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-rw-r--r--arch/i386/Kconfig.debug10
-rw-r--r--arch/i386/kernel/alternative.c63
-rw-r--r--arch/i386/kernel/entry.S39
-rw-r--r--arch/i386/kernel/module.c11
-rw-r--r--arch/i386/kernel/paravirt.c44
-rw-r--r--arch/i386/kernel/vmlinux.lds.S6
-rw-r--r--include/asm-i386/alternative.h13
-rw-r--r--include/asm-i386/desc.h41
-rw-r--r--include/asm-i386/irqflags.h4
-rw-r--r--include/asm-i386/paravirt.h189
-rw-r--r--include/asm-i386/processor.h198
-rw-r--r--include/asm-i386/spinlock.h15
-rw-r--r--include/asm-x86_64/alternative.h12
-rw-r--r--scripts/mod/modpost.c2
14 files changed, 459 insertions, 188 deletions
diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug
index b31c0802e1cc..f68cc6f215f8 100644
--- a/arch/i386/Kconfig.debug
+++ b/arch/i386/Kconfig.debug
@@ -85,4 +85,14 @@ config DOUBLEFAULT
option saves about 4k and might cause you much additional grey
hair.
+config DEBUG_PARAVIRT
+ bool "Enable some paravirtualization debugging"
+ default y
+ depends on PARAVIRT && DEBUG_KERNEL
+ help
+ Currently deliberately clobbers regs which are allowed to be
+ clobbered in inlined paravirt hooks, even in native mode.
+ If turning this off solves a problem, then DISABLE_INTERRUPTS() or
+ ENABLE_INTERRUPTS() is lying about what registers can be clobbered.
+
endmenu
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 535f9794fba1..9eca21b49f6b 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -124,6 +124,20 @@ static unsigned char** find_nop_table(void)
#endif /* CONFIG_X86_64 */
+static void nop_out(void *insns, unsigned int len)
+{
+ unsigned char **noptable = find_nop_table();
+
+ while (len > 0) {
+ unsigned int noplen = len;
+ if (noplen > ASM_NOP_MAX)
+ noplen = ASM_NOP_MAX;
+ memcpy(insns, noptable[noplen], noplen);
+ insns += noplen;
+ len -= noplen;
+ }
+}
+
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
extern struct alt_instr __smp_alt_instructions[], __smp_alt_instructions_end[];
extern u8 *__smp_locks[], *__smp_locks_end[];
@@ -138,10 +152,9 @@ extern u8 __smp_alt_begin[], __smp_alt_end[];
void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
- unsigned char **noptable = find_nop_table();
struct alt_instr *a;
u8 *instr;
- int diff, i, k;
+ int diff;
DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end);
for (a = start; a < end; a++) {
@@ -159,13 +172,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
#endif
memcpy(instr, a->replacement, a->replacementlen);
diff = a->instrlen - a->replacementlen;
- /* Pad the rest with nops */
- for (i = a->replacementlen; diff > 0; diff -= k, i += k) {
- k = diff;
- if (k > ASM_NOP_MAX)
- k = ASM_NOP_MAX;
- memcpy(a->instr + i, noptable[k], k);
- }
+ nop_out(instr + a->replacementlen, diff);
}
}
@@ -209,7 +216,6 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end)
{
- unsigned char **noptable = find_nop_table();
u8 **ptr;
for (ptr = start; ptr < end; ptr++) {
@@ -217,7 +223,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
continue;
if (*ptr > text_end)
continue;
- **ptr = noptable[1][0];
+ nop_out(*ptr, 1);
};
}
@@ -343,6 +349,40 @@ void alternatives_smp_switch(int smp)
#endif
+#ifdef CONFIG_PARAVIRT
+void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
+{
+ struct paravirt_patch *p;
+
+ for (p = start; p < end; p++) {
+ unsigned int used;
+
+ used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr,
+ p->len);
+#ifdef CONFIG_DEBUG_PARAVIRT
+ {
+ int i;
+ /* Deliberately clobber regs using "not %reg" to find bugs. */
+ for (i = 0; i < 3; i++) {
+ if (p->len - used >= 2 && (p->clobbers & (1 << i))) {
