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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-13 22:16:36 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-13 22:16:36 +0200
commit60f898eeaaa1c5d0162a4240bacf33a6c87ecef6 (patch)
tree23eeac4b1e9a616779d22c104dbc8bd45dfeefd1 /arch/x86/lib
parentMerge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kerne... (diff)
parentperf/x86/64: Report regs_user->ax too in get_regs_user() (diff)
downloadlinux-60f898eeaaa1c5d0162a4240bacf33a6c87ecef6.tar.xz
linux-60f898eeaaa1c5d0162a4240bacf33a6c87ecef6.zip
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar: "There were lots of changes in this development cycle: - over 100 separate cleanups, restructuring changes, speedups and fixes in the x86 system call, irq, trap and other entry code, part of a heroic effort to deobfuscate a decade old spaghetti asm code and its C code dependencies (Denys Vlasenko, Andy Lutomirski) - alternatives code fixes and enhancements (Borislav Petkov) - simplifications and cleanups to the compat code (Brian Gerst) - signal handling fixes and new x86 testcases (Andy Lutomirski) - various other fixes and cleanups By their nature many of these changes are risky - we tried to test them well on many different x86 systems (there are no known regressions), and they are split up finely to help bisection - but there's still a fair bit of residual risk left so caveat emptor" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits) perf/x86/64: Report regs_user->ax too in get_regs_user() perf/x86/64: Simplify regs_user->abi setting code in get_regs_user() perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user() perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user() x86/asm/entry/32: Tidy up JNZ instructions after TESTs x86/asm/entry/64: Reduce padding in execve stubs x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork x86/asm/entry/64: Simplify jumps in ret_from_fork x86/asm/entry/64: Remove a redundant jump x86/asm/entry/64: Optimize [v]fork/clone stubs x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat() x86/asm/entry/64: Use common code for rt_sigreturn() epilogue x86/asm/entry/64: Add forgotten CFI annotation x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout x86/asm/entry/64: Move opportunistic sysret code to syscall code path x86, selftests: Add sigreturn selftest x86/alternatives: Guard NOPs optimization x86/asm/entry: Clear EXTRA_REGS for all executable formats x86/signal: Remove pax argument from restore_sigcontext ...
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/atomic64_cx8_32.S50
-rw-r--r--arch/x86/lib/checksum_32.S64
-rw-r--r--arch/x86/lib/clear_page_64.S66
-rw-r--r--arch/x86/lib/copy_page_64.S37
-rw-r--r--arch/x86/lib/copy_user_64.S46
-rw-r--r--arch/x86/lib/csum-copy_64.S2
-rw-r--r--arch/x86/lib/insn.c13
-rw-r--r--arch/x86/lib/memcpy_64.S68
-rw-r--r--arch/x86/lib/memmove_64.S19
-rw-r--r--arch/x86/lib/memset_64.S61
-rw-r--r--arch/x86/lib/msr-reg.S24
-rw-r--r--arch/x86/lib/rwsem.S44
-rw-r--r--arch/x86/lib/thunk_32.S18
-rw-r--r--arch/x86/lib/thunk_64.S28
-rw-r--r--arch/x86/lib/x86-opcode-map.txt9
15 files changed, 223 insertions, 326 deletions
diff --git a/arch/x86/lib/atomic64_cx8_32.S b/arch/x86/lib/atomic64_cx8_32.S
index f5cc9eb1d51b..082a85167a5b 100644
--- a/arch/x86/lib/atomic64_cx8_32.S
+++ b/arch/x86/lib/atomic64_cx8_32.S
@@ -13,16 +13,6 @@
#include <asm/alternative-asm.h>
#include <asm/dwarf2.h>
-.macro SAVE reg
- pushl_cfi %\reg
- CFI_REL_OFFSET \reg, 0
-.endm
-
-.macro RESTORE reg
- popl_cfi %\reg
- CFI_RESTORE \reg
-.endm
-
.macro read64 reg
movl %ebx, %eax
movl %ecx, %edx
