Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
- Add UMIP emulation/spoofing for 64-bit processes as well, because of
Wine based gaming.
- Clean up symbols/labels in low level asm code
- Add an assembly optimized mul_u64_u32_div() implementation on x86-64.
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/umip: Add emulation (spoofing) for UMIP covered instructions in 64-bit processes as well
x86/asm: Make some functions local labels
x86/asm/suspend: Get rid of bogus_64_magic
x86/math64: Provide a sane mul_u64_u32_div() implementation for x86_64
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 37380c0..5e30eaa 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -140,7 +140,7 @@
/*
* Jump to the relocated address.
*/
- leal relocated(%ebx), %eax
+ leal .Lrelocated(%ebx), %eax
jmp *%eax
ENDPROC(startup_32)
@@ -209,7 +209,7 @@
#endif
.text
-relocated:
+.Lrelocated:
/*
* Clear BSS (stack is currently empty)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 6233ae3..d98cd48 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -87,7 +87,7 @@
call verify_cpu
testl %eax, %eax
- jnz no_longmode
+ jnz .Lno_longmode
/*
* Compute the delta between where we were compiled to run at
@@ -322,7 +322,7 @@
1: popq %rdi
subq $1b, %rdi
- call adjust_got
+ call .Ladjust_got
/*
* At this point we are in long mode with 4-level paging enabled,
@@ -421,7 +421,7 @@
/* The new adjustment is the relocation address */
movq %rbx, %rdi
- call adjust_got
+ call .Ladjust_got
/*
* Copy the compressed kernel to the end of our buffer
@@ -440,7 +440,7 @@
/*
* Jump to the relocated address.
*/
- leaq relocated(%rbx), %rax
+ leaq .Lrelocated(%rbx), %rax
jmp *%rax
#ifdef CONFIG_EFI_STUB
@@ -511,7 +511,7 @@
#endif
.text
-relocated:
+.Lrelocated:
/*
* Clear BSS (stack is currently empty)
@@ -548,7 +548,7 @@
* first time we touch GOT).
* RDI is the new adjustment to apply.
*/
-adjust_got:
+.Ladjust_got:
/* Walk through the GOT adding the address to the entries */
leaq _got(%rip), %rdx
leaq _egot(%rip), %rcx
@@ -622,7 +622,7 @@
movl %eax, %cr4
/* Calculate address of paging_enabled() once we are executing in the trampoline */
- leal paging_enabled - trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_OFFSET(%ecx), %eax
+ leal .Lpaging_enabled - trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_OFFSET(%ecx), %eax
/* Prepare the stack for far return to Long Mode */
pushl $__KERNEL_CS
@@ -635,7 +635,7 @@
lret
.code64
-paging_enabled:
+.Lpaging_enabled:
/* Return from the trampoline */
jmp *%rdi
@@ -647,7 +647,7 @@
.org trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_SIZE
.code32
-no_longmode:
+.Lno_longmode:
/* This isn't an x86-64 CPU, so hang intentionally, we cannot continue */
1:
hlt
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index af077de..b7c3ea4 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1058,10 +1058,10 @@
ENDPROC(native_load_gs_index)
EXPORT_SYMBOL(native_load_gs_index)
- _ASM_EXTABLE(.Lgs_change, bad_gs)
+ _ASM_EXTABLE(.Lgs_change, .Lbad_gs)
.section .fixup, "ax"
/* running with kernelgs */
-bad_gs:
+.Lbad_gs:
SWAPGS /* switch back to user gs */
.macro ZAP_GS
/* This can't be a string because the preprocessor needs to see it. */
diff --git a/arch/x86/include/asm/div64.h b/arch/x86/include/asm/div64.h
index 20a4615..9b8cb50 100644
--- a/arch/x86/include/asm/div64.h
+++ b/arch/x86/include/asm/div64.h
@@ -73,6 +73,19 @@
#else
# include <asm-generic/div64.h>
+
+static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 div)
+{
+ u64 q;
+
+ asm ("mulq %2; divq %3" : "=a" (q)
+ : "a" (a), "rm" ((u64)mul), "rm" ((u64)div)
+ : "rdx");
+
+ return q;
+}
+#define mul_u64_u32_div mul_u64_u32_div
+
#endif /* CONFIG_X86_32 */
#endif /* _ASM_X86_DIV64_H */
diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index b0715c3..7f9ade1 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -18,8 +18,13 @@
movq saved_magic, %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
- jne bogus_64_magic
+ je 2f
+ /* stop here on a saved_magic mismatch */
+ movq $0xbad6d61676963, %rcx
+1:
+ jmp 1b
+2:
movw $__KERNEL_DS, %ax
movw %ax, %ss
movw %ax, %ds
@@ -37,9 +42,6 @@
jmp *%rax
ENDPROC(wakeup_long64)
-bogus_64_magic:
- jmp bogus_64_magic
-
ENTRY(do_suspend_lowlevel)
FRAME_BEGIN
subq $8, %rsp
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index 5b345ad..548fefe 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -19,7 +19,7 @@
/** DOC: Emulation for User-Mode Instruction Prevention (UMIP)
*
* The feature User-Mode Instruction Prevention present in recent Intel
- * processor prevents a group of instructions (sgdt, sidt, sldt, smsw, and str)
+ * processor prevents a group of instructions (SGDT, SIDT, SLDT, SMSW and STR)
* from being executed with CPL > 0. Otherwise, a general protection fault is
* issued.