+ memcpy(p->instr + used, "\xf7\xd0", 2);
+ p->instr[used+1] |= i;
+ used += 2;
+ }
+ }
+ }
+#endif
+ /* Pad the rest with nops */
+ nop_out(p->instr + used, p->len - used);
+ }
+
+ /* Sync to be conservative, in case we patched following instructions */
+ sync_core();
+}
+extern struct paravirt_patch __start_parainstructions[],
+ __stop_parainstructions[];
+#endif /* CONFIG_PARAVIRT */
+
void __init alternative_instructions(void)
{
unsigned long flags;
@@ -390,5 +430,6 @@ void __init alternative_instructions(void)
alternatives_smp_switch(0);
}
#endif
+ apply_paravirt(__start_parainstructions, __stop_parainstructions);
local_irq_restore(flags);
}
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index d274612e05cd..de34b7fed3c1 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -53,6 +53,19 @@
#include <asm/dwarf2.h>
#include "irq_vectors.h"
+/*
+ * We use macros for low-level operations which need to be overridden
+ * for paravirtualization. The following will never clobber any registers:
+ * INTERRUPT_RETURN (aka. "iret")
+ * GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
+ * ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
+ *
+ * For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
+ * specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
+ * Allowing a register to be clobbered can shrink the paravirt replacement
+ * enough to patch inline, increasing performance.
+ */
+
#define nr_syscalls ((syscall_table_size)/4)
CF_MASK = 0x00000001
@@ -63,9 +76,9 @@ NT_MASK = 0x00004000
VM_MASK = 0x00020000
#ifdef CONFIG_PREEMPT
-#define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF
+#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
#else
-#define preempt_stop
+#define preempt_stop(clobbers)
#define resume_kernel restore_nocheck
#endif
@@ -226,7 +239,7 @@ ENTRY(ret_from_fork)
ALIGN
RING0_PTREGS_FRAME
ret_from_exception:
- preempt_stop
+ preempt_stop(CLBR_ANY)
ret_from_intr:
GET_THREAD_INFO(%ebp)
check_userspace:
@@ -237,7 +250,7 @@ check_userspace:
jb resume_kernel # not returning to v8086 or userspace
ENTRY(resume_userspace)
- DISABLE_INTERRUPTS # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
movl TI_flags(%ebp), %ecx
@@ -248,7 +261,7 @@ ENTRY(resume_userspace)
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
- DISABLE_INTERRUPTS
+ DISABLE_INTERRUPTS(CLBR_ANY)
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_nocheck
need_resched:
@@ -277,7 +290,7 @@ sysenter_past_esp:
* No need to follow this irqs on/off section: the syscall
* disabled irqs and here we enable it straight after entry:
*/
- ENABLE_INTERRUPTS
+ ENABLE_INTERRUPTS(CLBR_NONE)
pushl $(__USER_DS)
CFI_ADJUST_CFA_OFFSET 4
/*CFI_REL_OFFSET ss, 0*/
@@ -322,7 +335,7 @@ sysenter_past_esp:
jae syscall_badsys
call *sys_call_table(,%eax,4)
movl %eax,PT_EAX(%esp)
- DISABLE_INTERRUPTS
+ DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX)
TRACE_IRQS_OFF
movl TI_flags(%ebp), %ecx
testw $_TIF_ALLWORK_MASK, %cx
@@ -364,7 +377,7 @@ syscall_call:
call *sys_call_table(,%eax,4)
movl %eax,PT_EAX(%esp) # store the return value
syscall_exit:
- DISABLE_INTERRUPTS # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
TRACE_IRQS_OFF
@@ -393,7 +406,7 @@ restore_nocheck_notrace:
.section .fixup,"ax"
iret_exc:
TRACE_IRQS_ON
- ENABLE_INTERRUPTS
+ ENABLE_INTERRUPTS(CLBR_NONE)
pushl $0 # no error code
pushl $do_iret_error
jmp error_code
@@ -436,7 +449,7 @@ ldt_ss:
CFI_ADJUST_CFA_OFFSET 4
pushl %eax
CFI_ADJUST_CFA_OFFSET 4
- DISABLE_INTERRUPTS
+ DISABLE_INTERRUPTS(CLBR_EAX)
TRACE_IRQS_OFF
lss (%esp), %esp
CFI_ADJUST_CFA_OFFSET -8
@@ -451,7 +464,7 @@ work_pending:
jz work_notifysig
work_resched:
call schedule
- DISABLE_INTERRUPTS # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
TRACE_IRQS_OFF
@@ -509,7 +522,7 @@ syscall_exit_work:
testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
jz work_pending
TRACE_IRQS_ON
- ENABLE_INTERRUPTS # could let do_syscall_trace() call
+ ENABLE_INTERRUPTS(CLBR_ANY) # could let do_syscall_trace() call
# schedule() instead
movl %esp, %eax
movl $1, %edx
@@ -693,7 +706,7 @@ ENTRY(device_not_available)
GET_CR0_INTO_EAX
testl $0x4, %eax # EM (math emulation bit)
jne device_not_available_emulate
- preempt_stop
+ preempt_stop(CLBR_ANY)
call math_state_restore
jmp ret_from_exception
device_not_available_emulate:
diff --git a/arch/i386/kernel/module.c b/arch/i386/kernel/module.c
index 470cf97e7cd3..d7d9c8b23f72 100644
--- a/arch/i386/kernel/module.c
+++ b/arch/i386/kernel/module.c
@@ -108,7 +108,8 @@ int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
- const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL;
+ const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
+ *para = NULL;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
@@ -118,6 +119,8 @@ int module_finalize(const Elf_Ehdr *hdr,
alt = s;
if (!strcmp(".smp_locks", secstrings + s->sh_name))
locks= s;
+ if (!strcmp(".parainstructions", secstrings + s->sh_name))
+ para = s;
}
if (alt) {
@@ -132,6 +135,12 @@ int module_finalize(const Elf_Ehdr *hdr,
lseg, lseg + locks->sh_size,
tseg, tseg + text->sh_size);
}
+
+ if (para) {
+ void *pseg = (void *)para->sh_addr;
+ apply_paravirt(pseg, pseg + para->sh_size);
+ }
+
return 0;
}
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c
index 478192cd4b90..d46460426446 100644
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -45,6 +45,49 @@ char *memory_setup(void)
return paravirt_ops.memory_setup();
}
+/* Simple instruction patching code. */
+#define DEF_NATIVE(name, code) \
+ extern const char start_##name[], end_##name[]; \
+ asm("start_" #name ": " code "; end_" #name ":")
+DEF_NATIVE(cli, "cli");
+DEF_NATIVE(sti, "sti");
+DEF_NATIVE(popf, "push %eax; popf");
+DEF_NATIVE(pushf, "pushf; pop %eax");
+DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
+DEF_NATIVE(iret, "iret");
+DEF_NATIVE(sti_sysexit, "sti; sysexit");
+
+static const struct native_insns
+{
+ const char *start, *end;
+} native_insns[] = {
+ [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli },
+ [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti },
+ [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf },
+ [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf },
+ [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli },
+ [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret },
+ [PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit },
+};
+
+static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
+{
+ unsigned int insn_len;
+
+ /* Don't touch it if we don't have a replacement */
+ if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start)
+ return len;
+
+ insn_len = native_insns[type].end - native_insns[type].start;
+
+ /* Similarly if we can't fit replacement. */
+ if (len < insn_len)
+ return len;
+
+ memcpy(insns, native_insns[type].start, insn_len);
+ return insn_len;
+}
+
static fastcall unsigned long native_get_debugreg(int regno)
{
unsigned long val = 0; /* Damn you, gcc! */
@@ -349,6 +392,7 @@ struct paravirt_ops paravirt_ops = {
.paravirt_enabled = 0,
.kernel_rpl = 0,
+ .patch = native_patch,
.banner = default_banner,
.arch_setup = native_nop,
.memory_setup = machine_specific_memory_setup,
diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S