@@ -67,10 +57,10 @@ ENDPROC(atomic64_xchg_cx8)
.macro addsub_return func ins insc
ENTRY(atomic64_\func\()_return_cx8)
CFI_STARTPROC
- SAVE ebp
- SAVE ebx
- SAVE esi
- SAVE edi
+ pushl_cfi_reg ebp
+ pushl_cfi_reg ebx
+ pushl_cfi_reg esi
+ pushl_cfi_reg edi
movl %eax, %esi
movl %edx, %edi
@@ -89,10 +79,10 @@ ENTRY(atomic64_\func\()_return_cx8)
10:
movl %ebx, %eax
movl %ecx, %edx
- RESTORE edi
- RESTORE esi
- RESTORE ebx
- RESTORE ebp
+ popl_cfi_reg edi
+ popl_cfi_reg esi
+ popl_cfi_reg ebx
+ popl_cfi_reg ebp
ret
CFI_ENDPROC
ENDPROC(atomic64_\func\()_return_cx8)
@@ -104,7 +94,7 @@ addsub_return sub sub sbb
.macro incdec_return func ins insc
ENTRY(atomic64_\func\()_return_cx8)
CFI_STARTPROC
- SAVE ebx
+ pushl_cfi_reg ebx
read64 %esi
1:
@@ -119,7 +109,7 @@ ENTRY(atomic64_\func\()_return_cx8)
10:
movl %ebx, %eax
movl %ecx, %edx
- RESTORE ebx
+ popl_cfi_reg ebx
ret
CFI_ENDPROC
ENDPROC(atomic64_\func\()_return_cx8)
@@ -130,7 +120,7 @@ incdec_return dec sub sbb
ENTRY(atomic64_dec_if_positive_cx8)
CFI_STARTPROC
- SAVE ebx
+ pushl_cfi_reg ebx
read64 %esi
1:
@@ -146,18 +136,18 @@ ENTRY(atomic64_dec_if_positive_cx8)
2:
movl %ebx, %eax
movl %ecx, %edx
- RESTORE ebx
+ popl_cfi_reg ebx
ret
CFI_ENDPROC
ENDPROC(atomic64_dec_if_positive_cx8)
ENTRY(atomic64_add_unless_cx8)
CFI_STARTPROC
- SAVE ebp
- SAVE ebx
+ pushl_cfi_reg ebp
+ pushl_cfi_reg ebx
/* these just push these two parameters on the stack */
- SAVE edi
- SAVE ecx
+ pushl_cfi_reg edi
+ pushl_cfi_reg ecx
movl %eax, %ebp
movl %edx, %edi
@@ -179,8 +169,8 @@ ENTRY(atomic64_add_unless_cx8)
3:
addl $8, %esp
CFI_ADJUST_CFA_OFFSET -8
- RESTORE ebx
- RESTORE ebp
+ popl_cfi_reg ebx
+ popl_cfi_reg ebp
ret
4:
cmpl %edx, 4(%esp)
@@ -192,7 +182,7 @@ ENDPROC(atomic64_add_unless_cx8)
ENTRY(atomic64_inc_not_zero_cx8)
CFI_STARTPROC
- SAVE ebx
+ pushl_cfi_reg ebx
read64 %esi
1:
@@ -209,7 +199,7 @@ ENTRY(atomic64_inc_not_zero_cx8)
movl $1, %eax
3:
- RESTORE ebx
+ popl_cfi_reg ebx
ret
CFI_ENDPROC
ENDPROC(atomic64_inc_not_zero_cx8)
diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index e78b8eee6615..9bc944a91274 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -51,10 +51,8 @@ unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
*/
ENTRY(csum_partial)
CFI_STARTPROC
- pushl_cfi %esi
- CFI_REL_OFFSET esi, 0
- pushl_cfi %ebx
- CFI_REL_OFFSET ebx, 0
+ pushl_cfi_reg esi
+ pushl_cfi_reg ebx
movl 20(%esp),%eax # Function arg: unsigned int sum
movl 16(%esp),%ecx # Function arg: int len
movl 12(%esp),%esi # Function arg: unsigned char *buff
@@ -127,14 +125,12 @@ ENTRY(csum_partial)
6: addl %ecx,%eax
adcl $0, %eax
7:
- testl $1, 12(%esp)
+ testb $1, 12(%esp)
jz 8f
roll $8, %eax
8:
- popl_cfi %ebx
- CFI_RESTORE ebx
- popl_cfi %esi
- CFI_RESTORE esi
+ popl_cfi_reg ebx
+ popl_cfi_reg esi
ret
CFI_ENDPROC
ENDPROC(csum_partial)
@@ -145,10 +141,8 @@ ENDPROC(csum_partial)
ENTRY(csum_partial)
CFI_STARTPROC
- pushl_cfi %esi
- CFI_REL_OFFSET esi, 0
- pushl_cfi %ebx
- CFI_REL_OFFSET ebx, 0
+ pushl_cfi_reg esi
+ pushl_cfi_reg ebx
movl 20(%esp),%eax # Function arg: unsigned int sum
movl 16(%esp),%ecx # Function arg: int len
movl 12(%esp),%esi # Function arg: const unsigned char *buf
@@ -251,14 +245,12 @@ ENTRY(csum_partial)
addl %ebx,%eax
adcl $0,%eax
80:
- testl $1, 12(%esp)
+ testb $1, 12(%esp)
jz 90f
roll $8, %eax
90:
- popl_cfi %ebx
- CFI_RESTORE ebx
- popl_cfi %esi
- CFI_RESTORE esi
+ popl_cfi_reg ebx
+ popl_cfi_reg esi
ret
CFI_ENDPROC
ENDPROC(csum_partial)
@@ -298,12 +290,9 @@ ENTRY(csum_partial_copy_generic)
CFI_STARTPROC
subl $4,%esp
CFI_ADJUST_CFA_OFFSET 4
- pushl_cfi %edi
- CFI_REL_OFFSET edi, 0
- pushl_cfi %esi
- CFI_REL_OFFSET esi, 0
- pushl_cfi %ebx
