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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-01 21:24:43 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-01 21:24:43 +0100 |
commit | 43aa0a195f06101bcb5d8d711bba0dd24b33a1a0 (patch) | |
tree | 0236661db875f519cc80e11fde210fdfc9b2be76 /arch/x86 | |
parent | Merge tag 'locking-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/ker... (diff) | |
parent | bpf,x86: Respect X86_FEATURE_RETPOLINE* (diff) | |
download | linux-43aa0a195f06101bcb5d8d711bba0dd24b33a1a0.tar.xz linux-43aa0a195f06101bcb5d8d711bba0dd24b33a1a0.zip |
Merge tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Thomas Gleixner:
- Improve retpoline code patching by separating it from alternatives
which reduces memory footprint and allows to do better optimizations
in the actual runtime patching.
- Add proper retpoline support for x86/BPF
- Address noinstr warnings in x86/kvm, lockdep and paravirtualization
code
- Add support to handle pv_opsindirect calls in the noinstr analysis
- Classify symbols upfront and cache the result to avoid redundant
str*cmp() invocations.
- Add a CFI hash to reduce memory consumption which also reduces
runtime on a allyesconfig by ~50%
- Adjust XEN code to make objtool handling more robust and as a side
effect to prevent text fragmentation due to placement of the
hypercall page.
* tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
bpf,x86: Respect X86_FEATURE_RETPOLINE*
bpf,x86: Simplify computing label offsets
x86,bugs: Unconditionally allow spectre_v2=retpoline,amd
x86/alternative: Add debug prints to apply_retpolines()
x86/alternative: Try inline spectre_v2=retpoline,amd
x86/alternative: Handle Jcc __x86_indirect_thunk_\reg
x86/alternative: Implement .retpoline_sites support
x86/retpoline: Create a retpoline thunk array
x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h
x86/asm: Fixup odd GEN-for-each-reg.h usage
x86/asm: Fix register order
x86/retpoline: Remove unused replacement symbols
objtool,x86: Replace alternatives with .retpoline_sites
objtool: Shrink struct instruction
objtool: Explicitly avoid self modifying code in .altinstr_replacement
objtool: Classify symbols
objtool: Support pv_opsindirect calls for noinstr
x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays
x86/xen: Mark xen_force_evtchn_callback() noinstr
x86/xen: Make irq_disable() noinstr
...
Diffstat (limited to 'arch/x86')
25 files changed, 546 insertions, 429 deletions
diff --git a/arch/x86/include/asm/GEN-for-each-reg.h b/arch/x86/include/asm/GEN-for-each-reg.h index 1b07fb102c4e..07949102a08d 100644 --- a/arch/x86/include/asm/GEN-for-each-reg.h +++ b/arch/x86/include/asm/GEN-for-each-reg.h @@ -1,11 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * These are in machine order; things rely on that. + */ #ifdef CONFIG_64BIT GEN(rax) -GEN(rbx) GEN(rcx) GEN(rdx) +GEN(rbx) +GEN(rsp) +GEN(rbp) GEN(rsi) GEN(rdi) -GEN(rbp) GEN(r8) GEN(r9) GEN(r10) @@ -16,10 +21,11 @@ GEN(r14) GEN(r15) #else GEN(eax) -GEN(ebx) GEN(ecx) GEN(edx) +GEN(ebx) +GEN(esp) +GEN(ebp) GEN(esi) GEN(edi) -GEN(ebp) #endif diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index a3c2315aca12..58eee6402832 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -75,6 +75,7 @@ extern int alternatives_patched; extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); +extern void apply_retpolines(s32 *start, s32 *end); struct module; diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h index 4cb726c71ed8..8f80de627c60 100644 --- a/arch/x86/include/asm/asm-prototypes.h +++ b/arch/x86/include/asm/asm-prototypes.h @@ -17,21 +17,3 @@ extern void cmpxchg8b_emu(void); #endif -#ifdef CONFIG_RETPOLINE - -#undef GEN -#define GEN(reg) \ - extern asmlinkage void __x86_indirect_thunk_ ## reg (void); -#include <asm/GEN-for-each-reg.h> - -#undef GEN -#define GEN(reg) \ - extern asmlinkage void __x86_indirect_alt_call_ ## reg (void); -#include <asm/GEN-for-each-reg.h> - -#undef GEN -#define GEN(reg) \ - extern asmlinkage void __x86_indirect_alt_jmp_ ## reg (void); -#include <asm/GEN-for-each-reg.h> - -#endif /* CONFIG_RETPOLINE */ diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index ec2d5c8c6694..cc74dc584836 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -5,12 +5,15 @@ #include <linux/static_key.h> #include <linux/objtool.h> +#include <linux/linkage.h> #include <asm/alternative.h> #include <asm/cpufeatures.h> #include <asm/msr-index.h> #include <asm/unwind_hints.h> +#define RETPOLINE_THUNK_SIZE 32 + /* * Fill the CPU return stack buffer. * @@ -118,6 +121,16 @@ ".popsection\n\t" #ifdef CONFIG_RETPOLINE + +typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE]; + +#define GEN(reg) \ + extern retpoline_thunk_t __x86_indirect_thunk_ ## reg; +#include <asm/GEN-for-each-reg.h> +#undef GEN + +extern retpoline_thunk_t __x86_indirect_thunk_array[]; + #ifdef CONFIG_X86_64 /* @@ -303,63 +316,4 @@ static inline void mds_idle_clear_cpu_buffers(void) #endif /* __ASSEMBLY__ */ -/* - * Below is used in the eBPF JIT compiler and emits the byte sequence - * for the following assembly: - * - * With retpolines configured: - * - * callq do_rop - * spec_trap: - * pause - * lfence - * jmp spec_trap - * do_rop: - * mov %rcx,(%rsp) for x86_64 - * mov %edx,(%esp) for x86_32 - * retq - * - * Without retpolines configured: - * - * jmp *%rcx for x86_64 - * jmp *%edx for x86_32 - */ -#ifdef CONFIG_RETPOLINE -# ifdef CONFIG_X86_64 -# define RETPOLINE_RCX_BPF_JIT_SIZE 17 -# define RETPOLINE_RCX_BPF_JIT() \ -do { \ - EMIT1_off32(0xE8, 7); /* callq do_rop */ \ - /* spec_trap: */ \ - EMIT2(0xF3, 0x90); /* pause */ \ - EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \ - EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \ - /* do_rop: */ \ - EMIT4(0x48, 0x89, 0x0C, 0x24); /* mov %rcx,(%rsp) */ \ - EMIT1(0xC3); /* retq */ \ -} while (0) -# else /* !CONFIG_X86_64 */ -# define RETPOLINE_EDX_BPF_JIT() \ -do { \ - EMIT1_off32(0xE8, 7); /* call do_rop */ \ - /* spec_trap: */ \ - EMIT2(0xF3, 0x90); /* pause */ \ - EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \ - EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \ - /* do_rop: */ \ - EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */ \ - EMIT1(0xC3); /* ret */ \ -} while (0) -# endif -#else /* !CONFIG_RETPOLINE */ -# ifdef