index 6860f20aa579..5c69cf0e5944 100644
--- a/arch/i386/kernel/vmlinux.lds.S
+++ b/arch/i386/kernel/vmlinux.lds.S
@@ -165,6 +165,12 @@ SECTIONS
.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
*(.altinstr_replacement)
}
+ . = ALIGN(4);
+ __start_parainstructions = .;
+ .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
+ *(.parainstructions)
+ }
+ __stop_parainstructions = .;
/* .exit.text is discard at runtime, not link time, to deal with references
from .altinstructions and .eh_frame */
.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { *(.exit.text) }
diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h
index b01a7ec409ce..b8fa9557c532 100644
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -4,7 +4,7 @@
#ifdef __KERNEL__
#include <asm/types.h>
-
+#include <linux/stddef.h>
#include <linux/types.h>
struct alt_instr {
@@ -118,4 +118,15 @@ static inline void alternatives_smp_switch(int smp) {}
#define LOCK_PREFIX ""
#endif
+struct paravirt_patch;
+#ifdef CONFIG_PARAVIRT
+void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end);
+#else
+static inline void
+apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
+{}
+#define __start_parainstructions NULL
+#define __stop_parainstructions NULL
+#endif
+
#endif /* _I386_ALTERNATIVE_H */
diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h
index f19820f0834f..f398cc456448 100644
--- a/include/asm-i386/desc.h
+++ b/include/asm-i386/desc.h
@@ -81,31 +81,15 @@ static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
#undef C
}
-static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entry_b)
-{
- __u32 *lp = (__u32 *)((char *)dt + entry*8);
- *lp = entry_a;
- *(lp+1) = entry_b;
-}
-
#define write_ldt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
#define write_gdt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
#define write_idt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
-static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
-{
- __u32 a, b;
- pack_gate(&a, &b, (unsigned long)addr, seg, type, 0);
- write_idt_entry(idt_table, gate, a, b);
-}
-
-static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const void *addr)
+static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entry_b)
{
- __u32 a, b;
- pack_descriptor(&a, &b, (unsigned long)addr,
- offsetof(struct tss_struct, __cacheline_filler) - 1,
- DESCTYPE_TSS, 0);
- write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b);
+ __u32 *lp = (__u32 *)((char *)dt + entry*8);
+ *lp = entry_a;
+ *(lp+1) = entry_b;
}
#define set_ldt native_set_ldt
@@ -128,6 +112,23 @@ static inline fastcall void native_set_ldt(const void *addr,
}
}
+static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
+{
+ __u32 a, b;
+ pack_gate(&a, &b, (unsigned long)addr, seg, type, 0);
+ write_idt_entry(idt_table, gate, a, b);
+}
+
+static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const void *addr)
+{
+ __u32 a, b;
+ pack_descriptor(&a, &b, (unsigned long)addr,
+ offsetof(struct tss_struct, __cacheline_filler) - 1,
+ DESCTYPE_TSS, 0);
+ write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b);
+}
+
+
#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
#define LDT_entry_a(info) \
diff --git a/include/asm-i386/irqflags.h b/include/asm-i386/irqflags.h
index 9ce01f3fb7bc..17b18cf4fe9d 100644
--- a/include/asm-i386/irqflags.h
+++ b/include/asm-i386/irqflags.h
@@ -79,8 +79,8 @@ static inline unsigned long __raw_local_irq_save(void)
}
#else
-#define DISABLE_INTERRUPTS cli
-#define ENABLE_INTERRUPTS sti
+#define DISABLE_INTERRUPTS(clobbers) cli
+#define ENABLE_INTERRUPTS(clobbers) sti