- CFI_REL_OFFSET ebx, 0
+ pushl_cfi_reg edi
+ pushl_cfi_reg esi
+ pushl_cfi_reg ebx
movl ARGBASE+16(%esp),%eax # sum
movl ARGBASE+12(%esp),%ecx # len
movl ARGBASE+4(%esp),%esi # src
@@ -412,12 +401,9 @@ DST( movb %cl, (%edi) )
.previous
- popl_cfi %ebx
- CFI_RESTORE ebx
- popl_cfi %esi
- CFI_RESTORE esi
- popl_cfi %edi
- CFI_RESTORE edi
+ popl_cfi_reg ebx
+ popl_cfi_reg esi
+ popl_cfi_reg edi
popl_cfi %ecx # equivalent to addl $4,%esp
ret
CFI_ENDPROC
@@ -441,12 +427,9 @@ ENDPROC(csum_partial_copy_generic)
ENTRY(csum_partial_copy_generic)
CFI_STARTPROC
- pushl_cfi %ebx
- CFI_REL_OFFSET ebx, 0
- pushl_cfi %edi
- CFI_REL_OFFSET edi, 0
- pushl_cfi %esi
- CFI_REL_OFFSET esi, 0
+ pushl_cfi_reg ebx
+ pushl_cfi_reg edi
+ pushl_cfi_reg esi
movl ARGBASE+4(%esp),%esi #src
movl ARGBASE+8(%esp),%edi #dst
movl ARGBASE+12(%esp),%ecx #len
@@ -506,12 +489,9 @@ DST( movb %dl, (%edi) )
jmp 7b
.previous
- popl_cfi %esi
- CFI_RESTORE esi
- popl_cfi %edi
- CFI_RESTORE edi
- popl_cfi %ebx
- CFI_RESTORE ebx
+ popl_cfi_reg esi
+ popl_cfi_reg edi
+ popl_cfi_reg ebx
ret
CFI_ENDPROC
ENDPROC(csum_partial_copy_generic)
diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S
index f2145cfa12a6..e67e579c93bd 100644
--- a/arch/x86/lib/clear_page_64.S
+++ b/arch/x86/lib/clear_page_64.S
@@ -1,31 +1,35 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
+#include <asm/cpufeature.h>
#include <asm/alternative-asm.h>
/*
- * Zero a page.
- * rdi page
- */
-ENTRY(clear_page_c)
+ * Most CPUs support enhanced REP MOVSB/STOSB instructions. It is
+ * recommended to use this when possible and we do use them by default.
+ * If enhanced REP MOVSB/STOSB is not available, try to use fast string.
+ * Otherwise, use original.
+ */
+
+/*
+ * Zero a page.
+ * %rdi - page
+ */
+ENTRY(clear_page)
CFI_STARTPROC
+
+ ALTERNATIVE_2 "jmp clear_page_orig", "", X86_FEATURE_REP_GOOD, \
+ "jmp clear_page_c_e", X86_FEATURE_ERMS
+
movl $4096/8,%ecx
xorl %eax,%eax
rep stosq
ret
CFI_ENDPROC
-ENDPROC(clear_page_c)
+ENDPROC(clear_page)
-ENTRY(clear_page_c_e)
+ENTRY(clear_page_orig)
CFI_STARTPROC
- movl $4096,%ecx
- xorl %eax,%eax
- rep stosb
- ret
- CFI_ENDPROC
-ENDPROC(clear_page_c_e)
-ENTRY(clear_page)
- CFI_STARTPROC
xorl %eax,%eax
movl $4096/64,%ecx
.p2align 4
@@ -45,29 +49,13 @@ ENTRY(clear_page)
nop
ret
CFI_ENDPROC
-.Lclear_page_end:
-ENDPROC(clear_page)
-
- /*
- * Some CPUs support enhanced REP MOVSB/STOSB instructions.
- * It is recommended to use this when possible.
- * If enhanced REP MOVSB/STOSB is not available, try to use fast string.
- * Otherwise, use original function.
- *
- */
+ENDPROC(clear_page_orig)
-#include <asm/cpufeature.h>
-
- .section .altinstr_replacement,"ax"
-1: .byte 0xeb /* jmp <disp8> */
- .byte (clear_page_c - clear_page) - (2f - 1b) /* offset */
-2: .byte 0xeb /* jmp <disp8> */
- .byte (clear_page_c_e - clear_page) - (3f - 2b) /* offset */
-3:
- .previous
- .section .altinstructions,"a"
- altinstruction_entry clear_page,1b,X86_FEATURE_REP_GOOD,\
- .Lclear_page_end-clear_page, 2b-1b
- altinstruction_entry clear_page,2b,X86_FEATURE_ERMS, \
- .Lclear_page_end-clear_page,3b-2b
- .previous
+ENTRY(clear_page_c_e)
+ CFI_STARTPROC
+ movl $4096,%ecx
+ xorl %eax,%eax
+ rep stosb
+ ret
+ CFI_ENDPROC
+ENDPROC(clear_page_c_e)
diff --git a/arch/x86/lib/copy_page_64.S b/arch/x86/lib/copy_page_64.S
index 176cca67212b..8239dbcbf984 100644
--- a/arch/x86/lib/copy_page_64.S
+++ b/arch/x86/lib/copy_page_64.S
@@ -2,23 +2,26 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
+#include <asm/cpufeature.h>
#include <asm/alternative-asm.h>
+/*
+ * Some CPUs run faster using the string copy instructions (sane microcode).