*
@@ -36,8 +36,8 @@
* DOSEMU2) rely on this subset of instructions to function.
*
* The instructions protected by UMIP can be split in two groups. Those which
- * return a kernel memory address (sgdt and sidt) and those which return a
- * value (sldt, str and smsw).
+ * return a kernel memory address (SGDT and SIDT) and those which return a
+ * value (SLDT, STR and SMSW).
*
* For the instructions that return a kernel memory address, applications
* such as WineHQ rely on the result being located in the kernel memory space,
@@ -45,15 +45,13 @@
* value that, lies close to the top of the kernel memory. The limit for the GDT
* and the IDT are set to zero.
*
- * Given that sldt and str are not commonly used in programs that run on WineHQ
+ * Given that SLDT and STR are not commonly used in programs that run on WineHQ
* or DOSEMU2, they are not emulated.
*
* The instruction smsw is emulated to return the value that the register CR0
* has at boot time as set in the head_32.
*
- * Also, emulation is provided only for 32-bit processes; 64-bit processes
- * that attempt to use the instructions that UMIP protects will receive the
- * SIGSEGV signal issued as a consequence of the general protection fault.
+ * Emulation is provided for both 32-bit and 64-bit processes.
*
* Care is taken to appropriately emulate the results when segmentation is
* used. That is, rather than relying on USER_DS and USER_CS, the function
@@ -63,17 +61,18 @@
* application uses a local descriptor table.
*/
-#define UMIP_DUMMY_GDT_BASE 0xfffe0000
-#define UMIP_DUMMY_IDT_BASE 0xffff0000
+#define UMIP_DUMMY_GDT_BASE 0xfffffffffffe0000ULL
+#define UMIP_DUMMY_IDT_BASE 0xffffffffffff0000ULL
/*
* The SGDT and SIDT instructions store the contents of the global descriptor
* table and interrupt table registers, respectively. The destination is a
* memory operand of X+2 bytes. X bytes are used to store the base address of
- * the table and 2 bytes are used to store the limit. In 32-bit processes, the
- * only processes for which emulation is provided, X has a value of 4.
+ * the table and 2 bytes are used to store the limit. In 32-bit processes X
+ * has a value of 4, in 64-bit processes X has a value of 8.
*/
-#define UMIP_GDT_IDT_BASE_SIZE 4
+#define UMIP_GDT_IDT_BASE_SIZE_64BIT 8
+#define UMIP_GDT_IDT_BASE_SIZE_32BIT 4
#define UMIP_GDT_IDT_LIMIT_SIZE 2
#define UMIP_INST_SGDT 0 /* 0F 01 /0 */
@@ -189,6 +188,7 @@
* @umip_inst: A constant indicating the instruction to emulate
* @data: Buffer into which the dummy result is stored
* @data_size: Size of the emulated result
+ * @x86_64: true if process is 64-bit, false otherwise
*
* Emulate an instruction protected by UMIP and provide a dummy result. The
* result of the emulation is saved in @data. The size of the results depends
@@ -202,11 +202,8 @@
* 0 on success, -EINVAL on error while emulating.
*/
static int emulate_umip_insn(struct insn *insn, int umip_inst,
- unsigned char *data, int *data_size)
+ unsigned char *data, int *data_size, bool x86_64)
{
- unsigned long dummy_base_addr, dummy_value;
- unsigned short dummy_limit = 0;
-
if (!data || !data_size || !insn)
return -EINVAL;
/*
@@ -219,6 +216,9 @@
* is always returned irrespective of the operand size.