#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
#define INTERRUPT_RETURN iret
#define GET_CR0_INTO_EAX movl %cr0, %eax
diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h
index a7551a44686f..081194751ade 100644
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -3,8 +3,26 @@
/* Various instructions on x86 need to be replaced for
* para-virtualization: those hooks are defined here. */
#include <linux/linkage.h>
+#include <linux/stringify.h>
#ifdef CONFIG_PARAVIRT
+/* These are the most performance critical ops, so we want to be able to patch
+ * callers */
+#define PARAVIRT_IRQ_DISABLE 0
+#define PARAVIRT_IRQ_ENABLE 1
+#define PARAVIRT_RESTORE_FLAGS 2
+#define PARAVIRT_SAVE_FLAGS 3
+#define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4
+#define PARAVIRT_INTERRUPT_RETURN 5
+#define PARAVIRT_STI_SYSEXIT 6
+
+/* Bitmask of what can be clobbered: usually at least eax. */
+#define CLBR_NONE 0x0
+#define CLBR_EAX 0x1
+#define CLBR_ECX 0x2
+#define CLBR_EDX 0x4
+#define CLBR_ANY 0x7
+
#ifndef __ASSEMBLY__
struct thread_struct;
struct Xgt_desc_struct;
@@ -15,6 +33,15 @@ struct paravirt_ops
int paravirt_enabled;
const char *name;
+ /*
+ * Patch may replace one of the defined code sequences with arbitrary
+ * code, subject to the same register constraints. This generally
+ * means the code is not free to clobber any registers other than EAX.
+ * The patch function should return the number of bytes of code
+ * generated, as we nop pad the rest in generic code.
+ */
+ unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len);
+
void (*arch_setup)(void);
char *(*memory_setup)(void);
void (*init_IRQ)(void);
@@ -147,35 +174,6 @@ static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
#define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
#define write_cr4(x) paravirt_ops.write_cr4(x)
-static inline unsigned long __raw_local_save_flags(void)
-{
- return paravirt_ops.save_fl();
-}
-
-static inline void raw_local_irq_restore(unsigned long flags)
-{
- return paravirt_ops.restore_fl(flags);
-}
-
-static inline void raw_local_irq_disable(void)
-{
- paravirt_ops.irq_disable();
-}
-
-static inline void raw_local_irq_enable(void)
-{
- paravirt_ops.irq_enable();
-}
-
-static inline unsigned long __raw_local_irq_save(void)
-{
- unsigned long flags = paravirt_ops.save_fl();
-
- paravirt_ops.irq_disable();
-
- return flags;
-}
-
static inline void raw_safe_halt(void)
{
paravirt_ops.safe_halt();
@@ -267,15 +265,134 @@ static inline void slow_down_io(void) {
#endif
}
-#define CLI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax"
-#define STI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax"
+/* These all sit in the .parainstructions section to tell us what to patch. */
+struct paravirt_patch {
+ u8 *instr; /* original instructions */
+ u8 instrtype; /* type of this instruction */
+ u8 len; /* length of original instruction */
+ u16 clobbers; /* what registers you may clobber */
+};
+
+#define paravirt_alt(insn_string, typenum, clobber) \
+ "771:\n\t" insn_string "\n" "772:\n" \
+ ".pushsection .parainstructions,\"a\"\n" \
+ " .long 771b\n" \
+ " .byte " __stringify(typenum) "\n" \
+ " .byte 772b-771b\n" \
+ " .short " __stringify(clobber) "\n" \
+ ".popsection"
+
+static inline unsigned long __raw_local_save_flags(void)
+{
+ unsigned long f;
+
+ __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
+ "call *%1;"
+ "popl %%edx; popl %%ecx",
+ PARAVIRT_SAVE_FLAGS, CLBR_NONE)
+ : "=a"(f): "m"(paravirt_ops.save_fl)
+ : "memory", "cc");
+ return f;
+}
+
+static inline void raw_local_irq_restore(unsigned long f)