+ * It is also a lot simpler. Use this when possible. But, don't use streaming
+ * copy unless the CPU indicates X86_FEATURE_REP_GOOD. Could vary the
+ * prefetch distance based on SMP/UP.
+ */
ALIGN
-copy_page_rep:
+ENTRY(copy_page)
CFI_STARTPROC
+ ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
movl $4096/8, %ecx
rep movsq
ret
CFI_ENDPROC
-ENDPROC(copy_page_rep)
-
-/*
- * Don't use streaming copy unless the CPU indicates X86_FEATURE_REP_GOOD.
- * Could vary the prefetch distance based on SMP/UP.
-*/
+ENDPROC(copy_page)
-ENTRY(copy_page)
+ENTRY(copy_page_regs)
CFI_STARTPROC
subq $2*8, %rsp
CFI_ADJUST_CFA_OFFSET 2*8
@@ -90,21 +93,5 @@ ENTRY(copy_page)
addq $2*8, %rsp
CFI_ADJUST_CFA_OFFSET -2*8
ret
-.Lcopy_page_end:
CFI_ENDPROC
-ENDPROC(copy_page)
-
- /* Some CPUs run faster using the string copy instructions.
- It is also a lot simpler. Use this when possible */
-
-#include <asm/cpufeature.h>
-
- .section .altinstr_replacement,"ax"
-1: .byte 0xeb /* jmp <disp8> */
- .byte (copy_page_rep - copy_page) - (2f - 1b) /* offset */
-2:
- .previous
- .section .altinstructions,"a"
- altinstruction_entry copy_page, 1b, X86_FEATURE_REP_GOOD, \
- .Lcopy_page_end-copy_page, 2b-1b
- .previous
+ENDPROC(copy_page_regs)
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index dee945d55594..fa997dfaef24 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -8,9 +8,6 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
-
-#define FIX_ALIGNMENT 1
-
#include <asm/current.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
@@ -19,33 +16,7 @@
#include <asm/asm.h>
#include <asm/smap.h>
-/*
- * By placing feature2 after feature1 in altinstructions section, we logically
- * implement:
- * If CPU has feature2, jmp to alt2 is used
- * else if CPU has feature1, jmp to alt1 is used
- * else jmp to orig is used.
- */
- .macro ALTERNATIVE_JUMP feature1,feature2,orig,alt1,alt2
-0:
- .byte 0xe9 /* 32bit jump */
- .long \orig-1f /* by default jump to orig */
-1:
- .section .altinstr_replacement,"ax"
-2: .byte 0xe9 /* near jump with 32bit immediate */
- .long \alt1-1b /* offset */ /* or alternatively to alt1 */
-3: .byte 0xe9 /* near jump with 32bit immediate */
- .long \alt2-1b /* offset */ /* or alternatively to alt2 */
- .previous
-
- .section .altinstructions,"a"
- altinstruction_entry 0b,2b,\feature1,5,5
- altinstruction_entry 0b,3b,\feature2,5,5
- .previous
- .endm
-
.macro ALIGN_DESTINATION
-#ifdef FIX_ALIGNMENT
/* check for bad alignment of destination */
movl %edi,%ecx
andl $7,%ecx
@@ -67,7 +38,6 @@
_ASM_EXTABLE(100b,103b)
_ASM_EXTABLE(101b,103b)
-#endif
.endm
/* Standard copy_to_user with segment limit checking */
@@ -79,9 +49,11 @@ ENTRY(_copy_to_user)
jc bad_to_user
cmpq TI_addr_limit(%rax),%rcx
ja bad_to_user
- ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,X86_FEATURE_ERMS, \
- copy_user_generic_unrolled,copy_user_generic_string, \
- copy_user_enhanced_fast_string
+ ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
+ "jmp copy_user_generic_string", \
+ X86_FEATURE_REP_GOOD, \
+ "jmp copy_user_enhanced_fast_string", \
+ X86_FEATURE_ERMS
CFI_ENDPROC
ENDPROC(_copy_to_user)
@@ -94,9 +66,11 @@ ENTRY(_copy_from_user)
jc bad_from_user
cmpq TI_addr_limit(%rax),%rcx
ja bad_from_user
- ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,X86_FEATURE_ERMS, \
- copy_user_generic_unrolled,copy_user_generic_string, \
- copy_user_enhanced_fast_string
+ ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
+ "jmp copy_user_generic_string", \
+ X86_FEATURE_REP_GOOD, \
+ "jmp copy_user_enhanced_fast_string", \
+ X86_FEATURE_ERMS
CFI_ENDPROC
ENDPROC(_copy_from_user)
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S
index 2419d5fefae3..9734182966f3 100644
--- a/arch/x86/lib/csum-copy_64.S
+++ b/arch/x86/lib/csum-copy_64.S
@@ -196,7 +196,7 @@ ENTRY(csum_partial_copy_generic)
/* handle last odd byte */
.Lhandle_1:
- testl $1, %r10d
+ testb $1, %r10b
jz .Lende
xorl %ebx, %ebx
source
diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 1313ae6b478b..8f72b334aea0 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -52,6 +52,13 @@
*/
void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
{
+ /*
+ * Instructions longer than MAX_INSN_SIZE (15 bytes) are invalid
+ * even if the input buffer is long enough to hold them.