CONFIG_X86_64 -# define RETPOLINE_RCX_BPF_JIT_SIZE 2 -# define RETPOLINE_RCX_BPF_JIT() \ - EMIT2(0xFF, 0xE1); /* jmp *%rcx */ -# else /* !CONFIG_X86_64 */ -# define RETPOLINE_EDX_BPF_JIT() \ - EMIT2(0xFF, 0xE2) /* jmp *%edx */ -# endif -#endif - #endif /* _ASM_X86_NOSPEC_BRANCH_H_ */ diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index da3a1ac82be5..cebec95a7124 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -52,11 +52,11 @@ void __init paravirt_set_cap(void); /* The paravirtualized I/O functions */ static inline void slow_down_io(void) { - pv_ops.cpu.io_delay(); + PVOP_VCALL0(cpu.io_delay); #ifdef REALLY_SLOW_IO - pv_ops.cpu.io_delay(); - pv_ops.cpu.io_delay(); - pv_ops.cpu.io_delay(); + PVOP_VCALL0(cpu.io_delay); + PVOP_VCALL0(cpu.io_delay); + PVOP_VCALL0(cpu.io_delay); #endif } @@ -113,12 +113,12 @@ static inline void __cpuid(unsigned int *eax, unsigned int *ebx, /* * These special macros can be used to get or set a debugging register */ -static inline unsigned long paravirt_get_debugreg(int reg) +static __always_inline unsigned long paravirt_get_debugreg(int reg) { return PVOP_CALL1(unsigned long, cpu.get_debugreg, reg); } #define get_debugreg(var, reg) var = paravirt_get_debugreg(reg) -static inline void set_debugreg(unsigned long val, int reg) +static __always_inline void set_debugreg(unsigned long val, int reg) { PVOP_VCALL2(cpu.set_debugreg, reg, val); } @@ -133,14 +133,14 @@ static inline void write_cr0(unsigned long x) PVOP_VCALL1(cpu.write_cr0, x); } -static inline unsigned long read_cr2(void) +static __always_inline unsigned long read_cr2(void) { return PVOP_ALT_CALLEE0(unsigned long, mmu.read_cr2, "mov %%cr2, %%rax;", ALT_NOT(X86_FEATURE_XENPV)); } -static inline void write_cr2(unsigned long x) +static __always_inline void write_cr2(unsigned long x) { PVOP_VCALL1(mmu.write_cr2, x); } @@ -653,10 +653,10 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu); * functions. */ #define PV_THUNK_NAME(func) "__raw_callee_save_" #func -#define PV_CALLEE_SAVE_REGS_THUNK(func) \ +#define __PV_CALLEE_SAVE_REGS_THUNK(func, section) \ extern typeof(func) __raw_callee_save_##func; \ \ - asm(".pushsection .text;" \ + asm(".pushsection " section ", \"ax\";" \ ".globl " PV_THUNK_NAME(func) ";" \ ".type " PV_THUNK_NAME(func) ", @function;" \ PV_THUNK_NAME(func) ":" \ @@ -669,6 +669,9 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu); ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";" \ ".popsection") +#define PV_CALLEE_SAVE_REGS_THUNK(func) \ + __PV_CALLEE_SAVE_REGS_THUNK(func, ".text") + /* Get a reference to a callee-save function */ #define PV_CALLEE_SAVE(func) \ ((struct paravirt_callee_save) { __raw_callee_save_##func }) @@ -678,23 +681,23 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu); ((struct paravirt_callee_save) { func }) #ifdef CONFIG_PARAVIRT_XXL -static inline notrace unsigned long arch_local_save_flags(void) +static __always_inline unsigned long arch_local_save_flags(void) { return PVOP_ALT_CALLEE0(unsigned long, irq.save_fl, "pushf; pop %%rax;", ALT_NOT(X86_FEATURE_XENPV)); } -static inline notrace void arch_local_irq_disable(void) +static __always_inline void arch_local_irq_disable(void) { PVOP_ALT_VCALLEE0(irq.irq_disable, "cli;", ALT_NOT(X86_FEATURE_XENPV)); } -static inline notrace void arch_local_irq_enable(void) +static __always_inline void arch_local_irq_enable(void) { PVOP_ALT_VCALLEE0(irq.irq_enable, "sti;", ALT_NOT(X86_FEATURE_XENPV)); } -static inline notrace unsigned long arch_local_irq_save(void) +static __always_inline unsigned long arch_local_irq_save(void) { unsigned long f; diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index b94f615600d5..703663175a5a 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -181,7 +181,7 @@ static inline bool any_64bit_mode(struct pt_regs *regs) #define current_user_stack_pointer() current_pt_regs()->sp #define compat_user_stack_pointer() current_pt_regs()->sp -static inline bool ip_within_syscall_gap(struct pt_regs *regs) +static __always_inline bool ip_within_syscall_gap(struct pt_regs *regs) { bool ret = (regs->ip >= (unsigned long)entry_SYSCALL_64 && regs->ip < (unsigned long)entry_SYSCALL_64_safe_stack); diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index 454b20815f35..4a7ff8b0db20 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -308,13 +308,13 @@ HYPERVISOR_platform_op(struct xen_platform_op *op) return _hypercall1(int, platform_op, op); } -static inline int +static __always_inline int HYPERVISOR_set_debugreg(int reg, unsigned long value) { return _hypercall2(int, set_debugreg, reg, value); } -static inline unsigned long +static __always_inline unsigned long HYPERVISOR_get_debugreg(int reg) { return _hypercall1(unsigned long, get_debugreg, reg); @@ -358,7 +358,7 @@ HYPERVISOR_event_channel_op(int cmd, void *arg) return _hypercall2(int, event_channel_op, cmd, arg); } -static inline int +static __always_inline int HYPERVISOR_xen_version(int cmd, void *arg) { return _hypercall2(int, xen_version, cmd, arg); diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index e9da3dc71254..23fb4d51a5da 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -29,6 +29,7 @@ #include <asm/io.h> #include <asm/fixmap.h> #include <asm/paravirt.h> +#include <asm/asm-prototypes.h> int __read_mostly alternatives_patched; @@ -113,6 +114,7 @@ static void __init_or_module add_nops(void *insns, unsigned int len) } } +extern s32 __retpoline_sites[], __retpoline_sites_end[]; extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; extern s32 __smp_locks[], __smp_locks_end[]; void text_poke_early(void *addr, const void *opcode, size_t len); @@ -221,7 +223,7 @@ static __always_inline int optimize_nops_range(u8 *instr, u8 instrlen, int off) * "noinline" to cause control flow change and thus invalidate I$ and * cause refetch after modification. */ -static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *instr) +static void __init_or_module noinline optimize_nops(u8 *instr, size_t len) { struct insn insn; int i = 0; @@ -239,11 +241,11 @@ static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *ins * optimized. */ if (insn.length == 1 && insn.opcode.bytes[0] == 0x90) - i += optimize_nops_range(instr, a->instrlen, i); + i += optimize_nops_range(instr, len, i); else i += insn.length; - if (i >= a->instrlen) + if (i >= len) return; } } @@ -331,10 +333,185 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, text_poke_early(instr, insn_buff, insn_buff_sz); next: - optimize_nops(a, instr); + optimize_nops(instr, a->instrlen); } } +#if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION) + +/* + * CALL/JMP *%\reg + */ +static int emit_indirect(int op, int reg, u8 *bytes) +{ + int i = 0; + u8 modrm; + + switch (op) { + case CALL_INSN_OPCODE: + modrm = 0x10; /* Reg = 2; CALL r/m */ + break; + + case JMP32_INSN_OPCODE: + modrm = 0x20; /* Reg = 4; JMP r/m */ + break; + + default: + WARN_ON_ONCE(1); + return -1; + } + + if (reg >= 8) { + bytes[i++] = 0x41; /* REX.B prefix */ + reg -= 8; + } + + modrm |= 0xc0; /* Mod = 3 */ + modrm += reg; + + bytes[i++] = 0xff; /* opcode */ + bytes[i++] = modrm; + + return i; +} + +/* + * Rewrite the compiler generated retpoline thunk calls. + * + * For spectre_v2=off (!X86_FEATURE_RETPOLINE), rewrite them into immediate + * indirect instructions, avoiding the extra indirection. + * + * For example, convert: + * + * CALL __x86_indirect_thunk_\reg + * + * into: + * + * CALL *%\reg + * + * It also tries to inline spectre_v2=retpoline,amd when size permits. + */ +static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes) +{ + retpoline_thunk_t *target; + int reg, ret, i = 0; + u8 op, cc; + + target = addr + insn->length + insn->immediate.value; + reg = target - __x86_indirect_thunk_array; + + if (WARN_ON_ONCE(reg & ~0xf)) + return -1; + + /* If anyone ever does: CALL/JMP *%rsp, we're in deep trouble. */ + BUG_ON(reg == 4); + + if (cpu_feature_enabled(X86_FEATURE_RETPOLINE) && + !cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) + return -1; + + op = insn->opcode.bytes[0]; + + /* + * Convert: + * + * Jcc.d32 __x86_indirect_thunk_\reg + * + * into: + * + * Jncc.d8 1f + * [ LFENCE ] + * JMP *%\reg + * [ NOP ] + * 1: + */ + /* Jcc.d32 second opcode byte is in the range: 0x80-0x8f */ + if (op == 0x0f && (insn->opcode.bytes[1] & 0xf0) == 0x80) { + cc = insn->opcode.bytes[1] & 0xf; + cc ^= 1; /* invert condition */ + + bytes[i++] = 0x70 + cc; /* Jcc.d8 */ + bytes[i++] = insn->length - 2; /* sizeof(Jcc.d8) == 2 */ + + /* Continue as if: JMP.d32 __x86_indirect_thunk_\reg */ + op = JMP32_INSN_OPCODE; + } + + /* + * For RETPOLINE_AMD: prepend the indirect CALL/JMP with an LFENCE. + */ + if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) { + bytes[i++] = 0x0f; + bytes[i++] = 0xae; + bytes[i++] = 0xe8; /* LFENCE */ + } + + ret = emit_indirect(op, reg, bytes + i); + if (ret < 0) + return ret; + i += ret; + + for (; i < insn->length;) + bytes[i++] = BYTES_NOP1; + + return i; +} + +/* + * Generated by 'objtool --retpoline'. + */ +void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) +{ + s32 *s; + + for (s = start; s < end; s++) { + void *addr = (void *)s + *s; + struct insn insn; + int len, ret; + u8 bytes[16]; + u8 op1, op2; + + ret = insn_decode_kernel(&insn, addr); + if (WARN_ON_ONCE(ret < 0)) + continue; + + op1 = insn.opcode.bytes[0]; + op2 = insn.opcode.bytes[1]; + + switch (op1) { + case CALL_INSN_OPCODE: + case JMP32_INSN_OPCODE: + break; + + case 0x0f: /* escape */ + if (op2 >= 0x80 && op2 <= 0x8f) + break; + fallthrough; + default: + WARN_ON_ONCE(1); + continue; + } + + DPRINTK("retpoline at: %pS (%px) len: %d to: %pS", + addr, addr, insn.length, + addr + insn.length + insn.immediate.value); + + len = patch_retpoline(addr, &insn, bytes); + if (len == insn.length) { + optimize_nops(bytes, len); + DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr); + DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr); + text_poke_early(addr, bytes, len); + } + } +} + +#else /* !RETPOLINES || !CONFIG_STACK_VALIDATION */ + +void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { } + +#endif /* CONFIG_RETPOLINE && CONFIG_STACK_VALIDATION */ + #ifdef CONFIG_SMP static void alternatives_smp_lock(const s32 *start, const s32 *end, u8 *text, u8 *text_end) @@ -643,6 +820,12 @@ void __init alternative_instructions(void) apply_paravirt(__parainstructions, __parainstructions_end); /* + * Rewrite the retpolines, must be done before alternatives since + * those can rewrite the retpoline thunks. + */ + apply_retpolines(__retpoline_sites, __retpoline_sites_end); + + /* * Then patch alternatives, such that those paravirt calls that are in * alternatives can be overwritten by their immediate fragments. */ diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index ecfca3bbcd96..ba43597f1027 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -882,13 +882,6 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void) return SPECTRE_V2_CMD_AUTO; } - if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD && - boot_cpu_data.x86_vendor != X86_VENDOR_HYGON && - boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { - pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n"); - return SPECTRE_V2_CMD_AUTO; - } - spec_v2_print_cond(mitigation_options[i].option, mitigation_options[i].secure); return cmd; diff --git a/arch/x86/kernel/irqflags.S b/arch/x86/kernel/irqflags.S index 8ef35063964b..760e1f293093 100644 --- a/arch/x86/kernel/irqflags.S +++ b/arch/x86/kernel/irqflags.S @@ -7,9 +7,11 @@ /* * unsigned long native_save_fl(void) */ +.pushsection .noinstr.text, "ax" SYM_FUNC_START(native_save_fl) pushf pop %_ASM_AX ret SYM_FUNC_END(native_save_fl) +.popsection EXPORT_SYMBOL(native_save_fl) diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index 5e9a34b5bd74..169fb6f4cd2e 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -251,7 +251,8 @@ int module_finalize(const Elf_Ehdr *hdr, struct module *me) { const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL, - *para = NULL, *orc = NULL, *orc_ip = NULL; + *para = NULL, *orc = NULL, *orc_ip = NULL, + *retpolines = NULL; char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { @@ -267,8 +268,14 @@ int module_finalize(const Elf_Ehdr *hdr, orc = s; if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name)) orc_ip = s; + if (!strcmp(".retpoline_sites", secstrings + s->sh_name)) + retpolines = s; } + if (retpolines) { + void *rseg = (void *)retpolines->sh_addr; + apply_retpolines(rseg, rseg + retpolines->sh_size); + } if (alt) { /* patch .altinstructions */ void *aseg = (void *)alt->sh_addr; diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 04cafc057bed..ebc45360ffd4 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -218,6 +218,36 @@ void paravirt_end_context_switch(struct task_struct *next) if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES)) arch_enter_lazy_mmu_mode(); } + +static noinstr unsigned long pv_native_read_cr2(void) +{ + return native_read_cr2(); +} + +static noinstr void pv_native_write_cr2(unsigned long val) +{ + native_write_cr2(val); +} + +static noinstr unsigned long pv_native_get_debugreg(int regno) +{ + return native_get_debugreg(regno); +} + +static noinstr void pv_native_set_debugreg(int regno, unsigned long val) +{ + native_set_debugreg(regno, val); +} + +static noinstr void pv_native_irq_enable(void) +{ + native_irq_enable(); +} + +static noinstr void pv_native_irq_disable(void) +{ + native_irq_disable(); +} #endif enum paravirt_lazy_mode paravirt_get_lazy_mode(void) @@ -244,8 +274,8 @@ struct paravirt_patch_template pv_ops = { #ifdef CONFIG_PARAVIRT_XXL .cpu.cpuid = native_cpuid, - .cpu.get_debugreg = native_get_debugreg, - .cpu.set_debugreg = native_set_debugreg, + .cpu.get_debugreg = pv_native_get_debugreg, + .cpu.set_debugreg = pv_native_set_debugreg, .cpu.read_cr0 = native_read_cr0, .cpu.write_cr0 = native_write_cr0, .cpu.write_cr4 = native_write_cr4, @@ -281,8 +311,8 @@ struct paravirt_patch_template pv_ops = { /* Irq ops. */ .irq.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl), - .irq.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable), - .irq.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable), + .irq.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable), + .irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_native_irq_enable), .irq.safe_halt = native_safe_halt, .irq.halt = native_halt, #endif /* CONFIG_PARAVIRT_XXL */ @@ -298,8 +328,8 @@ struct paravirt_patch_template pv_ops = { .mmu.exit_mmap = paravirt_nop, #ifdef CONFIG_PARAVIRT_XXL - .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2), - .mmu.write_cr2 = native_write_cr2, + .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(pv_native_read_cr2), + .mmu.write_cr2 = pv_native_write_cr2, .mmu.read_cr3 = __native_read_cr3, .mmu.write_cr3 = native_write_cr3, @@ -371,9 +401,6 @@ struct paravirt_patch_template pv_ops = { }; #ifdef CONFIG_PARAVIRT_XXL -/* At this point, native_get/set_debugreg has real function entries */ -NOKPROBE_SYMBOL(native_get_debugreg); -NOKPROBE_SYMBOL(native_set_debugreg); NOKPROBE_SYMBOL(native_load_idt); void (*paravirt_iret)(void) = native_iret; diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index bf1033a62e48..ff1e82ff52d9 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -64,7 +64,7 @@ static bool sev_es_negotiate_protocol(void) static __always_inline void vc_ghcb_invalidate(struct ghcb *ghcb) { ghcb->save.sw_exit_code = 0; - memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap)); + __builtin_memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap)); } static bool vc_decoding_needed(unsigned long exit_code) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index efd9e9ea17f2..3d6dc12d198f 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -272,6 +272,20 @@ SECTIONS __parainstructions_end = .; } +#ifdef CONFIG_RETPOLINE + /* + * List of instructions that call/jmp/jcc to retpoline thunks + * __x86_indirect_thunk_*(). These instructions can be patched along + * with alternatives, after which the section can be freed. + */ + . = ALIGN(8); + .retpoline_sites : AT(ADDR(.retpoline_sites) - LOAD_OFFSET) { + __retpoline_sites = .; + *(.retpoline_sites) + __retpoline_sites_end = .; + } +#endif + /* * struct alt_inst entries. From the header (alternative.h): * "Alternative instructions for different CPU types or capabilities" diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 5d30db599e10..e63ac08115cf 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -218,12 +218,12 @@ DECLARE_PER_CPU(struct svm_cpu_data *, svm_data); void recalc_intercepts(struct vcpu_svm *svm); -static inline struct kvm_svm *to_kvm_svm(struct kvm *kvm) +static __always_inline struct kvm_svm *to_kvm_svm(struct kvm *kvm) { return container_of(kvm, struct kvm_svm, kvm); } -static inline bool sev_guest(struct kvm *kvm) +static __always_inline bool sev_guest(struct kvm *kvm) { #ifdef CONFIG_KVM_AMD_SEV struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; @@ -234,7 +234,7 @@ static inline bool sev_guest(struct kvm *kvm) #endif } -static inline bool sev_es_guest(struct kvm *kvm) +static __always_inline bool sev_es_guest(struct kvm *kvm) { #ifdef CONFIG_KVM_AMD_SEV struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; @@ -271,7 +271,7 @@ static inline bool vmcb_is_dirty(struct vmcb *vmcb, int bit) return !test_bit(bit, (unsigned long *)&vmcb->control.clean); } -static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu) +static __always_inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu) { return container_of(vcpu, struct vcpu_svm, vcpu); } diff --git a/arch/x86/kvm/svm/svm_ops.h b/arch/x86/kvm/svm/svm_ops.h index 22e2b019de37..9430d6437c9f 100644 --- a/arch/x86/kvm/svm/svm_ops.h +++ b/arch/x86/kvm/svm/svm_ops.h @@ -56,12 +56,12 @@ static inline void invlpga(unsigned long addr, u32 asid) * VMSAVE, VMLOAD, etc... is still controlled by the effective address size, * hence 'unsigned long' instead of 'hpa_t'. */ -static inline void vmsave(unsigned long pa) +static __always_inline void vmsave(unsigned long pa) { svm_asm1(vmsave, "a" (pa), "memory"); } -static inline void vmload(unsigned long pa) +static __always_inline void vmload(unsigned long pa) { svm_asm1(vmload, "a" (pa), "memory"); } diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h index 152ab0aa82cf..16731d2cf231 100644 --- a/arch/x86/kvm/vmx/evmcs.h +++ b/arch/x86/kvm/vmx/evmcs.h @@ -93,7 +93,7 @@ static __always_inline int get_evmcs_offset(unsigned long field, return evmcs_field->offset; } -static inline void evmcs_write64(unsigned long field, u64 value) +static __always_inline void evmcs_write64(unsigned long field, u64 value) { u16 clean_field; int offset = get_evmcs_offset(field, &clean_field); @@ -183,7 +183,7 @@ static inline void evmcs_load(u64 phys_addr) __init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf); #else /* !IS_ENABLED(CONFIG_HYPERV) */ -static inline void evmcs_write64(unsigned long field, u64 value) {} +static __always_inline void evmcs_write64(unsigned long field, u64 value) {} static inline void evmcs_write32(unsigned long field, u32 value) {} static inline void evmcs_write16(unsigned long field, u16 value) {} static inline u64 evmcs_read64(unsigned long field) { return 0; } diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index ec9922cba30a..cf0b39f97adc 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -28,46 +28,14 @@ .macro THUNK reg - .align 32 - -SYM_FUNC_START(__x86_indirect_thunk_\reg) + .align RETPOLINE_THUNK_SIZE +SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL) + UNWIND_HINT_EMPTY ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \ __stringify(RETPOLINE \reg), X86_FEATURE_RETPOLINE, \ __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD -SYM_FUNC_END(__x86_indirect_thunk_\reg) - -.endm - -/* - * This generates .altinstr_replacement symbols for use by objtool. They, - * however, must not actually live in .altinstr_replacement since that will be - * discarded after init, but module alternatives will also reference these - * symbols. - * - * Their names matches the "__x86_indirect_" prefix to mark them as retpolines. - */ -.macro ALT_THUNK reg - - .align 1 - -SYM_FUNC_START_NOALIGN(__x86_indirect_alt_call_\reg) - ANNOTATE_RETPOLINE_SAFE -1: call *%\reg -2: .skip 5-(2b-1b), 0x90 -SYM_FUNC_END(__x86_indirect_alt_call_\reg) - -STACK_FRAME_NON_STANDARD(__x86_indirect_alt_call_\reg) - -SYM_FUNC_START_NOALIGN(__x86_indirect_alt_jmp_\reg) - ANNOTATE_RETPOLINE_SAFE -1: jmp *%\reg -2: .skip 5-(2b-1b), 0x90 -SYM_FUNC_END(__x86_indirect_alt_jmp_\reg) - -STACK_FRAME_NON_STANDARD(__x86_indirect_alt_jmp_\reg) - .endm /* @@ -85,22 +53,16 @@ STACK_FRAME_NON_STANDARD(__x86_indirect_alt_jmp_\reg) #define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym) #define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg) -#undef GEN + .align RETPOLINE_THUNK_SIZE +SYM_CODE_START(__x86_indirect_thunk_array) + #define GEN(reg) THUNK reg #include <asm/GEN-for-each-reg.h> - #undef GEN -#define GEN(reg) EXPORT_THUNK(reg) -#include <asm/GEN-for-each-reg.h> -#undef GEN -#define GEN(reg) ALT_THUNK reg -#include <asm/GEN-for-each-reg.h> + .align RETPOLINE_THUNK_SIZE +SYM_CODE_END(__x86_indirect_thunk_array) -#undef GEN -#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_call_ ## reg) +#define GEN(reg) EXPORT_THUNK(reg) #include <asm/GEN-for-each-reg.h> - #undef GEN -#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_jmp_ ## reg) -#include <asm/GEN-for-each-reg.h> diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 9ea57389c554..39c802525fce 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -15,7 +15,6 @@ #include <asm/set_memory.h> #include <asm/nospec-branch.h> #include <asm/text-patching.h> -#include <asm/asm-prototypes.h> static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) { @@ -225,6 +224,14 @@ static void jit_fill_hole(void *area, unsigned int size) struct jit_context { int cleanup_addr; /* Epilogue code offset */ + + /* + * Program specific offsets of labels in the code; these rely on the + * JIT doing at least 2 passes, recording the position on the first + * pass, only to generate the correct offset on the second pass. + */ + int tail_call_direct_label; + int tail_call_indirect_label; }; /* Maximum number of bytes emitted while JITing one eBPF insn */ @@ -380,20 +387,23 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, return __bpf_arch_text_poke(ip, t, old_addr, new_addr, true); } -static int get_pop_bytes(bool *callee_regs_used) +#define EMIT_LFENCE() EMIT3(0x0F, 0xAE, 0xE8) + +static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip) { - int bytes = 0; + u8 *prog = *pprog; - if (callee_regs_used[3]) - bytes += 2; - if (callee_regs_used[2]) - bytes += 2; - if (callee_regs_used[1]) - bytes += 2; - if (callee_regs_used[0]) - bytes += 1; +#ifdef CONFIG_RETPOLINE + if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) { + EMIT_LFENCE(); + EMIT2(0xFF, 0xE0 + reg); + } else if (cpu_feature_enabled(X86_FEATURE_RETPOLINE)) { + emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip); + } else +#endif + EMIT2(0xFF, 0xE0 + reg); - return bytes; + *pprog = prog; } /* @@ -411,29 +421,12 @@ static int get_pop_bytes(bool *callee_regs_used) * out: */ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, - u32 stack_depth) + u32 stack_depth, u8 *ip, + struct jit_context *ctx) { int tcc_off = -4 - round_up(stack_depth, 8); - u8 *prog = *pprog; - int pop_bytes = 0; - int off1 = 42; - int off2 = 31; - int off3 = 9; - - /* count the additional bytes used for popping callee regs from stack - * that need to be taken into account for each of the offsets that - * are used for bailing out of the tail call - */ - pop_bytes = get_pop_bytes(callee_regs_used); - off1 += pop_bytes; - off2 += pop_bytes; - off3 += pop_bytes; - - if (stack_depth) { - off1 += 7; - off2 += 7; - off3 += 7; - } + u8 *prog = *pprog, *start = *pprog; + int offset; /* * rdi - pointer to ctx @@ -448,8 +441,9 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, EMIT2(0x89, 0xD2); /* mov edx, edx */ EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */ offsetof(struct bpf_array, map.max_entries)); -#define OFFSET1 (off1 + RETPOLINE_RCX_BPF_JIT_SIZE) /* Number of bytes to jump */ - EMIT2(X86_JBE, OFFSET1); /* jbe out */ + + offset = ctx->tail_call_indirect_label - (prog + 2 - start); + EMIT2(X86_JBE, offset); /* jbe out */ /* * if (tail_call_cnt > MAX_TAIL_CALL_CNT) @@ -457,8 +451,9 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, */ EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ -#define OFFSET2 (off2 + RETPOLINE_RCX_BPF_JIT_SIZE) - EMIT2(X86_JA, OFFSET2); /* ja out */ + + offset = ctx->tail_call_indirect_label - (prog + 2 - start); + EMIT2(X86_JA, offset); /* ja out */ EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ @@ -471,12 +466,11 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, * goto out; */ EMIT3(0x48, 0x85, 0xC9); /* test rcx,rcx */ -#define OFFSET3 (off3 + RETPOLINE_RCX_BPF_JIT_SIZE) - EMIT2(X86_JE, OFFSET3); /* je out */ - *pprog = prog; - pop_callee_regs(pprog, callee_regs_used); - prog = *pprog; + offset = ctx->tail_call_indirect_label - (prog + 2 - start); + EMIT2(X86_JE, offset); /* je