+{
+ __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
+ "call *%1;"
+ "popl %%edx; popl %%ecx",
+ PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
+ : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
+ : "memory", "cc");
+}
+
+static inline void raw_local_irq_disable(void)
+{
+ __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
+ "call *%0;"
+ "popl %%edx; popl %%ecx",
+ PARAVIRT_IRQ_DISABLE, CLBR_EAX)
+ : : "m" (paravirt_ops.irq_disable)
+ : "memory", "eax", "cc");
+}
+
+static inline void raw_local_irq_enable(void)
+{
+ __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
+ "call *%0;"
+ "popl %%edx; popl %%ecx",
+ PARAVIRT_IRQ_ENABLE, CLBR_EAX)
+ : : "m" (paravirt_ops.irq_enable)
+ : "memory", "eax", "cc");
+}
+
+static inline unsigned long __raw_local_irq_save(void)
+{
+ unsigned long f;
+
+ __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
+ "call *%1; pushl %%eax;"
+ "call *%2; popl %%eax;"
+ "popl %%edx; popl %%ecx",
+ PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
+ CLBR_NONE)
+ : "=a"(f)
+ : "m" (paravirt_ops.save_fl),
+ "m" (paravirt_ops.irq_disable)
+ : "memory", "cc");
+ return f;
+}
+
+#define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;" \
+ "call *paravirt_ops+%c[irq_disable];" \
+ "popl %%edx; popl %%ecx", \
+ PARAVIRT_IRQ_DISABLE, CLBR_EAX)
+
+#define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;" \
+ "call *paravirt_ops+%c[irq_enable];" \
+ "popl %%edx; popl %%ecx", \
+ PARAVIRT_IRQ_ENABLE, CLBR_EAX)
+#define CLI_STI_CLOBBERS , "%eax"
+#define CLI_STI_INPUT_ARGS \
+ , \
+ [irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)), \
+ [irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
+
#else /* __ASSEMBLY__ */
-#define INTERRUPT_RETURN jmp *%cs:paravirt_ops+PARAVIRT_iret
-#define DISABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax
-#define ENABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *%cs:paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax
-#define ENABLE_INTERRUPTS_SYSEXIT jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit
-#define GET_CR0_INTO_EAX call *paravirt_ops+PARAVIRT_read_cr0
+#define PARA_PATCH(ptype, clobbers, ops) \
+771:; \
+ ops; \
+772:; \
+ .pushsection .parainstructions,"a"; \
+ .long 771b; \
+ .byte ptype; \
+ .byte 772b-771b; \
+ .short clobbers; \
+ .popsection
+
+#define INTERRUPT_RETURN \
+ PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \
+ jmp *%cs:paravirt_ops+PARAVIRT_iret)
+
+#define DISABLE_INTERRUPTS(clobbers) \
+ PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers, \
+ pushl %ecx; pushl %edx; \
+ call *paravirt_ops+PARAVIRT_irq_disable; \
+ popl %edx; popl %ecx) \
+
+#define ENABLE_INTERRUPTS(clobbers) \
+ PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers, \
+ pushl %ecx; pushl %edx; \
+ call *%cs:paravirt_ops+PARAVIRT_irq_enable; \
+ popl %edx; popl %ecx)
+
+#define ENABLE_INTERRUPTS_SYSEXIT \
+ PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY, \
+ jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
+
+#define GET_CR0_INTO_EAX \
+ call *paravirt_ops+PARAVIRT_read_cr0
+
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */
#endif /* __ASM_PARAVIRT_H */
diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 6c2c4457be0a..5f0418d0078c 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -156,59 +156,6 @@ static inline fastcall void native_cpuid(unsigned int *eax, unsigned int *ebx,
: "0" (*eax), "2" (*ecx));
}
-/*
- * Generic CPUID function
- * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
- * resulting in stale register contents being returned.