*/
if (umip_inst == UMIP_INST_SGDT || umip_inst == UMIP_INST_SIDT) {
+ u64 dummy_base_addr;
+ u16 dummy_limit = 0;
+
/* SGDT and SIDT do not use registers operands. */
if (X86_MODRM_MOD(insn->modrm.value) == 3)
return -EINVAL;
@@ -228,13 +228,24 @@
else
dummy_base_addr = UMIP_DUMMY_IDT_BASE;
- *data_size = UMIP_GDT_IDT_LIMIT_SIZE + UMIP_GDT_IDT_BASE_SIZE;
+ /*
+ * 64-bit processes use the entire dummy base address.
+ * 32-bit processes use the lower 32 bits of the base address.
+ * dummy_base_addr is always 64 bits, but we memcpy the correct
+ * number of bytes from it to the destination.
+ */
+ if (x86_64)
+ *data_size = UMIP_GDT_IDT_BASE_SIZE_64BIT;
+ else
+ *data_size = UMIP_GDT_IDT_BASE_SIZE_32BIT;
- memcpy(data + 2, &dummy_base_addr, UMIP_GDT_IDT_BASE_SIZE);
+ memcpy(data + 2, &dummy_base_addr, *data_size);
+
+ *data_size += UMIP_GDT_IDT_LIMIT_SIZE;
memcpy(data, &dummy_limit, UMIP_GDT_IDT_LIMIT_SIZE);
} else if (umip_inst == UMIP_INST_SMSW) {
- dummy_value = CR0_STATE;
+ unsigned long dummy_value = CR0_STATE;
/*
* Even though the CR0 register has 4 bytes, the number
@@ -290,11 +301,10 @@
* fixup_umip_exception() - Fixup a general protection fault caused by UMIP
* @regs: Registers as saved when entering the #GP handler
*
- * The instructions sgdt, sidt, str, smsw, sldt cause a general protection
- * fault if executed with CPL > 0 (i.e., from user space). If the offending
- * user-space process is not in long mode, this function fixes the exception
- * up and provides dummy results for sgdt, sidt and smsw; str and sldt are not
- * fixed up. Also long mode user-space processes are not fixed up.
+ * The instructions SGDT, SIDT, STR, SMSW and SLDT cause a general protection
+ * fault if executed with CPL > 0 (i.e., from user space). This function fixes
+ * the exception up and provides dummy results for SGDT, SIDT and SMSW; STR
+ * and SLDT are not fixed up.
*
* If operands are memory addresses, results are copied to user-space memory as
* indicated by the instruction pointed by eIP using the registers indicated in
@@ -373,13 +383,14 @@
umip_pr_warning(regs, "%s instruction cannot be used by applications.\n",
umip_insns[umip_inst]);
- /* Do not emulate SLDT, STR or user long mode processes. */
- if (umip_inst == UMIP_INST_STR || umip_inst == UMIP_INST_SLDT || user_64bit_mode(regs))
+ /* Do not emulate (spoof) SLDT or STR. */
+ if (umip_inst == UMIP_INST_STR || umip_inst == UMIP_INST_SLDT)
return false;
umip_pr_warning(regs, "For now, expensive software emulation returns the result.\n");
- if (emulate_umip_insn(&insn, umip_inst, dummy_data, &dummy_data_size))
+ if (emulate_umip_insn(&insn, umip_inst, dummy_data, &dummy_data_size,
+ user_64bit_mode(regs)))
return false;
/*
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 4fe1601..86976b5 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -33,7 +33,7 @@
102:
.section .fixup,"ax"
103: addl %ecx,%edx /* ecx is zerorest also */
- jmp copy_user_handle_tail
+ jmp .Lcopy_user_handle_tail
.previous
_ASM_EXTABLE_UA(100b, 103b)
@@ -113,7 +113,7 @@
40: leal (%rdx,%rcx,8),%edx
jmp 60f
50: movl %ecx,%edx
-60: jmp copy_user_handle_tail /* ecx is zerorest also */
+60: jmp .Lcopy_user_handle_tail /* ecx is zerorest also */
.previous
_ASM_EXTABLE_UA(1b, 30b)
@@ -177,7 +177,7 @@
.section .fixup,"ax"
11: leal (%rdx,%rcx,8),%ecx
12: movl %ecx,%edx /* ecx is zerorest also */
- jmp copy_user_handle_tail
+ jmp .Lcopy_user_handle_tail
.previous
_ASM_EXTABLE_UA(1b, 11b)
@@ -210,7 +210,7 @@
.section .fixup,"ax"
12: movl %ecx,%edx /* ecx is zerorest also */
- jmp copy_user_handle_tail
+ jmp .Lcopy_user_handle_tail
.previous
_ASM_EXTABLE_UA(1b, 12b)
@@ -231,7 +231,7 @@
* eax uncopied bytes or 0 if successful.
