diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug index b31c0802e1ccf53f1e5a677e802c5e34166ebc54..f68cc6f215f8b1c9bff53c0f6668d4b792f3b30a 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 535f9794fba1aa811cb7a1ea270fa3c285fc0f98..9eca21b49f6b3d0487df153594cdcbbfdebc17c7 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 d274612e05cdbde1e2190d43646878551042d737..de34b7fed3c1718d88886fa3e24a94fa49ac662f 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -53,6 +53,19 @@ #include #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 470cf97e7cd3104bbfd6eb2de379d0bd0be9c460..d7d9c8b23f72782f7798340678a41536b7dd64e6 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 478192cd4b90db06fb48d908252f7dc601f643b3..d46460426446bc1756d102b05b76e2a7f0b52d5f 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 6860f20aa5791c8a67483d3313118dc5f6e88624..5c69cf0e5944a41a8f1421a34d617004c86550d4 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 b01a7ec409ced2397bc8529051930dd4e3413b67..b8fa9557c532ffdebcfa6324a2b3d722514e336f 100644 --- a/include/asm-i386/alternative.h +++ b/include/asm-i386/alternative.h @@ -4,7 +4,7 @@ #ifdef __KERNEL__ #include - +#include #include 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 f19820f0834f8c0beece9407fd988a25edcf3bb4..f398cc456448187bff38c53ad81a314d2d063212 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 9ce01f3fb7bcb4c98171610cd06cdf45e8a23a8c..17b18cf4fe9dc6bc5fb31bca36b55c144cd954e6 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 a7551a44686ffbe600c44714578827d90f6f622d..081194751ade25bfe2d025894a3650779f41a49b 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 +#include #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 6c2c4457be0aa2f1529edcae6a216d41dfe89ec0..5f0418d0078c893a7a896dcb75dedb30dd1bace3 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 -#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 +#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 dea60709db29fe233285e01a1e733739bf98bd5a..d3bcebed60ca6ef4895b7a22ea139023f4a6d49f 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 a584826cc570f6aa6415b62d255a789feb8b22a6..a6657b4f3e0eccc7660983382c378b67813d16d3 100644 --- a/include/asm-x86_64/alternative.h +++ b/include/asm-x86_64/alternative.h @@ -4,6 +4,7 @@ #ifdef __KERNEL__ #include +#include #include 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 2e1141623147887ffa2f91bb6e53b362a0a5f821..ac0a582229924d3d65d7903724fe2900a424088a 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 */