- */
-static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx)
-{
- *eax = op;
- *ecx = 0;
- __cpuid(eax, ebx, ecx, edx);
-}
-
-/* Some CPUID calls want 'count' to be placed in ecx */
-static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
- int *edx)
-{
- *eax = op;
- *ecx = count;
- __cpuid(eax, ebx, ecx, edx);
-}
-
-/*
- * CPUID functions returning a single datum
- */
-static inline unsigned int cpuid_eax(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
- return eax;
-}
-static inline unsigned int cpuid_ebx(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
- return ebx;
-}
-static inline unsigned int cpuid_ecx(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
- return ecx;
-}
-static inline unsigned int cpuid_edx(unsigned int op)
-{
- unsigned int eax, ebx, ecx, edx;
-
- cpuid(op, &eax, &ebx, &ecx, &edx);
- return edx;
-}
-
#define load_cr3(pgdir) write_cr3(__pa(pgdir))
/*
@@ -491,22 +438,6 @@ struct thread_struct {
.io_bitmap = { [ 0 ... IO_BITMAP_LONGS] = ~0 }, \
}
-#ifdef CONFIG_PARAVIRT
-#include <asm/paravirt.h>
-#else
-#define paravirt_enabled() 0
-#define __cpuid native_cpuid
-
-static inline void load_esp0(struct tss_struct *tss, struct thread_struct *thread)
-{
- tss->esp0 = thread->esp0;
- /* This can only happen when SEP is enabled, no need to test "SEP"arately */
- if (unlikely(tss->ss1 != thread->sysenter_cs)) {
- tss->ss1 = thread->sysenter_cs;
- wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
- }
-}
-
#define start_thread(regs, new_eip, new_esp) do { \
__asm__("movl %0,%%fs": :"r" (0)); \
regs->xgs = 0; \
@@ -519,36 +450,6 @@ static inline void load_esp0(struct tss_struct *tss, struct thread_struct *threa
regs->esp = new_esp; \
} while (0)
-/*
- * These special macros can be used to get or set a debugging register
- */
-#define get_debugreg(var, register) \
- __asm__("movl %%db" #register ", %0" \
- :"=r" (var))
-#define set_debugreg(value, register) \
- __asm__("movl %0,%%db" #register \
- : /* no output */ \
- :"r" (value))
-
-#define set_iopl_mask native_set_iopl_mask
-#endif /* CONFIG_PARAVIRT */
-
-/*
- * Set IOPL bits in EFLAGS from given mask
- */
-static fastcall inline void native_set_iopl_mask(unsigned mask)
-{
- unsigned int reg;
- __asm__ __volatile__ ("pushfl;"
- "popl %0;"
- "andl %1, %0;"
- "orl %2, %0;"
- "pushl %0;"
- "popfl"
- : "=&r" (reg)
- : "i" (~X86_EFLAGS_IOPL), "r" (mask));
-}
-
/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;
@@ -640,6 +541,105 @@ static inline void rep_nop(void)
#define cpu_relax() rep_nop()
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define paravirt_enabled() 0
+#define __cpuid native_cpuid
+
+static inline void load_esp0(struct tss_struct *tss, struct thread_struct *thread)
+{
+ tss->esp0 = thread->esp0;
+ /* This can only happen when SEP is enabled, no need to test "SEP"arately */
+ if (unlikely(tss->ss1 != thread->sysenter_cs)) {
+ tss->ss1 = thread->sysenter_cs;
+ wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
+ }
+}
+
+/*
+ * These special macros can be used to get or set a debugging register
+ */
+#define get_debugreg(var, register) \
+ __asm__("movl %%db" #register ", %0" \
+ :"=r" (var))
+#define set_debugreg(value, register) \
+ __asm__("movl %0,%%db" #register \
+ : /* no output */ \
+ :"r" (value))
+
+#define set_iopl_mask native_set_iopl_mask
+#endif /* CONFIG_PARAVIRT */
+
+/*
+ * Set IOPL bits in EFLAGS from given mask
+ */
+static fastcall inline void native_set_iopl_mask(unsigned mask)
+{
+ unsigned int reg;
+ __asm__ __volatile__ ("pushfl;"
+ "popl %0;"
+ "andl %1, %0;"
+ "orl %2, %0;"
+ "pushl %0;"
+ "popfl"
+ : "=&r" (reg)
+ : "i" (~X86_EFLAGS_IOPL), "r" (mask));
+}
+
+/*
+ * Generic CPUID function
+ * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
+ * resulting in stale register contents being returned.
