| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 30 Jul 2018 17:50:30 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Ingo Molnar <mingo@...nel.org>
Cc: Clark Williams <williams@...hat.com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org,
Arnaldo Carvalho de Melo <acme@...hat.com>,
Adrian Hunter <adrian.hunter@...el.com>,
Dan Williams <dan.j.williams@...el.com>,
David Ahern <dsahern@...il.com>, Jiri Olsa <jolsa@...nel.org>,
Mika Penttilä <mika.penttila@...tfour.com>,
Namhyung Kim <namhyung@...nel.org>,
Tony Luck <tony.luck@...el.com>, Wang Nan <wangnan0@...wei.com>
Subject: [PATCH 4/5] tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'
From: Arnaldo Carvalho de Melo <acme@...hat.com>
To cope with the changes in:
12c89130a56a ("x86/asm/memcpy_mcsafe: Add write-protection-fault handling")
60622d68227d ("x86/asm/memcpy_mcsafe: Return bytes remaining")
bd131544aa7e ("x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling")
da7bc9c57eb0 ("x86/asm/memcpy_mcsafe: Remove loop unrolling")
This needed introducing a file with a copy of the mcsafe_handle_tail()
function, that is used in the new memcpy_64.S file, as well as a dummy
mcsafe_test.h header.
Testing it:
$ nm ~/bin/perf | grep mcsafe
0000000000484130 T mcsafe_handle_tail
0000000000484300 T __memcpy_mcsafe
$
$ perf bench mem memcpy
# Running 'mem/memcpy' benchmark:
# function 'default' (Default memcpy() provided by glibc)
# Copying 1MB bytes ...
44.389205 GB/sec
# function 'x86-64-unrolled' (unrolled memcpy() in arch/x86/lib/memcpy_64.S)
# Copying 1MB bytes ...
22.710756 GB/sec
# function 'x86-64-movsq' (movsq-based memcpy() in arch/x86/lib/memcpy_64.S)
# Copying 1MB bytes ...
42.459239 GB/sec
# function 'x86-64-movsb' (movsb-based memcpy() in arch/x86/lib/memcpy_64.S)
# Copying 1MB bytes ...
42.459239 GB/sec
$
This silences this perf tools build warning:
Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
Cc: Adrian Hunter <adrian.hunter@...el.com>
Cc: Dan Williams <dan.j.williams@...el.com>
Cc: David Ahern <dsahern@...il.com>
Cc: Jiri Olsa <jolsa@...nel.org>
Cc: Mika Penttilä <mika.penttila@...tfour.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Tony Luck <tony.luck@...el.com>
Cc: Wang Nan <wangnan0@...wei.com>
Link: https://lkml.kernel.org/n/tip-igdpciheradk3gb3qqal52d0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
tools/arch/x86/include/asm/mcsafe_test.h | 13 ++++
tools/arch/x86/lib/memcpy_64.S | 112 +++++++++++++++----------------
tools/perf/bench/Build | 1 +
tools/perf/bench/mem-memcpy-x86-64-asm.S | 1 +
tools/perf/bench/mem-memcpy-x86-64-lib.c | 24 +++++++
5 files changed, 93 insertions(+), 58 deletions(-)
create mode 100644 tools/arch/x86/include/asm/mcsafe_test.h
create mode 100644 tools/perf/bench/mem-memcpy-x86-64-lib.c
diff --git a/tools/arch/x86/include/asm/mcsafe_test.h b/tools/arch/x86/include/asm/mcsafe_test.h
new file mode 100644
index 000000000000..2ccd588fbad4
--- /dev/null
+++ b/tools/arch/x86/include/asm/mcsafe_test.h
@@ -0,0 +1,13 @@
+/* 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_ */
diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 9a53a06e5a3e..298ef1479240 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -3,6 +3,7 @@
#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>
@@ -183,12 +184,15 @@ ENTRY(memcpy_orig)
ENDPROC(memcpy_orig)
#ifndef CONFIG_UML
+
+MCSAFE_TEST_CTL
+
/*
- * memcpy_mcsafe_unrolled - memory copy with machine check exception handling
+ * __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.