*/
ALIGN;
-copy_user_handle_tail:
+.Lcopy_user_handle_tail:
movl %edx,%ecx
1: rep movsb
2: mov %ecx,%eax
@@ -239,7 +239,7 @@
ret
_ASM_EXTABLE_UA(1b, 2b)
-END(copy_user_handle_tail)
+END(.Lcopy_user_handle_tail)
/*
* copy_user_nocache - Uncached memory copy with exception handling
@@ -364,7 +364,7 @@
movl %ecx,%edx
.L_fixup_handle_tail:
sfence
- jmp copy_user_handle_tail
+ jmp .Lcopy_user_handle_tail
.previous
_ASM_EXTABLE_UA(1b, .L_fixup_4x8b_copy)
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 304f958..9578eb8 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -115,7 +115,7 @@
EXPORT_SYMBOL(__get_user_8)
-bad_get_user_clac:
+.Lbad_get_user_clac:
ASM_CLAC
bad_get_user:
xor %edx,%edx
@@ -123,7 +123,7 @@
ret
#ifdef CONFIG_X86_32
-bad_get_user_8_clac:
+.Lbad_get_user_8_clac:
ASM_CLAC
bad_get_user_8:
xor %edx,%edx
@@ -132,12 +132,12 @@
ret
#endif
- _ASM_EXTABLE_UA(1b, bad_get_user_clac)
- _ASM_EXTABLE_UA(2b, bad_get_user_clac)
- _ASM_EXTABLE_UA(3b, bad_get_user_clac)
+ _ASM_EXTABLE_UA(1b, .Lbad_get_user_clac)
+ _ASM_EXTABLE_UA(2b, .Lbad_get_user_clac)
+ _ASM_EXTABLE_UA(3b, .Lbad_get_user_clac)
#ifdef CONFIG_X86_64
- _ASM_EXTABLE_UA(4b, bad_get_user_clac)
+ _ASM_EXTABLE_UA(4b, .Lbad_get_user_clac)
#else
- _ASM_EXTABLE_UA(4b, bad_get_user_8_clac)
- _ASM_EXTABLE_UA(5b, bad_get_user_8_clac)
+ _ASM_EXTABLE_UA(4b, .Lbad_get_user_8_clac)
+ _ASM_EXTABLE_UA(5b, .Lbad_get_user_8_clac)
#endif
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index 14bf783..126dd6a 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -37,7 +37,7 @@
ENTRY(__put_user_1)
ENTER
cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
- jae bad_put_user
+ jae .Lbad_put_user
ASM_STAC
1: movb %al,(%_ASM_CX)
xor %eax,%eax
@@ -51,7 +51,7 @@
mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
sub $1,%_ASM_BX
cmp %_ASM_BX,%_ASM_CX
- jae bad_put_user
+ jae .Lbad_put_user
ASM_STAC
2: movw %ax,(%_ASM_CX)
xor %eax,%eax
@@ -65,7 +65,7 @@
mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
sub $3,%_ASM_BX
cmp %_ASM_BX,%_ASM_CX
- jae bad_put_user
+ jae .Lbad_put_user
ASM_STAC
3: movl %eax,(%_ASM_CX)
xor %eax,%eax
@@ -79,7 +79,7 @@
mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
sub $7,%_ASM_BX
cmp %_ASM_BX,%_ASM_CX
- jae bad_put_user
+ jae .Lbad_put_user
ASM_STAC
4: mov %_ASM_AX,(%_ASM_CX)
#ifdef CONFIG_X86_32
@@ -91,16 +91,16 @@
ENDPROC(__put_user_8)
EXPORT_SYMBOL(__put_user_8)
-bad_put_user_clac:
+.Lbad_put_user_clac:
ASM_CLAC
-bad_put_user:
+.Lbad_put_user:
movl $-EFAULT,%eax
RET
- _ASM_EXTABLE_UA(1b, bad_put_user_clac)
- _ASM_EXTABLE_UA(2b, bad_put_user_clac)
- _ASM_EXTABLE_UA(3b, bad_put_user_clac)
- _ASM_EXTABLE_UA(4b, bad_put_user_clac)
+ _ASM_EXTABLE_UA(1b, .Lbad_put_user_clac)
+ _ASM_EXTABLE_UA(2b, .Lbad_put_user_clac)
+ _ASM_EXTABLE_UA(3b, .Lbad_put_user_clac)
+ _ASM_EXTABLE_UA(4b, .Lbad_put_user_clac)
#ifdef CONFIG_X86_32
- _ASM_EXTABLE_UA(5b, bad_put_user_clac)
+ _ASM_EXTABLE_UA(5b, .Lbad_put_user_clac)
#endif