+ */
+static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx)
+{
+ *eax = op;
+ *ecx = 0;
+ __cpuid(eax, ebx, ecx, edx);
+}
+
+/* Some CPUID calls want 'count' to be placed in ecx */
+static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
+ int *edx)
+{
+ *eax = op;
+ *ecx = count;
+ __cpuid(eax, ebx, ecx, edx);
+}
+
+/*
+ * CPUID functions returning a single datum
+ */
+static inline unsigned int cpuid_eax(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+ return eax;
+}
+static inline unsigned int cpuid_ebx(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+ return ebx;
+}
+static inline unsigned int cpuid_ecx(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+ return ecx;
+}
+static inline unsigned int cpuid_edx(unsigned int op)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
+ return edx;
+}
+
/* generic versions from gas */
#define GENERIC_NOP1 ".byte 0x90\n"
#define GENERIC_NOP2 ".byte 0x89,0xf6\n"
diff --git a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h
index dea60709db29..d3bcebed60ca 100644
--- a/include/asm-i386/spinlock.h
+++ b/include/asm-i386/spinlock.h
@@ -12,6 +12,8 @@
#else
#define CLI_STRING "cli"
#define STI_STRING "sti"
+#define CLI_STI_CLOBBERS
+#define CLI_STI_INPUT_ARGS
#endif /* CONFIG_PARAVIRT */
/*
@@ -57,25 +59,28 @@ static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long fla
{
asm volatile(
"\n1:\t"
- LOCK_PREFIX " ; decb %0\n\t"
+ LOCK_PREFIX " ; decb %[slock]\n\t"
"jns 5f\n"
"2:\t"
- "testl $0x200, %1\n\t"
+ "testl $0x200, %[flags]\n\t"
"jz 4f\n\t"
STI_STRING "\n"
"3:\t"
"rep;nop\n\t"
- "cmpb $0, %0\n\t"
+ "cmpb $0, %[slock]\n\t"
"jle 3b\n\t"
CLI_STRING "\n\t"
"jmp 1b\n"
"4:\t"
"rep;nop\n\t"
- "cmpb $0, %0\n\t"
+ "cmpb $0, %[slock]\n\t"
"jg 1b\n\t"
"jmp 4b\n"
"5:\n\t"
- : "+m" (lock->slock) : "r" (flags) : "memory");
+ : [slock] "+m" (lock->slock)
+ : [flags] "r" (flags)
+ CLI_STI_INPUT_ARGS
+ : "memory" CLI_STI_CLOBBERS);
}
#endif
diff --git a/include/asm-x86_64/alternative.h b/include/asm-x86_64/alternative.h
index a584826cc570..a6657b4f3e0e 100644
--- a/include/asm-x86_64/alternative.h
+++ b/include/asm-x86_64/alternative.h
@@ -4,6 +4,7 @@
#ifdef __KERNEL__
#include <linux/types.h>
+#include <linux/stddef.h>
#include <asm/cpufeature.h>
struct alt_instr {
@@ -133,4 +134,15 @@ static inline void alternatives_smp_switch(int smp) {}
#define LOCK_PREFIX ""
#endif
+struct paravirt_patch;
+#ifdef CONFIG_PARAVIRT
+void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end);
+#else
+static inline void
+apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
+{}
+#define __start_parainstructions NULL
+#define __stop_parainstructions NULL
+#endif
+
#endif /* _X86_64_ALTERNATIVE_H */
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 2e1141623147..ac0a58222992 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -911,6 +911,7 @@ static int init_section_ref_ok(const char *name)
".toc1", /* used by ppc64 */
".stab",
".rodata",
+ ".parainstructions",
".text.lock",
"__bug_table", /* used by powerpc for BUG() */
".pci_fixup_header",
@@ -931,6 +932,7 @@ static int init_section_ref_ok(const char *name)
".altinstructions",
".eh_frame",
".debug",
+ ".parainstructions",
NULL
};
/* part of section name */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.