+ */
+ if (buf_len > MAX_INSN_SIZE)
+ buf_len = MAX_INSN_SIZE;
+
memset(insn, 0, sizeof(*insn));
insn->kaddr = kaddr;
insn->end_kaddr = kaddr + buf_len;
@@ -164,6 +171,12 @@ found:
/* VEX.W overrides opnd_size */
insn->opnd_bytes = 8;
} else {
+ /*
+ * For VEX2, fake VEX3-like byte#2.
+ * Makes it easier to decode vex.W, vex.vvvv,
+ * vex.L and vex.pp. Masking with 0x7f sets vex.W == 0.
+ */
+ insn->vex_prefix.bytes[2] = b2 & 0x7f;
insn->vex_prefix.nbytes = 2;
insn->next_byte += 2;
}
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 89b53c9968e7..b046664f5a1c 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -1,12 +1,20 @@
/* Copyright 2002 Andi Kleen */
#include <linux/linkage.h>
-
#include <asm/cpufeature.h>
#include <asm/dwarf2.h>
#include <asm/alternative-asm.h>
/*
+ * We build a jump to memcpy_orig by default which gets NOPped out on
+ * the majority of x86 CPUs which set REP_GOOD. In addition, CPUs which
+ * have the enhanced REP MOVSB/STOSB feature (ERMS), change those NOPs
+ * to a jmp to memcpy_erms which does the REP; MOVSB mem copy.
+ */
+
+.weak memcpy
+
+/*
* memcpy - Copy a memory block.
*
* Input:
@@ -17,15 +25,11 @@
* Output:
* rax original destination
*/
+ENTRY(__memcpy)
+ENTRY(memcpy)
+ ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
+ "jmp memcpy_erms", X86_FEATURE_ERMS
-/*
- * memcpy_c() - fast string ops (REP MOVSQ) based variant.
- *
- * This gets patched over the unrolled variant (below) via the
- * alternative instructions framework:
- */
- .section .altinstr_replacement, "ax", @progbits
-.Lmemcpy_c:
movq %rdi, %rax
movq %rdx, %rcx
shrq $3, %rcx
@@ -34,29 +38,21 @@
movl %edx, %ecx
rep movsb
ret
-.Lmemcpy_e:
- .previous
+ENDPROC(memcpy)
+ENDPROC(__memcpy)
/*
- * memcpy_c_e() - enhanced fast string memcpy. This is faster and simpler than
- * memcpy_c. Use memcpy_c_e when possible.
- *
- * This gets patched over the unrolled variant (below) via the
- * alternative instructions framework:
+ * memcpy_erms() - enhanced fast string memcpy. This is faster and
+ * simpler than memcpy. Use memcpy_erms when possible.
*/
- .section .altinstr_replacement, "ax", @progbits
-.Lmemcpy_c_e:
+ENTRY(memcpy_erms)
movq %rdi, %rax
movq %rdx, %rcx
rep movsb
ret
-.Lmemcpy_e_e:
- .previous
-
-.weak memcpy
+ENDPROC(memcpy_erms)
-ENTRY(__memcpy)
-ENTRY(memcpy)
+ENTRY(memcpy_orig)
CFI_STARTPROC
movq %rdi, %rax
@@ -183,26 +179,4 @@ ENTRY(memcpy)
.Lend:
retq
CFI_ENDPROC
-ENDPROC(memcpy)
-ENDPROC(__memcpy)
-
- /*
- * Some CPUs are adding enhanced REP MOVSB/STOSB feature
- * If the feature is supported, memcpy_c_e() is the first choice.
- * If enhanced rep movsb copy is not available, use fast string copy
- * memcpy_c() when possible. This is faster and code is simpler than
- * original memcpy().
- * Otherwise, original memcpy() is used.
- * In .altinstructions section, ERMS feature is placed after REG_GOOD
- * feature to implement the right patch order.
- *
- * Replace only beginning, memcpy is used to apply alternatives,
- * so it is silly to overwrite itself with nops - reboot is the
- * only outcome...
- */
- .section .altinstructions, "a"
- altinstruction_entry __memcpy,.Lmemcpy_c,X86_FEATURE_REP_GOOD,\
- .Lmemcpy_e-.Lmemcpy_c,.Lmemcpy_e-.Lmemcpy_c
- altinstruction_entry __memcpy,.Lmemcpy_c_e,X86_FEATURE_ERMS, \
- .Lmemcpy_e_e-.Lmemcpy_c_e,.Lmemcpy_e_e-.Lmemcpy_c_e
- .previous
+ENDPROC(memcpy_orig)
diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index 9c4b530575da..0f8a0d0331b9 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -5,7 +5,6 @@
* This assembly file is re-written from memmove_64.c file.
