From 8533bbe9f87b01f49ff951f665ea1988252fa3c2 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 30 Jan 2008 13:31:21 +0100 Subject: [PATCH] x86: prepare kprobes code for x86 unification This patch cleanup kprobes code on x86 for unification. This patch is based on Arjan's previous work. - Remove spurious whitespace changes - Add harmless includes - Make the 32/64 files more identical - Generalize structure fields' and local variable name. - Wrap accessing to stack address by macros. - Modify bitmap making macro. - Merge fixup code into is_riprel() and change its name to fix_riprel(). - Set MAX_INSN_SIZE to 16 on both arch. - Use u32 for bitmaps on both architectures. - Clarify some comments. Signed-off-by: Masami Hiramatsu Signed-off-by: Arjan van de Ven Signed-off-by: Jim Keniston Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/kprobes_32.c | 321 ++++++++++++++++++++------------- arch/x86/kernel/kprobes_64.c | 409 ++++++++++++++++++++++--------------------- arch/x86/mm/fault_32.c | 1 - arch/x86/mm/fault_64.c | 1 - include/asm-x86/kprobes_32.h | 32 ++-- include/asm-x86/kprobes_64.h | 30 ++-- 6 files changed, 447 insertions(+), 347 deletions(-) diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c index 8eccd2d..8e06431 100644 --- a/arch/x86/kernel/kprobes_32.c +++ b/arch/x86/kernel/kprobes_32.c @@ -29,10 +29,15 @@ #include #include +#include +#include #include +#include #include + #include #include +#include #include #include @@ -41,65 +46,121 @@ void jprobe_return_end(void); DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); +/* + * "®s->sp" looks wrong, but it's correct for x86_32. x86_32 CPUs + * don't save the ss and esp registers if the CPU is already in kernel + * mode when it traps. So for kprobes, regs->sp and regs->ss are not + * the [nonexistent] saved stack pointer and ss register, but rather + * the top 8 bytes of the pre-int3 stack. So ®s->sp happens to + * point to the top of the pre-int3 stack. + */ +#define stack_addr(regs) ((unsigned long *)®s->sp) + +#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\ + (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ + (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \ + (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \ + (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \ + << (row % 32)) + /* + * Undefined/reserved opcodes, conditional jump, Opcode Extension + * Groups, and some special opcodes can not boost. + */ +static const u32 twobyte_is_boostable[256 / 32] = { + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ + /* ---------------------------------------------- */ + W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) | /* 00 */ + W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 10 */ + W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 20 */ + W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */ + W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */ + W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */ + W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) | /* 60 */ + W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */ + W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 80 */ + W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */ + W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* a0 */ + W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) , /* b0 */ + W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */ + W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) , /* d0 */ + W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* e0 */ + W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */ + /* ----------------------------------------------- */ + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ +}; +static const u32 onebyte_has_modrm[256 / 32] = { + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ + /* ----------------------------------------------- */ + W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 00 */ + W(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 10 */ + W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 20 */ + W(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 30 */ + W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */ + W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */ + W(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) | /* 60 */ + W(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 70 */ + W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */ + W(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 90 */ + W(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* a0 */ + W(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* b0 */ + W(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* c0 */ + W(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */ + W(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* e0 */ + W(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */ + /* ----------------------------------------------- */ + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ +}; +static const u32 twobyte_has_modrm[256 / 32] = { + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ + /* ----------------------------------------------- */ + W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) | /* 0f */ + W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) , /* 1f */ + W(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 2f */ + W(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 3f */ + W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 4f */ + W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 5f */ + W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 6f */ + W(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) , /* 7f */ + W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 8f */ + W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 9f */ + W(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) | /* af */ + W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) , /* bf */ + W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* cf */ + W(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* df */ + W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* ef */ + W(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */ + /* ----------------------------------------------- */ + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ +}; +#undef W + struct kretprobe_blackpoint kretprobe_blacklist[] = { {"__switch_to", }, /* This function switches only current task, but - doesn't switch kernel stack.*/ + doesn't switch kernel stack.*/ {NULL, NULL} /* Terminator */ }; const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist); -/* insert a jmp code */ +/* Insert a jump instruction at address 'from', which jumps to address 'to'.*/ static __always_inline void set_jmp_op(void *from, void *to) { struct __arch_jmp_op { char op; - long raddr; - } __attribute__((packed)) *jop; + s32 raddr; + } __attribute__((packed)) * jop; jop = (struct __arch_jmp_op *)from; - jop->raddr = (long)(to) - ((long)(from) + 5); + jop->raddr = (s32)((long)(to) - ((long)(from) + 5)); jop->op = RELATIVEJUMP_INSTRUCTION; } /* - * returns non-zero if opcodes can be boosted. + * returns non-zero if opcode is boostable. */ static __always_inline int can_boost(kprobe_opcode_t *opcodes) { -#define W(row,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,ba,bb,bc,bd,be,bf) \ - (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ - (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \ - (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \ - (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \ - << (row % 32)) - /* - * Undefined/reserved opcodes, conditional jump, Opcode Extension - * Groups, and some special opcodes can not be boost. - */ - static const unsigned long twobyte_is_boostable[256 / 32] = { - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - /* ------------------------------- */ - W(0x00, 0,0,1,1,0,0,1,0,1,1,0,0,0,0,0,0)| /* 00 */ - W(0x10, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 10 */ - W(0x20, 1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0)| /* 20 */ - W(0x30, 0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 30 */ - W(0x40, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 40 */ - W(0x50, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 50 */ - W(0x60, 1,1,1,1,1,1,1,1,1,1,1,1,0,0,1,1)| /* 60 */ - W(0x70, 0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1), /* 70 */ - W(0x80, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 80 */ - W(0x90, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1), /* 90 */ - W(0xa0, 1,1,0,1,1,1,0,0,1,1,0,1,1,1,0,1)| /* a0 */ - W(0xb0, 1,1,1,1,1,1,1,1,0,0,0,1,1,1,1,1), /* b0 */ - W(0xc0, 1,1,0,0,0,0,0,0,1,1,1,1,1,1,1,1)| /* c0 */ - W(0xd0, 0,1,1,1,0,1,0,0,1,1,0,1,1,1,0,1), /* d0 */ - W(0xe0, 0,1,1,0,0,1,0,0,1,1,0,1,1,1,0,1)| /* e0 */ - W(0xf0, 0,1,1,1,0,1,0,0,1,1,1,0,1,1,1,0) /* f0 */ - /* ------------------------------- */ - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - }; -#undef W kprobe_opcode_t opcode; kprobe_opcode_t *orig_opcodes = opcodes; + retry: if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) return 0; @@ -109,7 +170,8 @@ retry: if (opcode == 0x0f) { if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) return 0; - return test_bit(*opcodes, twobyte_is_boostable); + return test_bit(*opcodes, + (unsigned long *)twobyte_is_boostable); } switch (opcode & 0xf0) { @@ -132,12 +194,13 @@ retry: case 0xf0: if ((opcode & 0x0c) == 0 && opcode != 0xf1) goto retry; /* lock/rep(ne) prefix */ - /* clear and set flags can be boost */ + /* clear and set flags are boostable */ return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe)); default: + /* segment override prefixes are boostable */ if (opcode == 0x26 || opcode == 0x36 || opcode == 0x3e) goto retry; /* prefixes */ - /* can't