/types.h>
unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
{
for (; len; --len, to++, from++) {
/*
* Call the assembly routine back directly since
* memcpy_mcsafe() may silently fallback to memcpy.
*/
unsigned long rem = __memcpy_mcsafe(to, from, 1);
if (rem)
break;
}
return len;
}

49
tools/testing/nvdimm/test/nfit.c
View File

@ -23,7 +23,8 @@
#include "nfit_test.h"
#include "../watermark.h"
#include <asm/mcsafe_test.h>
#include <asm/copy_mc_test.h>
#include <asm/mce.h>
/*
* Generate an NFIT table to describe the following topology:
@ -3283,7 +3284,7 @@ static struct platform_driver nfit_test_driver = {
.id_table = nfit_test_id,
};
static char mcsafe_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
static char copy_mc_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
enum INJECT {
INJECT_NONE,
@ -3291,7 +3292,7 @@ enum INJECT {
INJECT_DST,
};
static void mcsafe_test_init(char *dst, char *src, size_t size)
static void copy_mc_test_init(char *dst, char *src, size_t size)
{
size_t i;
@ -3300,7 +3301,7 @@ static void mcsafe_test_init(char *dst, char *src, size_t size)
src[i] = (char) i;
}
static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
static bool copy_mc_test_validate(unsigned char *dst, unsigned char *src,
size_t size, unsigned long rem)
{
size_t i;
@ -3321,12 +3322,12 @@ static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src,
return true;
}
void mcsafe_test(void)
void copy_mc_test(void)
{
char *inject_desc[] = { "none", "source", "destination" };
enum INJECT inj;
if (IS_ENABLED(CONFIG_MCSAFE_TEST)) {
if (IS_ENABLED(CONFIG_COPY_MC_TEST)) {
pr_info("%s: run...\n", __func__);
} else {
pr_info("%s: disabled, skip.\n", __func__);
@ -3344,31 +3345,31 @@ void mcsafe_test(void)
switch (inj) {
case INJECT_NONE:
mcsafe_inject_src(NULL);
mcsafe_inject_dst(NULL);
dst = &mcsafe_buf[2048];
src = &mcsafe_buf[1024 - i];
copy_mc_inject_src(NULL);
copy_mc_inject_dst(NULL);
dst = &copy_mc_buf[2048];
src = &copy_mc_buf[1024 - i];
expect = 0;
break;
case INJECT_SRC:
mcsafe_inject_src(&mcsafe_buf[1024]);
mcsafe_inject_dst(NULL);
dst = &mcsafe_buf[2048];
src = &mcsafe_buf[1024 - i];
copy_mc_inject_src(&copy_mc_buf[1024]);
copy_mc_inject_dst(NULL);
dst = &copy_mc_buf[2048];
src = &copy_mc_buf[1024 - i];
expect = 512 - i;
break;
case INJECT_DST:
mcsafe_inject_src(NULL);
mcsafe_inject_dst(&mcsafe_buf[2048]);
dst = &mcsafe_buf[2048 - i];
src = &mcsafe_buf[1024];
copy_mc_inject_src(NULL);
copy_mc_inject_dst(&copy_mc_buf[2048]);
dst = &copy_mc_buf[2048 - i];
src = &copy_mc_buf[1024];
expect = 512 - i;
break;
}
mcsafe_test_init(dst, src, 512);
rem = __memcpy_mcsafe(dst, src, 512);
valid = mcsafe_test_validate(dst, src, 512, expect);
copy_mc_test_init(dst, src, 512);
rem = copy_mc_fragile(dst, src, 512);
valid = copy_mc_test_validate(dst, src, 512, expect);
if (rem == expect && valid)
continue;
pr_info("%s: copy(%#lx, %#lx, %d) off: %d rem: %ld %s expect: %ld\n",
@ -3380,8 +3381,8 @@ void mcsafe_test(void)
}
}
mcsafe_inject_src(NULL);
mcsafe_inject_dst(NULL);
copy_mc_inject_src(NULL);
copy_mc_inject_dst(NULL);
}
static __init int nfit_test_init(void)
@ -3392,7 +3393,7 @@ static __init int nfit_test_init(void)
libnvdimm_test();
acpi_nfit_test();
device_dax_test();
mcsafe_test();
copy_mc_test();
dax_pmem_test();
dax_pmem_core_test();
#ifdef CONFIG_DEV_DAX_PMEM_COMPAT

2
tools/testing/selftests/powerpc/copyloops/.gitignore vendored
View File

@ -12,4 +12,4 @@ memcpy_p7_t1
copyuser_64_exc_t0
copyuser_64_exc_t1
copyuser_64_exc_t2
memcpy_mcsafe_64
copy_mc_64

6
tools/testing/selftests/powerpc/copyloops/Makefile
View File

@ -12,7 +12,7 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4
TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \
copyuser_p7_t0 copyuser_p7_t1 \
memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
memcpy_p7_t0 memcpy_p7_t1 memcpy_mcsafe_64 \
memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2
EXTRA_SOURCES := validate.c ../harness.c stubs.S
@ -45,9 +45,9 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \
-o $@ $^
$(OUTPUT)/memcpy_mcsafe_64: memcpy_mcsafe_64.S $(EXTRA_SOURCES)
$(OUTPUT)/copy_mc_64: copy_mc_64.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
-D COPY_LOOP=test_memcpy_mcsafe \
-D COPY_LOOP=test_copy_mc_generic \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \

1
tools/testing/selftests/powerpc/copyloops/copy_mc_64.S Symbolic link
View File

@ -0,0 +1 @@
../../../../../arch/powerpc/lib/copy_mc_64.S

1
tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
View File

@ -1 +0,0 @@
../../../../../arch/powerpc/lib/memcpy_mcsafe_64.S