* - Copyright 2011 Fenghua Yu <fenghua.yu@intel.com>
*/
-#define _STRING_C
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/cpufeature.h>
@@ -44,6 +43,8 @@ ENTRY(__memmove)
jg 2f
.Lmemmove_begin_forward:
+ ALTERNATIVE "", "movq %rdx, %rcx; rep movsb; retq", X86_FEATURE_ERMS
+
/*
* movsq instruction have many startup latency
* so we handle small size by general register.
@@ -207,21 +208,5 @@ ENTRY(__memmove)
13:
retq
CFI_ENDPROC
-
- .section .altinstr_replacement,"ax"
-.Lmemmove_begin_forward_efs:
- /* Forward moving data. */
- movq %rdx, %rcx
- rep movsb
- retq
-.Lmemmove_end_forward_efs:
- .previous
-
- .section .altinstructions,"a"
- altinstruction_entry .Lmemmove_begin_forward, \
- .Lmemmove_begin_forward_efs,X86_FEATURE_ERMS, \
- .Lmemmove_end_forward-.Lmemmove_begin_forward, \
- .Lmemmove_end_forward_efs-.Lmemmove_begin_forward_efs
- .previous
ENDPROC(__memmove)
ENDPROC(memmove)
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index 6f44935c6a60..93118fb23976 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -5,19 +5,30 @@
#include <asm/cpufeature.h>
#include <asm/alternative-asm.h>
+.weak memset
+
/*
* ISO C memset - set a memory block to a byte value. This function uses fast
* string to get better performance than the original function. The code is
* simpler and shorter than the orignal function as well.
- *
+ *
* rdi destination
- * rsi value (char)
- * rdx count (bytes)
- *
+ * rsi value (char)
+ * rdx count (bytes)
+ *
* rax original destination
- */
- .section .altinstr_replacement, "ax", @progbits
-.Lmemset_c:
+ */
+ENTRY(memset)
+ENTRY(__memset)
+ /*
+ * Some CPUs support enhanced REP MOVSB/STOSB feature. It is recommended
+ * to use it when possible. If not available, use fast string instructions.
+ *
+ * Otherwise, use original memset function.
+ */
+ ALTERNATIVE_2 "jmp memset_orig", "", X86_FEATURE_REP_GOOD, \
+ "jmp memset_erms", X86_FEATURE_ERMS
+
movq %rdi,%r9
movq %rdx,%rcx
andl $7,%edx
@@ -31,8 +42,8 @@
rep stosb
movq %r9,%rax
ret
-.Lmemset_e:
- .previous
+ENDPROC(memset)
+ENDPROC(__memset)
/*
* ISO C memset - set a memory block to a byte value. This function uses
@@ -45,21 +56,16 @@
*
* rax original destination
*/
- .section .altinstr_replacement, "ax", @progbits
-.Lmemset_c_e:
+ENTRY(memset_erms)
movq %rdi,%r9
movb %sil,%al
movq %rdx,%rcx
rep stosb
movq %r9,%rax
ret
-.Lmemset_e_e:
- .previous
-
-.weak memset
+ENDPROC(memset_erms)
-ENTRY(memset)
-ENTRY(__memset)
+ENTRY(memset_orig)
CFI_STARTPROC
movq %rdi,%r10
@@ -134,23 +140,4 @@ ENTRY(__memset)
jmp .Lafter_bad_alignment
.Lfinal:
CFI_ENDPROC
-ENDPROC(memset)
-ENDPROC(__memset)
-
- /* Some CPUs support enhanced REP MOVSB/STOSB feature.
- * It is recommended to use this when possible.
- *
- * If enhanced REP MOVSB/STOSB feature is not available, use fast string
- * instructions.
- *
- * Otherwise, use original memset function.
- *
- * In .altinstructions section, ERMS feature is placed after REG_GOOD
- * feature to implement the right patch order.