out */ + + pop_callee_regs(&prog, callee_regs_used); EMIT1(0x58); /* pop rax */ if (stack_depth) @@ -493,41 +487,21 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used, * rdi == ctx (1st arg) * rcx == prog->bpf_func + X86_TAIL_CALL_OFFSET */ - RETPOLINE_RCX_BPF_JIT(); + emit_indirect_jump(&prog, 1 /* rcx */, ip + (prog - start)); /* out: */ + ctx->tail_call_indirect_label = prog - start; *pprog = prog; } static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke, - u8 **pprog, int addr, u8 *image, - bool *callee_regs_used, u32 stack_depth) + u8 **pprog, u8 *ip, + bool *callee_regs_used, u32 stack_depth, + struct jit_context *ctx) { int tcc_off = -4 - round_up(stack_depth, 8); - u8 *prog = *pprog; - int pop_bytes = 0; - int off1 = 20; - int poke_off; - - /* count the additional bytes used for popping callee regs to stack - * that need to be taken into account for jump offset that is used for - * bailing out from of the tail call when limit is reached - */ - pop_bytes = get_pop_bytes(callee_regs_used); - off1 += pop_bytes; - - /* - * total bytes for: - * - nop5/ jmpq $off - * - pop callee regs - * - sub rsp, $val if depth > 0 - * - pop rax - */ - poke_off = X86_PATCH_SIZE + pop_bytes + 1; - if (stack_depth) { - poke_off += 7; - off1 += 7; - } + u8 *prog = *pprog, *start = *pprog; + int offset; /* * if (tail_call_cnt > MAX_TAIL_CALL_CNT) @@ -535,28 +509,30 @@ static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke, */ EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */ EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ - EMIT2(X86_JA, off1); /* ja out */ + + offset = ctx->tail_call_direct_label - (prog + 2 - start); + EMIT2(X86_JA, offset); /* ja out */ EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */ - poke->tailcall_bypass = image + (addr - poke_off - X86_PATCH_SIZE); + poke->tailcall_bypass = ip + (prog - start); poke->adj_off = X86_TAIL_CALL_OFFSET; - poke->tailcall_target = image + (addr - X86_PATCH_SIZE); + poke->tailcall_target = ip + ctx->tail_call_direct_label - X86_PATCH_SIZE; poke->bypass_addr = (u8 *)poke->tailcall_target + X86_PATCH_SIZE; emit_jump(&prog, (u8 *)poke->tailcall_target + X86_PATCH_SIZE, poke->tailcall_bypass); - *pprog = prog; - pop_callee_regs(pprog, callee_regs_used); - prog = *pprog; + pop_callee_regs(&prog, callee_regs_used); EMIT1(0x58); /* pop rax */ if (stack_depth) EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8)); memcpy(prog, x86_nops[5], X86_PATCH_SIZE); prog += X86_PATCH_SIZE; + /* out: */ + ctx->tail_call_direct_label = prog - start; *pprog = prog; } @@ -1222,8 +1198,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, /* speculation barrier */ case BPF_ST | BPF_NOSPEC: if (boot_cpu_has(X86_FEATURE_XMM2)) - /* Emit 'lfence' */ - EMIT3(0x0F, 0xAE, 0xE8); + EMIT_LFENCE(); break; /* ST: *(u8*)(dst_reg + off) = imm */ @@ -1412,13 +1387,16 @@ st: if (is_imm8(insn->off)) case BPF_JMP | BPF_TAIL_CALL: if (imm32) emit_bpf_tail_call_direct(&bpf_prog->aux->poke_tab[imm32 - 1], - &prog, addrs[i], image, + &prog, image + addrs[i - 1], callee_regs_used, - bpf_prog->aux->stack_depth); + bpf_prog->aux->stack_depth, + ctx); else emit_bpf_tail_call_indirect(&prog, callee_regs_used, - bpf_prog->aux->stack_depth); + bpf_prog->aux->stack_depth, + image + addrs[i - 1], + ctx); break; /* cond jump */ @@ -2124,24 +2102,6 @@ cleanup: return ret; } -static int emit_fallback_jump(u8 **pprog) -{ - u8 *prog = *pprog; - int err = 0; - -#ifdef CONFIG_RETPOLINE - /* Note that this assumes the the compiler uses external - * thunks for indirect calls. Both clang and GCC use the same - * naming convention for external thunks. - */ - err = emit_jump(&prog, __x86_indirect_thunk_rdx, prog); -#else - EMIT2(0xFF, 0xE2); /* jmp rdx */ -#endif - *pprog = prog; - return err; -} - static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs) { u8 *jg_reloc, *prog = *pprog; @@ -2163,9 +2123,7 @@ static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs) if (err) return err; - err = emit_fallback_jump(&prog); /* jmp thunk/indirect */ - if (err) - return err; + emit_indirect_jump(&prog, 2 /* rdx */, prog); *pprog = prog; return 0; diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c index 3bfda5f502cb..da9b7cfa4632 100644 --- a/arch/x86/net/bpf_jit_comp32.c +++ b/arch/x86/net/bpf_jit_comp32.c @@ -15,6 +15,7 @@ #include <asm/cacheflush.h> #include <asm/set_memory.h> #include <asm/nospec-branch.h> +#include <asm/asm-prototypes.h> #include <linux/bpf.h> /* @@ -1267,6 +1268,21 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth) *pprog = prog; } +static int emit_jmp_edx(u8 **pprog, u8 *ip) +{ + u8 *prog = *pprog; + int cnt = 0; + +#ifdef CONFIG_RETPOLINE + EMIT1_off32(0xE9, (u8 *)__x86_indirect_thunk_edx - (ip + 5)); +#else + EMIT2(0xFF, 0xE2); +#endif + *pprog = prog; + + return cnt; +} + /* * Generate the following code: * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... @@ -1280,7 +1296,7 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth) * goto *(prog->bpf_func + prologue_size); * out: */ -static void emit_bpf_tail_call(u8 **pprog) +static void emit_bpf_tail_call(u8 **pprog, u8 *ip) { u8 *prog = *pprog; int cnt = 0; @@ -1362,7 +1378,7 @@ static void emit_bpf_tail_call(u8 **pprog) * eax == ctx (1st arg) * edx == prog->bpf_func + prologue_size */ - RETPOLINE_EDX_BPF_JIT(); + cnt += emit_jmp_edx(&prog, ip + cnt); if (jmp_label1 == -1) jmp_label1 = cnt; @@ -2122,7 +2138,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, break; } case BPF_JMP | BPF_TAIL_CALL: - emit_bpf_tail_call(&prog); + emit_bpf_tail_call(&prog, image + addrs[i - 1]); break; /* cond jump */ diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index a7b7d674f500..4f63117f09bb 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -283,12 +283,12 @@ static void __init xen_init_capabilities(void) } } -static void xen_set_debugreg(int reg, unsigned long val) +static noinstr void xen_set_debugreg(int reg, unsigned long val) { HYPERVISOR_set_debugreg(reg, val); } -static unsigned long xen_get_debugreg(int reg) +static noinstr unsigned long xen_get_debugreg(int reg) { return HYPERVISOR_get_debugreg(reg); } @@ -1025,52 +1025,54 @@ static const struct pv_info xen_info __initconst = { .name = "Xen", }; -static const struct pv_cpu_ops xen_cpu_ops __initconst = { - .cpuid = xen_cpuid, +static const typeof(pv_ops) xen_cpu_ops __initconst = { + .cpu = { + .cpuid = xen_cpuid, - .set_debugreg = xen_set_debugreg, - .get_debugreg = xen_get_debugreg, + .set_debugreg = xen_set_debugreg, + .get_debugreg = xen_get_debugreg, - .read_cr0 = xen_read_cr0, - .write_cr0 = xen_write_cr0, + .read_cr0 = xen_read_cr0, + .write_cr0 = xen_write_cr0, - .write_cr4 = xen_write_cr4, + .write_cr4 = xen_write_cr4, - .wbinvd = native_wbinvd, + .wbinvd = native_wbinvd, - .read_msr = xen_read_msr, - .write_msr = xen_write_msr, + .read_msr = xen_read_msr, + .write_msr = xen_write_msr, - .read_msr_safe = xen_read_msr_safe, - .write_msr_safe = xen_write_msr_safe, + .read_msr_safe = xen_read_msr_safe, + .write_msr_safe = xen_write_msr_safe, - .read_pmc = xen_read_pmc, + .read_pmc = xen_read_pmc, - .load_tr_desc = paravirt_nop, - .set_ldt = xen_set_ldt, - .load_gdt = xen_load_gdt, - .load_idt = xen_load_idt, - .load_tls = xen_load_tls, - .load_gs_index = xen_load_gs_index, + .load_tr_desc = paravirt_nop, + .set_ldt = xen_set_ldt, + .load_gdt = xen_load_gdt, + .load_idt = xen_load_idt, + .load_tls = xen_load_tls, + .load_gs_index = xen_load_gs_index, - .alloc_ldt = xen_alloc_ldt, - .free_ldt = xen_free_ldt, + .alloc_ldt = xen_alloc_ldt, + .free_ldt = xen_free_ldt, - .store_tr = xen_store_tr, + .store_tr = xen_store_tr, - .write_ldt_entry = xen_write_ldt_entry, - .write_gdt_entry = xen_write_gdt_entry, - .write_idt_entry = xen_write_idt_entry, - .load_sp0 = xen_load_sp0, + .write_ldt_entry = xen_write_ldt_entry, + .write_gdt_entry = xen_write_gdt_entry, + .write_idt_entry = xen_write_idt_entry, + .load_sp0 = xen_load_sp0, #ifdef CONFIG_X86_IOPL_IOPERM - .invalidate_io_bitmap = xen_invalidate_io_bitmap, - .update_io_bitmap = xen_update_io_bitmap, + .invalidate_io_bitmap = xen_invalidate_io_bitmap, + .update_io_bitmap = xen_update_io_bitmap, #endif - .io_delay = xen_io_delay, + .io_delay = xen_io_delay, - .start_context_switch = paravirt_start_context_switch, - .end_context_switch = xen_end_context_switch, + .start_context_switch = paravirt_start_context_switch, + .end_context_switch = xen_end_context_switch, + }, }; static void xen_restart(char *msg) @@ -1211,7 +1213,7 @@ asmlinkage __visible void __init xen_start_kernel(void) /* Install Xen paravirt ops */ pv_info = xen_info; - pv_ops.cpu = xen_cpu_ops; + pv_ops.cpu = xen_cpu_ops.cpu; paravirt_iret = xen_iret; xen_init_irq_ops(); diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c index dfa091d79c2e..4fe387e520af 100644 --- a/arch/x86/xen/irq.c +++ b/arch/x86/xen/irq.c @@ -19,12 +19,12 @@ * callback mask. We do this in a very simple manner, by making a call * down into Xen. The pending flag will be checked by Xen on return. */ -void xen_force_evtchn_callback(void) +noinstr void xen_force_evtchn_callback(void) { (void)HYPERVISOR_xen_version(0, NULL); } -asmlinkage __visible unsigned long xen_save_fl(void) +asmlinkage __visible noinstr unsigned long xen_save_fl(void) { struct vcpu_info *vcpu; unsigned long flags; @@ -40,9 +40,9 @@ asmlinkage __visible unsigned long xen_save_fl(void) */ return (-flags) & X86_EFLAGS_IF; } -PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl); +__PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl, ".noinstr.text"); -asmlinkage __visible void xen_irq_disable(void) +asmlinkage __visible noinstr void xen_irq_disable(void) { /* There's a one instruction preempt window here. We need to make sure we're don't switch CPUs between getting the vcpu @@ -51,9 +51,9 @@ asmlinkage __visible void xen_irq_disable(void) this_cpu_read(xen_vcpu)->evtchn_upcall_mask = 1; preempt_enable_no_resched(); } -PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable); +__PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable, ".noinstr.text"); -asmlinkage __visible void xen_irq_enable(void) +asmlinkage __visible noinstr void xen_irq_enable(void) { struct vcpu_info *vcpu; @@ -76,7 +76,7 @@ asmlinkage __visible void xen_irq_enable(void) preempt_enable(); } -PV_CALLEE_SAVE_REGS_THUNK(xen_irq_enable); +__PV_CALLEE_SAVE_REGS_THUNK(xen_irq_enable, ".noinstr.text"); static void xen_safe_halt(void) { @@ -94,17 +94,20 @@ static void xen_halt(void) xen_safe_halt(); } -static const struct pv_irq_ops xen_irq_ops __initconst = { - .save_fl = PV_CALLEE_SAVE(xen_save_fl), - .irq_disable = PV_CALLEE_SAVE(xen_irq_disable), - .irq_enable = PV_CALLEE_SAVE(xen_irq_enable), +static const typeof(pv_ops) xen_irq_ops __initconst = { + .irq = { - .safe_halt = xen_safe_halt, - .halt = xen_halt, + .save_fl = PV_CALLEE_SAVE(xen_save_fl), + .irq_disable = PV_CALLEE_SAVE(xen_irq_disable), + .irq_enable = PV_CALLEE_SAVE(xen_irq_enable), + + .safe_halt = xen_safe_halt, + .halt = xen_halt, + }, }; void __init xen_init_irq_ops(void) { - pv_ops.irq = xen_irq_ops; + pv_ops.irq = xen_irq_ops.irq; x86_init.irqs.intr_init = xen_init_IRQ; } diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index 3359c23573c5..1ce436eeda15 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -1204,7 +1204,8 @@ static void __init xen_pagetable_init(void) xen_remap_memory(); xen_setup_mfn_list_list(); } -static void xen_write_cr2(unsigned long cr2) + +static noinstr void xen_write_cr2(unsigned long cr2) { this_cpu_read(xen_vcpu)->arch.cr2 = cr2; } @@ -2078,67 +2079,69 @@ static void xen_leave_lazy_mmu(void) preempt_enable(); } -static const struct pv_mmu_ops xen_mmu_ops __initconst = { - .read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2), - .write_cr2 = xen_write_cr2, +static const typeof(pv_ops) xen_mmu_ops __initconst = { + .mmu = { + .read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2), + .write_cr2 = xen_write_cr2, - .read_cr3 = xen_read_cr3, - .write_cr3 = xen_write_cr3_init, + .read_cr3 = xen_read_cr3, + .write_cr3 = xen_write_cr3_init, - .flush_tlb_user = xen_flush_tlb, - .flush_tlb_kernel = xen_flush_tlb, - .flush_tlb_one_user = xen_flush_tlb_one_user, - .flush_tlb_multi = xen_flush_tlb_multi, - .tlb_remove_table = tlb_remove_table, + .flush_tlb_user = xen_flush_tlb, + .flush_tlb_kernel = xen_flush_tlb, + .flush_tlb_one_user = xen_flush_tlb_one_user, + .flush_tlb_multi = xen_flush_tlb_multi, + .tlb_remove_table = tlb_remove_table, - .pgd_alloc = xen_pgd_alloc, - .pgd_free = xen_pgd_free, + .pgd_alloc = xen_pgd_alloc, + .pgd_free = xen_pgd_free, - .alloc_pte = xen_alloc_pte_init, - .release_pte = xen_release_pte_init, - .alloc_pmd = xen_alloc_pmd_init, - .release_pmd = xen_release_pmd_init, + .alloc_pte = xen_alloc_pte_init, + .release_pte = xen_release_pte_init, + .alloc_pmd = xen_alloc_pmd_init, + .release_pmd = xen_release_pmd_init, - .set_pte = xen_set_pte_init, - .set_pmd = xen_set_pmd_hyper, + .set_pte = xen_set_pte_init, + .set_pmd = xen_set_pmd_hyper, - .ptep_modify_prot_start = xen_ptep_modify_prot_start, - .ptep_modify_prot_commit = xen_ptep_modify_prot_commit, + .ptep_modify_prot_start = xen_ptep_modify_prot_start, + .ptep_modify_prot_commit = xen_ptep_modify_prot_commit, - .pte_val = PV_CALLEE_SAVE(xen_pte_val), - .pgd_val = PV_CALLEE_SAVE(xen_pgd_val), + .pte_val = PV_CALLEE_SAVE(xen_pte_val), + .pgd_val = PV_CALLEE_SAVE(xen_pgd_val), - .make_pte = PV_CALLEE_SAVE(xen_make_pte_init), - .make_pgd = PV_CALLEE_SAVE(xen_make_pgd), + .make_pte = PV_CALLEE_SAVE(xen_make_pte_init), + .make_pgd = PV_CALLEE_SAVE(xen_make_pgd), - .set_pud = xen_set_pud_hyper, + .set_pud = xen_set_pud_hyper, - .make_pmd = PV_CALLEE_SAVE(xen_make_pmd), - .pmd_val = PV_CALLEE_SAVE(xen_pmd_val), + .make_pmd = PV_CALLEE_SAVE(xen_make_pmd), + .pmd_val = PV_CALLEE_SAVE(xen_pmd_val), - .pud_val = PV_CALLEE_SAVE(xen_pud_val), - .make_pud = PV_CALLEE_SAVE(xen_make_pud), - .set_p4d = xen_set_p4d_hyper, + .pud_val = PV_CALLEE_SAVE(xen_pud_val), + .make_pud = PV_CALLEE_SAVE(xen_make_pud), + .set_p4d = xen_set_p4d_hyper, - .alloc_pud = xen_alloc_pmd_init, - .release_pud = xen_release_pmd_init, + .alloc_pud = xen_alloc_pmd_init, + .release_pud = xen_release_pmd_init, #if CONFIG_PGTABLE_LEVELS >= 5 - .p4d_val = PV_CALLEE_SAVE(xen_p4d_val), - .make_p4d = PV_CALLEE_SAVE(xen_make_p4d), + .p4d_val = PV_CALLEE_SAVE(xen_p4d_val), + .make_p4d = PV_CALLEE_SAVE(xen_make_p4d), #endif - .activate_mm = xen_activate_mm, - .dup_mmap = xen_dup_mmap, - .exit_mmap = xen_exit_mmap, + .activate_mm = xen_activate_mm, + .dup_mmap = xen_dup_mmap, + .exit_mmap = xen_exit_mmap, - .lazy_mode = { - .enter = paravirt_enter_lazy_mmu, - .leave = xen_leave_lazy_mmu, - .flush = paravirt_flush_lazy_mmu, - }, + .lazy_mode = { + .enter = paravirt_enter_lazy_mmu, + .leave = xen_leave_lazy_mmu, + .flush = paravirt_flush_lazy_mmu, + }, - .set_fixmap = xen_set_fixmap, + .set_fixmap = xen_set_fixmap, + }, }; void __init xen_init_mmu_ops(void) @@ -2146,7 +2149,7 @@ void __init xen_init_mmu_ops(void) x86_init.paging.pagetable_init = xen_pagetable_init; x86_init.hyper.init_after_bootmem = xen_after_bootmem; - pv_ops.mmu = xen_mmu_ops; + pv_ops.mmu = xen_mmu_ops.mmu; memset(dummy_mapping, 0xff, PAGE_SIZE); } diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index 1e626444712b..220dd9678494 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -21,6 +21,45 @@ #include <linux/init.h> #include <linux/linkage.h> +.pushsection .noinstr.text, "ax" +/* + * Disabling events is simply a matter of making the event mask + * non-zero. + */ +SYM_FUNC_START(xen_irq_disable_direct) + movb $1, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask + ret +SYM_FUNC_END(xen_irq_disable_direct) + +/* + * Force an event check by making a hypercall, but preserve regs + * before making the call. + */ +SYM_FUNC_START(check_events) + FRAME_BEGIN + push %rax + push %rcx + push %rdx + push %rsi + push %rdi + push %r8 + push %r9 + push %r10 + push %r11 + call xen_force_evtchn_callback + pop %r11 + pop %r10 + pop %r9 + pop %r8 + pop %rdi + pop %rsi + pop %rdx + pop %rcx + pop %rax + FRAME_END + ret +SYM_FUNC_END(check_events) + /* * Enable events. This clears the event mask and tests the pending * event status with one and operation. If there are pending events, @@ -47,16 +86,6 @@ SYM_FUNC_START(xen_irq_enable_direct) ret SYM_FUNC_END(xen_irq_enable_direct) - -/* - * Disabling events is simply a matter of making the event mask - * non-zero. - */ -SYM_FUNC_START(xen_irq_disable_direct) - movb $1, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask - ret -SYM_FUNC_END(xen_irq_disable_direct) - /* * (xen_)save_fl is used to get the current interrupt enable status. * Callers expect the status to be in X86_EFLAGS_IF, and other bits @@ -73,35 +102,6 @@ SYM_FUNC_START(xen_save_fl_direct) ret SYM_FUNC_END(xen_save_fl_direct) -/* - * Force an event check by making a hypercall, but preserve regs - * before making the call. - */ -SYM_FUNC_START(check_events) - FRAME_BEGIN - push %rax - push %rcx - push %rdx - push %rsi - push %rdi - push %r8 - push %r9 - push %r10 - push %r11 - call xen_force_evtchn_callback - pop %r11 - pop %r10 - pop %r9 - pop %r8 - pop %rdi - pop %rsi - pop %rdx - pop %rcx - pop %rax - FRAME_END - ret -SYM_FUNC_END(check_events) - SYM_FUNC_START(xen_read_cr2) FRAME_BEGIN _ASM_MOV PER_CPU_VAR(xen_vcpu), %_ASM_AX @@ -116,6 +116,7 @@ SYM_FUNC_START(xen_read_cr2_direct) FRAME_END ret SYM_FUNC_END(xen_read_cr2_direct); +.popsection .macro xen_pv_trap name SYM_CODE_START(xen_\name) diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index cb6538ae2fe0..9e27b86a0c31 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -20,6 +20,23 @@ #include <xen/interface/xen-mca.h> #include <asm/xen/interface.h> +.pushsection .noinstr.text, "ax" + .balign PAGE_SIZE +SYM_CODE_START(hypercall_page) + .rept (PAGE_SIZE / 32) + UNWIND_HINT_FUNC + .skip 31, 0x90 + ret + .endr + +#define HYPERCALL(n) \ + .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \ + .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32 +#include <asm/xen-hypercalls.h> +#undef HYPERCALL +SYM_CODE_END(hypercall_page) +.popsection + #ifdef CONFIG_XEN_PV __INIT SYM_CODE_START(startup_xen) @@ -64,23 +81,6 @@ SYM_CODE_END(asm_cpu_bringup_and_idle) #endif #endif -.pushsection .text - .balign PAGE_SIZE -SYM_CODE_START(hypercall_page) - .rept (PAGE_SIZE / 32) - UNWIND_HINT_FUNC - .skip 31, 0x90 - ret - .endr - -#define HYPERCALL(n) \ - .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \ - .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32 -#include <asm/xen-hypercalls.h> -#undef HYPERCALL -SYM_CODE_END(hypercall_page) -.popsection - ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS, .asciz "linux") ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION, .asciz "2.6") ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION, .asciz "xen-3.0") |