boost CS override and call */ + /* CS override prefix and call are not boostable */ return (opcode != 0x2e && opcode != 0x9a); } } @@ -145,9 +208,9 @@ retry: /* * returns non-zero if opcode modifies the interrupt flag. */ -static int __kprobes is_IF_modifier(kprobe_opcode_t opcode) +static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) { - switch (opcode) { + switch (*insn) { case 0xfa: /* cli */ case 0xfb: /* sti */ case 0xcf: /* iret/iretd */ @@ -157,20 +220,24 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t opcode) return 0; } +static void __kprobes arch_copy_kprobe(struct kprobe *p) +{ + memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); + if (can_boost(p->addr)) + p->ainsn.boostable = 0; + else + p->ainsn.boostable = -1; + + p->opcode = *p->addr; +} + int __kprobes arch_prepare_kprobe(struct kprobe *p) { - /* insn: must be on special executable page on i386. */ + /* insn: must be on special executable page on x86. */ p->ainsn.insn = get_insn_slot(); if (!p->ainsn.insn) return -ENOMEM; - - memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); - p->opcode = *p->addr; - if (can_boost(p->addr)) { - p->ainsn.boostable = 0; - } else { - p->ainsn.boostable = -1; - } + arch_copy_kprobe(p); return 0; } @@ -195,26 +262,26 @@ static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) { kcb->prev_kprobe.kp = kprobe_running(); kcb->prev_kprobe.status = kcb->kprobe_status; - kcb->prev_kprobe.old_eflags = kcb->kprobe_old_eflags; - kcb->prev_kprobe.saved_eflags = kcb->kprobe_saved_eflags; + kcb->prev_kprobe.old_flags = kcb->kprobe_old_flags; + kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags; } static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; kcb->kprobe_status = kcb->prev_kprobe.status; - kcb->kprobe_old_eflags = kcb->prev_kprobe.old_eflags; - kcb->kprobe_saved_eflags = kcb->prev_kprobe.saved_eflags; + kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags; + kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags; } static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = p; - kcb->kprobe_saved_eflags = kcb->kprobe_old_eflags + kcb->kprobe_saved_flags = kcb->kprobe_old_flags = (regs->flags & (TF_MASK | IF_MASK)); - if (is_IF_modifier(p->opcode)) - kcb->kprobe_saved_eflags &= ~IF_MASK; + if (is_IF_modifier(p->ainsn.insn)) + kcb->kprobe_saved_flags &= ~IF_MASK; } static __always_inline void clear_btf(void) @@ -245,7 +312,7 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { - unsigned long *sara = (unsigned long *)®s->sp; + unsigned long *sara = stack_addr(regs); ri->ret_addr = (kprobe_opcode_t *) *sara; @@ -280,7 +347,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) if (kcb->kprobe_status == KPROBE_HIT_SS && *p->ainsn.insn == BREAKPOINT_INSTRUCTION) { regs->flags &= ~TF_MASK; - regs->flags |= kcb->kprobe_saved_eflags; + regs->flags |= kcb->kprobe_saved_flags; goto no_kprobe; } /* We have reentered the kprobe_handler(), since @@ -301,7 +368,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) * another cpu right after we hit, no further * handling of this interrupt is appropriate */ - regs->ip -= sizeof(kprobe_opcode_t); + regs->ip = (unsigned long)addr; ret = 1; goto no_kprobe; } @@ -325,7 +392,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) * Back up over the (now missing) int3 and run * the original instruction. */ - regs->ip -= sizeof(kprobe_opcode_t); + regs->ip = (unsigned long)addr; ret = 1; } /* Not one of ours: let kernel handle it */ @@ -341,7 +408,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) ss_probe: #if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM) - if (p->ainsn.boostable == 1 && !p->post_handler){ + if (p->ainsn.boostable == 1 && !p->post_handler) { /* Boost up -- we can execute copied instructions directly */ reset_current_kprobe(); regs->ip = (unsigned long)p->ainsn.insn; @@ -359,16 +426,18 @@ no_kprobe: } /* - * For function-return probes, init_kprobes() establishes a probepoint - * here. When a retprobed function returns, this probe is hit and - * trampoline_probe_handler() runs, calling the kretprobe's handler. + * When a retprobed function returns, this code saves registers and + * calls trampoline_handler() runs, which calls the kretprobe's handler. */ void __kprobes kretprobe_trampoline_holder(void) { asm volatile ( ".global kretprobe_trampoline\n" "kretprobe_trampoline: \n" " pushf\n" - /* skip cs, ip, orig_ax */ + /* + * Skip cs, ip, orig_ax. + * trampoline_handler() will plug in these values + */ " subl $12, %esp\n" " pushl %fs\n" " pushl %ds\n" @@ -382,10 +451,10 @@ no_kprobe: " pushl %ebx\n" " movl %esp, %eax\n" " call trampoline_handler\n" - /* move flags to cs */ + /* Move flags to cs */ " movl 52(%esp), %edx\n" " movl %edx, 48(%esp)\n" - /* save true return address on flags */ + /* Replace saved flags with true return address. */ " movl %eax, 52(%esp)\n" " popl %ebx\n" " popl %ecx\n" @@ -394,16 +463,16 @@ no_kprobe: " popl %edi\n" " popl %ebp\n" " popl %eax\n" - /* skip ip, orig_ax, es, ds, fs */ + /* Skip ip, orig_ax, es, ds, fs */ " addl $20, %esp\n" " popf\n" " ret\n"); -} + } /* * Called from kretprobe_trampoline */ -void *__kprobes trampoline_handler(struct pt_regs *regs) +void * __kprobes trampoline_handler(struct pt_regs *regs) { struct kretprobe_instance *ri = NULL; struct hlist_head *head, empty_rp; @@ -417,27 +486,27 @@ void *__kprobes trampoline_handler(struct pt_regs *regs) /* fixup registers */ regs->cs = __KERNEL_CS | get_kernel_rpl(); regs->ip = trampoline_address; - regs->orig_ax = 0xffffffff; + regs->orig_ax = ~0UL; /* * It is possible to have multiple instances associated with a given - * task either because an multiple functions in the call path - * have a return probe installed on them, and/or more then one return + * task either because multiple functions in the call path have + * return probes installed on them, and/or more then one * return probe was registered for a target function. * * We can handle this because: - * - instances are always inserted at the head of the list + * - instances are always pushed into the head of the list * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to the - * real return address, and all the rest will point to - * kretprobe_trampoline + * function, the (chronologically) first instance's ret_addr + * will be the real return address, and all the rest will + * point to kretprobe_trampoline. */ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { if (ri->task != current) /* another task is sharing our hash bucket */ continue; - if (ri->rp && ri->rp->handler){ + if (ri->rp && ri->rp->handler) { __get_cpu_var(current_kprobe) = &ri->rp->kp; get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; ri->rp->handler(ri, regs); @@ -457,13 +526,14 @@ void *__kprobes trampoline_handler(struct pt_regs *regs) } kretprobe_assert(ri, orig_ret_address, trampoline_address); + spin_unlock_irqrestore(&kretprobe_lock, flags); hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); } - return (void*)orig_ret_address; + return (void *)orig_ret_address; } /* @@ -488,48 +558,55 @@ void *__kprobes trampoline_handler(struct pt_regs *regs) * that is atop the stack is the address following the copied instruction. * We need to make it the address following the original instruction. * - * This function also checks instruction size for preparing direct execution. + * If this is the first time we've single-stepped the instruction at + * this probepoint, and the instruction is boostable, boost it: add a + * jump instruction after the copied instruction, that jumps to the next + * instruction after the probepoint. */ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { - unsigned long *tos = (unsigned long *)®s->sp; - unsigned long copy_eip = (unsigned long)p->ainsn.insn; - unsigned long orig_eip = (unsigned long)p->addr; + unsigned long *tos = stack_addr(regs); + unsigned long copy_ip = (unsigned long)p->ainsn.insn; + unsigned long orig_ip = (unsigned long)p->addr; + kprobe_opcode_t *insn = p->ainsn.insn; regs->flags &= ~TF_MASK; - switch (p->ainsn.insn[0]) { - case 0x9c: /* pushfl */ + switch (*insn) { + case 0x9c: /* pushfl */ *tos &= ~(TF_MASK | IF_MASK); - *tos |= kcb->kprobe_old_eflags; + *tos |= kcb->kprobe_old_flags; break; - case 0xc2: /* iret/ret/lret */ + case 0xc2: /* iret/ret/lret */ case 0xc3: case 0xca: case 0xcb: case 0xcf: - case 0xea: /* jmp absolute -- ip is correct */ + case 0xea: /* jmp absolute -- ip is correct */ /* ip is already adjusted, no more changes required */ p->ainsn.boostable = 1; goto no_change; - case 0xe8: /* call relative - Fix return addr */ - *tos = orig_eip + (*tos - copy_eip); + case 0xe8: /* call relative - Fix return addr */ + *tos = orig_ip + (*tos - copy_ip); break; - case 0x9a: /* call absolute -- same as call absolute, indirect */ - *tos = orig_eip + (*tos - copy_eip); + case 0x9a: /* call absolute -- same as call absolute, indirect */ + *tos = orig_ip + (*tos - copy_ip); goto no_change; case 0xff: - if ((p->ainsn.insn[1] & 0x30) == 0x10) { + if ((insn[1] & 0x30) == 0x10) { /* * call absolute, indirect * Fix return addr; ip is correct. * But this is not boostable */ - *tos = orig_eip + (*tos - copy_eip); + *tos = orig_ip + (*tos - copy_ip); goto no_change; - } else if (((p->ainsn.insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */ - ((p->ainsn.insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */ - /* ip is correct. And this is boostable */ + } else if (((insn[1] & 0x31) == 0x20) || + ((insn[1] & 0x31) == 0x21)) { + /* + * jmp near and far, absolute indirect + * ip is correct. And this is boostable + */ p->ainsn.boostable = 1; goto no_change; } @@ -538,21 +615,21 @@ static void __kprobes resume_execution(struct kprobe *p, } if (p->ainsn.boostable == 0) { - if ((regs->ip > copy_eip) && - (regs->ip - copy_eip) + 5 < MAX_INSN_SIZE) { + if ((regs->ip > copy_ip) && + (regs->ip - copy_ip) + 5 < MAX_INSN_SIZE) { /* * These instructions can be executed directly if it * jumps back to correct address. */ set_jmp_op((void *)regs->ip, - (void *)orig_eip + (regs->ip - copy_eip)); + (void *)orig_ip + (regs->ip - copy_ip)); p->ainsn.boostable = 1; } else { p->ainsn.boostable = -1; } } - regs->ip = orig_eip + (regs->ip - copy_eip); + regs->ip += orig_ip - copy_ip; no_change: restore_btf(); @@ -578,10 +655,10 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) } resume_execution(cur, regs, kcb); - regs->flags |= kcb->kprobe_saved_eflags; + regs->flags |= kcb->kprobe_saved_flags; trace_hardirqs_fixup_flags(regs->flags); - /*Restore back the original saved kprobes variables and continue. */ + /* Restore back the original saved kprobes variables and continue. */ if (kcb->kprobe_status == KPROBE_REENTER) { restore_previous_kprobe(kcb); goto out; @@ -617,7 +694,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) * normal page fault. */ regs->ip = (unsigned long)cur->addr; - regs->flags |= kcb->kprobe_old_eflags; + regs->flags |= kcb->kprobe_old_flags; if (kcb->kprobe_status == KPROBE_REENTER) restore_previous_kprobe(kcb); else @@ -628,7 +705,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) case KPROBE_HIT_SSDONE: /* * We increment the nmissed count for accounting, - * we can also use npre/npostfault count for accouting + * we can also use npre/npostfault count for accounting * these specific fault cases. */ kprobes_inc_nmissed_count(cur); @@ -651,7 +728,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) return 1; /* - * fixup_exception() could not handle it, + * fixup routine could not handle it, * Let do_page_fault() fix it. */ break; @@ -662,7 +739,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) } /* - * Wrapper routine to for handling exceptions. + * Wrapper routine for handling exceptions. */ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) @@ -703,11 +780,11 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); kcb->jprobe_saved_regs = *regs; - kcb->jprobe_saved_esp = ®s->sp; - addr = (unsigned long)(kcb->jprobe_saved_esp); + kcb->jprobe_saved_sp = stack_addr(regs); + addr = (unsigned long)(kcb->jprobe_saved_sp); /* - * TBD: As Linus pointed out, gcc assumes that the callee + * As Linus pointed out, gcc assumes that the callee * owns the argument space and could overwrite it, e.g. * tailcall optimization. So, to be absolutely safe * we also save and restore enough stack bytes to cover @@ -730,21 +807,20 @@ void __kprobes jprobe_return(void) " .globl jprobe_return_end \n" " jprobe_return_end: \n" " nop \n"::"b" - (kcb->jprobe_saved_esp):"memory"); + (kcb->jprobe_saved_sp):"memory"); } int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); u8 *addr = (u8 *) (regs->ip - 1); - unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_esp); struct jprobe *jp = container_of(p, struct jprobe, kp); if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) { - if (®s->sp != kcb->jprobe_saved_esp) { + if (stack_addr(regs) != kcb->jprobe_saved_sp) { struct pt_regs *saved_regs = &kcb->jprobe_saved_regs; printk("current sp %p does not match saved sp %p\n", - ®s->sp, kcb->jprobe_saved_esp); + stack_addr(regs), kcb->jprobe_saved_sp); printk("Saved registers for jprobe %p\n", jp); show_registers(saved_regs); printk("Current registers\n"); @@ -752,20 +828,21 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) BUG(); } *regs = kcb->jprobe_saved_regs; - memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack, - MIN_STACK_SIZE(stack_addr)); + memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp), + kcb->jprobes_stack, + MIN_STACK_SIZE(kcb->jprobe_saved_sp)); preempt_enable_no_resched(); return 1; } return 0; } -int __kprobes arch_trampoline_kprobe(struct kprobe *p) +int __init arch_init_kprobes(void) { return 0; } -int __init arch_init_kprobes(void) +int __kprobes arch_trampoline_kprobe(struct kprobe *p) { return 0; } diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c index bc93b1d..2d77637 100644 --- a/arch/x86/kernel/kprobes_64.c +++ b/arch/x86/kernel/kprobes_64.c @@ -40,16 +40,97 @@ #include #include +#include +#include #include #include #include void jprobe_return_end(void); -static void __kprobes arch_copy_kprobe(struct kprobe *p); DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); +#define stack_addr(regs) ((unsigned long *)regs->sp) + +#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\ + (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ + (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \ + (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \ + (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \ + << (row % 32)) + /* + * Undefined/reserved opcodes, conditional jump, Opcode Extension + * Groups, and some special opcodes can not boost. + */ +static const u32 twobyte_is_boostable[256 / 32] = { + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ + /* ---------------------------------------------- */ + W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) | /* 00 */ + W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 10 */ + W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 20 */ + W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */ + W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */ + W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */ + W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) | /* 60 */ + W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */ + W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 80 */ + W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */ + W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* a0 */ + W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) , /* b0 */ + W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */ + W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) , /* d0 */ + W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* e0 */ + W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */ + /* ----------------------------------------------- */ + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ +}; +static const u32 onebyte_has_modrm[256 / 32] = { + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ + /* ----------------------------------------------- */ + W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 00 */ + W(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 10 */ + W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 20 */ + W(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 30 */ + W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */ + W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */ + W(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) | /* 60 */ + W(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 70 */ + W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */ + W(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 90 */ + W(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* a0 */ + W(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* b0 */ + W(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* c0 */ + W(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */ + W(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* e0 */ + W(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */ + /* ----------------------------------------------- */ + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ +}; +static const u32 twobyte_has_modrm[256 / 32] = { + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ + /* ----------------------------------------------- */ + W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) | /* 0f */ + W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) , /* 1f */ + W(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 2f */ + W(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 3f */ + W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 4f */ + W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 5f */ + W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 6f */ + W(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) , /* 7f */ + W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 8f */ + W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 9f */ + W(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) | /* af */ + W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) , /* bf */ + W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* cf */ + W(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* df */ + W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* ef */ + W(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */ + /* ----------------------------------------------- */ + /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ +}; +#undef W + struct kretprobe_blackpoint kretprobe_blacklist[] = { {"__switch_to", }, /* This function switches only current task, but doesn't switch kernel stack.*/ @@ -70,44 +151,11 @@ static __always_inline void set_jmp_op(void *from, void *to) } /* - * returns non-zero if opcode is boostable + * returns non-zero if opcode is boostable. * RIP relative instructions are adjusted at copying time */ static __always_inline int can_boost(kprobe_opcode_t *opcodes) { -#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\ - (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ - (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \ - (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \ - (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \ - << (row % 64)) - /* - * Undefined/reserved opcodes, conditional jump, Opcode Extension - * Groups, and some special opcodes can not boost. - */ - static const unsigned long twobyte_is_boostable[256 / 64] = { - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - /* ---------------------------------------------- */ - W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0)|/* 