- */
- .section .altinstructions,"a"
- altinstruction_entry __memset,.Lmemset_c,X86_FEATURE_REP_GOOD,\
- .Lfinal-__memset,.Lmemset_e-.Lmemset_c
- altinstruction_entry __memset,.Lmemset_c_e,X86_FEATURE_ERMS, \
- .Lfinal-__memset,.Lmemset_e_e-.Lmemset_c_e
- .previous
+ENDPROC(memset_orig)
diff --git a/arch/x86/lib/msr-reg.S b/arch/x86/lib/msr-reg.S
index f6d13eefad10..3ca5218fbece 100644
--- a/arch/x86/lib/msr-reg.S
+++ b/arch/x86/lib/msr-reg.S
@@ -14,8 +14,8 @@
.macro op_safe_regs op
ENTRY(\op\()_safe_regs)
CFI_STARTPROC
- pushq_cfi %rbx
- pushq_cfi %rbp
+ pushq_cfi_reg rbx
+ pushq_cfi_reg rbp
movq %rdi, %r10 /* Save pointer */
xorl %r11d, %r11d /* Return value */
movl (%rdi), %eax
@@ -35,8 +35,8 @@ ENTRY(\op\()_safe_regs)
movl %ebp, 20(%r10)
movl %esi, 24(%r10)
movl %edi, 28(%r10)
- popq_cfi %rbp
- popq_cfi %rbx
+ popq_cfi_reg rbp
+ popq_cfi_reg rbx
ret
3:
CFI_RESTORE_STATE
@@ -53,10 +53,10 @@ ENDPROC(\op\()_safe_regs)
.macro op_safe_regs op
ENTRY(\op\()_safe_regs)
CFI_STARTPROC
- pushl_cfi %ebx
- pushl_cfi %ebp
- pushl_cfi %esi
- pushl_cfi %edi
+ pushl_cfi_reg ebx
+ pushl_cfi_reg ebp
+ pushl_cfi_reg esi
+ pushl_cfi_reg edi
pushl_cfi $0 /* Return value */
pushl_cfi %eax
movl 4(%eax), %ecx
@@ -80,10 +80,10 @@ ENTRY(\op\()_safe_regs)
movl %esi, 24(%eax)
movl %edi, 28(%eax)
popl_cfi %eax
- popl_cfi %edi
- popl_cfi %esi
- popl_cfi %ebp
- popl_cfi %ebx
+ popl_cfi_reg edi
+ popl_cfi_reg esi
+ popl_cfi_reg ebp
+ popl_cfi_reg ebx
ret
3:
CFI_RESTORE_STATE
diff --git a/arch/x86/lib/rwsem.S b/arch/x86/lib/rwsem.S
index 5dff5f042468..2322abe4da3b 100644
--- a/arch/x86/lib/rwsem.S
+++ b/arch/x86/lib/rwsem.S
@@ -34,10 +34,10 @@
*/
#define save_common_regs \
- pushl_cfi %ecx; CFI_REL_OFFSET ecx, 0
+ pushl_cfi_reg ecx
#define restore_common_regs \
- popl_cfi %ecx; CFI_RESTORE ecx
+ popl_cfi_reg ecx
/* Avoid uglifying the argument copying x86-64 needs to do. */
.macro movq src, dst
@@ -64,22 +64,22 @@
*/
#define save_common_regs \
- pushq_cfi %rdi; CFI_REL_OFFSET rdi, 0; \
- pushq_cfi %rsi; CFI_REL_OFFSET rsi, 0; \
- pushq_cfi %rcx; CFI_REL_OFFSET rcx, 0; \
- pushq_cfi %r8; CFI_REL_OFFSET r8, 0; \
- pushq_cfi %r9; CFI_REL_OFFSET r9, 0; \
- pushq_cfi %r10; CFI_REL_OFFSET r10, 0; \
- pushq_cfi %r11; CFI_REL_OFFSET r11, 0
+ pushq_cfi_reg rdi; \
+ pushq_cfi_reg rsi; \
+ pushq_cfi_reg rcx; \
+ pushq_cfi_reg r8; \
+ pushq_cfi_reg r9; \
+ pushq_cfi_reg r10; \
+ pushq_cfi_reg r11
#define restore_common_regs \
- popq_cfi %r11; CFI_RESTORE r11; \
- popq_cfi %r10; CFI_RESTORE r10; \
- popq_cfi %r9; CFI_RESTORE r9; \
- popq_cfi %r8; CFI_RESTORE r8; \
- popq_cfi %rcx; CFI_RESTORE rcx; \
- popq_cfi %rsi; CFI_RESTORE rsi; \
- popq_cfi %rdi; CFI_RESTORE rdi
+ popq_cfi_reg r11; \
+ popq_cfi_reg r10; \
+ popq_cfi_reg r9; \
+ popq_cfi_reg r8; \
+ popq_cfi_reg rcx; \
+ popq_cfi_reg rsi; \
+ popq_cfi_reg rdi
#endif
@@ -87,12 +87,10 @@
ENTRY(call_rwsem_down_read_failed)
CFI_STARTPROC
save_common_regs
- __ASM_SIZE(push,_cfi) %__ASM_REG(dx)
- CFI_REL_OFFSET __ASM_REG(dx), 0
+ __ASM_SIZE(push,_cfi_reg) __ASM_REG(dx)
movq %rax,%rdi
call rwsem_down_read_failed
- __ASM_SIZE(pop,_cfi) %__ASM_REG(dx)
- CFI_RESTORE __ASM_REG(dx)
+ __ASM_SIZE(pop,_cfi_reg) __ASM_REG(dx)
restore_common_regs
ret
CFI_ENDPROC
@@ -124,12 +122,10 @@ ENDPROC(call_rwsem_wake)
ENTRY(call_rwsem_downgrade_wake)
CFI_STARTPROC
save_common_regs
- __ASM_SIZE(push,_cfi) %__ASM_REG(dx)