*/
-ENTRY(memcpy_mcsafe_unrolled)
+ENTRY(__memcpy_mcsafe)
cmpl $8, %edx
/* Less than 8 bytes? Go to byte copy loop */
jb .L_no_whole_words
@@ -204,58 +208,33 @@ ENTRY(memcpy_mcsafe_unrolled)
subl $8, %ecx
negl %ecx
subl %ecx, %edx
-.L_copy_leading_bytes:
+.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_copy_leading_bytes
+ jnz .L_read_leading_bytes
.L_8byte_aligned:
- /* Figure out how many whole cache lines (64-bytes) to copy */
- movl %edx, %ecx
- andl $63, %edx
- shrl $6, %ecx
- jz .L_no_whole_cache_lines
-
- /* Loop copying whole cache lines */
-.L_cache_w0: movq (%rsi), %r8
-.L_cache_w1: movq 1*8(%rsi), %r9
-.L_cache_w2: movq 2*8(%rsi), %r10
-.L_cache_w3: movq 3*8(%rsi), %r11
- movq %r8, (%rdi)
- movq %r9, 1*8(%rdi)
- movq %r10, 2*8(%rdi)
- movq %r11, 3*8(%rdi)
-.L_cache_w4: movq 4*8(%rsi), %r8
-.L_cache_w5: movq 5*8(%rsi), %r9
-.L_cache_w6: movq 6*8(%rsi), %r10
-.L_cache_w7: movq 7*8(%rsi), %r11
- movq %r8, 4*8(%rdi)
- movq %r9, 5*8(%rdi)
- movq %r10, 6*8(%rdi)
- movq %r11, 7*8(%rdi)
- leaq 64(%rsi), %rsi
- leaq 64(%rdi), %rdi
- decl %ecx
- jnz .L_cache_w0
-
- /* Are there any trailing 8-byte words? */
-.L_no_whole_cache_lines:
movl %edx, %ecx
andl $7, %edx
shrl $3, %ecx
jz .L_no_whole_words
- /* Copy trailing words */
-.L_copy_trailing_words:
+.L_read_words:
movq (%rsi), %r8
- mov %r8, (%rdi)
- leaq 8(%rsi), %rsi
- leaq 8(%rdi), %rdi
+ 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_copy_trailing_words
+ jnz .L_read_words
/* Any trailing bytes? */
.L_no_whole_words:
@@ -264,38 +243,55 @@ ENTRY(memcpy_mcsafe_unrolled)
/* Copy trailing bytes */
movl %edx, %ecx
-.L_copy_trailing_bytes:
+.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_copy_trailing_bytes
+ jnz .L_read_trailing_bytes
/* Copy successful. Return zero */
.L_done_memcpy_trap:
xorq %rax, %rax
ret
-ENDPROC(memcpy_mcsafe_unrolled)
-EXPORT_SYMBOL_GPL(memcpy_mcsafe_unrolled)
+ENDPROC(__memcpy_mcsafe)
+EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
.section .fixup, "ax"
- /* Return -EFAULT for any failure */
-.L_memcpy_mcsafe_fail:
- mov $-EFAULT, %rax
+ /*
+ * 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
ret
+ /*
+ * 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 $3, %ecx
+ addl %edx, %ecx
+ movl %ecx, %edx
+ jmp mcsafe_handle_tail
+
.previous
- _ASM_EXTABLE_FAULT(.L_copy_leading_bytes, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w0, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w1, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w2, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w3, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w4, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w5, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w6, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_cache_w7, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_copy_trailing_words, .L_memcpy_mcsafe_fail)
- _ASM_EXTABLE_FAULT(.L_copy_trailing_bytes, .L_memcpy_mcsafe_fail)
+ _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE_FAULT(.L_read_words, .E_read_words)
+ _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .E_trailing_bytes)
+ _ASM_EXTABLE(.L_write_leading_bytes, .E_leading_bytes)
+ _ASM_EXTABLE(.L_write_words, .E_write_words)
+ _ASM_EXTABLE(.L_write_trailing_bytes, .E_trailing_bytes)
#endif
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index 60bf11943047..eafce1a130a1 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -7,6 +7,7 @@ perf-y += futex-wake-parallel.o
perf-y += futex-requeue.o
perf-y += futex-lock-pi.o
+perf-$(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
diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S
index b43f8d2a34ec..9ad015a1e202 100644
--- a/tools/perf/bench/mem-memcpy-x86-64-asm.S
+++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S
@@ -6,6 +6,7 @@
#define altinstr_replacement text
#define globl p2align 4; .globl
#define _ASM_EXTABLE_FAULT(x, y)
+#define _ASM_EXTABLE(x, y)
#include "../../arch/x86/lib/memcpy_64.S"
/*
diff --git a/tools/perf/bench/mem-memcpy-x86-64-lib.c b/tools/perf/bench/mem-memcpy-x86-64-lib.c
new file mode 100644
index 000000000000..4130734dde84
--- /dev/null
+++ b/tools/perf/bench/mem-memcpy-x86-64-lib.c
@@ -0,0 +1,24 @@
+/*
+ * 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;
+}
--
2.14.4
Powered by blists - more mailing lists