- CFI_REL_OFFSET __ASM_REG(dx), 0
+ __ASM_SIZE(push,_cfi_reg) __ASM_REG(dx)
movq %rax,%rdi
call rwsem_downgrade_wake
- __ASM_SIZE(pop,_cfi) %__ASM_REG(dx)
- CFI_RESTORE __ASM_REG(dx)
+ __ASM_SIZE(pop,_cfi_reg) __ASM_REG(dx)
restore_common_regs
ret
CFI_ENDPROC
diff --git a/arch/x86/lib/thunk_32.S b/arch/x86/lib/thunk_32.S
index e28cdaf5ac2c..5eb715087b80 100644
--- a/arch/x86/lib/thunk_32.S
+++ b/arch/x86/lib/thunk_32.S
@@ -13,12 +13,9 @@
.globl \name
\name:
CFI_STARTPROC
- pushl_cfi %eax
- CFI_REL_OFFSET eax, 0
- pushl_cfi %ecx
- CFI_REL_OFFSET ecx, 0
- pushl_cfi %edx
- CFI_REL_OFFSET edx, 0
+ pushl_cfi_reg eax
+ pushl_cfi_reg ecx
+ pushl_cfi_reg edx
.if \put_ret_addr_in_eax
/* Place EIP in the arg1 */
@@ -26,12 +23,9 @@
.endif
call \func
- popl_cfi %edx
- CFI_RESTORE edx
- popl_cfi %ecx
- CFI_RESTORE ecx
- popl_cfi %eax
- CFI_RESTORE eax
+ popl_cfi_reg edx
+ popl_cfi_reg ecx
+ popl_cfi_reg eax
ret
CFI_ENDPROC
_ASM_NOKPROBE(\name)
diff --git a/arch/x86/lib/thunk_64.S b/arch/x86/lib/thunk_64.S
index b30b5ebd614a..f89ba4e93025 100644
--- a/arch/x86/lib/thunk_64.S
+++ b/arch/x86/lib/thunk_64.S
@@ -17,9 +17,18 @@
CFI_STARTPROC
/* this one pushes 9 elems, the next one would be %rIP */
- SAVE_ARGS
+ pushq_cfi_reg rdi
+ pushq_cfi_reg rsi
+ pushq_cfi_reg rdx
+ pushq_cfi_reg rcx
+ pushq_cfi_reg rax
+ pushq_cfi_reg r8
+ pushq_cfi_reg r9
+ pushq_cfi_reg r10
+ pushq_cfi_reg r11
.if \put_ret_addr_in_rdi
+ /* 9*8(%rsp) is return addr on stack */
movq_cfi_restore 9*8, rdi
.endif
@@ -45,11 +54,22 @@
#endif
#endif
- /* SAVE_ARGS below is used only for the .cfi directives it contains. */
+#if defined(CONFIG_TRACE_IRQFLAGS) \
+ || defined(CONFIG_DEBUG_LOCK_ALLOC) \
+ || defined(CONFIG_PREEMPT)
CFI_STARTPROC
- SAVE_ARGS
+ CFI_ADJUST_CFA_OFFSET 9*8
restore:
- RESTORE_ARGS
+ popq_cfi_reg r11
+ popq_cfi_reg r10
+ popq_cfi_reg r9
+ popq_cfi_reg r8
+ popq_cfi_reg rax
+ popq_cfi_reg rcx
+ popq_cfi_reg rdx
+ popq_cfi_reg rsi
+ popq_cfi_reg rdi
ret
CFI_ENDPROC
_ASM_NOKPROBE(restore)
+#endif
diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt
index 1a2be7c6895d..816488c0b97e 100644
--- a/arch/x86/lib/x86-opcode-map.txt
+++ b/arch/x86/lib/x86-opcode-map.txt
@@ -273,6 +273,9 @@ dd: ESC
de: ESC
df: ESC
# 0xe0 - 0xef
+# Note: "forced64" is Intel CPU behavior: they ignore 0x66 prefix
+# in 64-bit mode. AMD CPUs accept 0x66 prefix, it causes RIP truncation
+# to 16 bits. In 32-bit mode, 0x66 is accepted by both Intel and AMD.
e0: LOOPNE/LOOPNZ Jb (f64)
e1: LOOPE/LOOPZ Jb (f64)
e2: LOOP Jb (f64)
@@ -281,6 +284,10 @@ e4: IN AL,Ib
e5: IN eAX,Ib
e6: OUT Ib,AL
e7: OUT Ib,eAX
+# With 0x66 prefix in 64-bit mode, for AMD CPUs immediate offset
+# in "near" jumps and calls is 16-bit. For CALL,
+# push of return address is 16-bit wide, RSP is decremented by 2
+# but is not truncated to 16 bits, unlike RIP.
e8: CALL Jz (f64)
e9: JMP-near Jz (f64)
ea: JMP-far Ap (i64)
@@ -456,6 +463,7 @@ AVXcode: 1
7e: movd/q Ey,Pd | vmovd/q Ey,Vy (66),(v1) | vmovq Vq,Wq (F3),(v1)
7f: movq Qq,Pq | vmovdqa Wx,Vx (66) | vmovdqu Wx,Vx (F3)
# 0x0f 0x80-0x8f
+# Note: "forced64" is Intel CPU behavior (see comment about CALL insn).
80: JO Jz (f64)
81: JNO Jz (f64)
82: JB/JC/JNAE Jz (f64)
@@ -842,6 +850,7 @@ EndTable
GrpTable: Grp5
0: INC Ev
1: DEC Ev
+# Note: "forced64" is Intel CPU behavior (see comment about CALL insn).
2: CALLN Ev (f64)
3: CALLF Ep
4: JMPN Ev (f64)