00 */ - W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 10 */ - W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 20 */ - W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0),/* 30 */ - W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)|/* 40 */ - W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 50 */ - W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1)|/* 60 */ - W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1),/* 70 */ - W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 80 */ - W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)|/* 90 */ - W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1)|/* a0 */ - W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1),/* b0 */ - W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1)|/* c0 */ - W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1)|/* d0 */ - W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1)|/* e0 */ - W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */ - /* ----------------------------------------------- */ - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - }; -#undef W kprobe_opcode_t opcode; kprobe_opcode_t *orig_opcodes = opcodes; @@ -120,7 +168,8 @@ retry: if (opcode == 0x0f) { if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) return 0; - return test_bit(*opcodes, twobyte_is_boostable); + return test_bit(*opcodes, + (unsigned long *)twobyte_is_boostable); } switch (opcode & 0xf0) { @@ -169,80 +218,25 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) return 1; } - if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf) - return 1; - return 0; -} - -int __kprobes arch_prepare_kprobe(struct kprobe *p) -{ - /* insn: must be on special executable page on x86_64. */ - p->ainsn.insn = get_insn_slot(); - if (!p->ainsn.insn) { - return -ENOMEM; - } - arch_copy_kprobe(p); + /* + * on 64 bit x86, 0x40-0x4f are prefixes so we need to look + * at the next byte instead.. but of course not recurse infinitely + */ + if (*insn >= 0x40 && *insn <= 0x4f) + return is_IF_modifier(++insn); return 0; } /* - * Determine if the instruction uses the %rip-relative addressing mode. + * Adjust the displacement if the instruction uses the %rip-relative + * addressing mode. * If it does, Return the address of the 32-bit displacement word. * If not, return null. */ -static s32 __kprobes *is_riprel(u8 *insn) +static void __kprobes fix_riprel(struct kprobe *p) { -#define W(row,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,ba,bb,bc,bd,be,bf) \ - (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \ - (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \ - (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \ - (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \ - << (row % 64)) - static const u64 onebyte_has_modrm[256 / 64] = { - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - /* ------------------------------- */ - W(0x00, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0)| /* 00 */ - W(0x10, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0)| /* 10 */ - W(0x20, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0)| /* 20 */ - W(0x30, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0), /* 30 */ - W(0x40, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 40 */ - W(0x50, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 50 */ - W(0x60, 0,0,1,1,0,0,0,0,0,1,0,1,0,0,0,0)| /* 60 */ - W(0x70, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 70 */ - W(0x80, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 80 */ - W(0x90, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 90 */ - W(0xa0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* a0 */ - W(0xb0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* b0 */ - W(0xc0, 1,1,0,0,1,1,1,1,0,0,0,0,0,0,0,0)| /* c0 */ - W(0xd0, 1,1,1,1,0,0,0,0,1,1,1,1,1,1,1,1)| /* d0 */ - W(0xe0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* e0 */ - W(0xf0, 0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1) /* f0 */ - /* ------------------------------- */ - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - }; - static const u64 twobyte_has_modrm[256 / 64] = { - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - /* ------------------------------- */ - W(0x00, 1,1,1,1,0,0,0,0,0,0,0,0,0,1,0,1)| /* 0f */ - W(0x10, 1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0)| /* 1f */ - W(0x20, 1,1,1,1,1,0,1,0,1,1,1,1,1,1,1,1)| /* 2f */ - W(0x30, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 3f */ - W(0x40, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 4f */ - W(0x50, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 5f */ - W(0x60, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 6f */ - W(0x70, 1,1,1,1,1,1,1,0,0,0,0,0,1,1,1,1), /* 7f */ - W(0x80, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 8f */ - W(0x90, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 9f */ - W(0xa0, 0,0,0,1,1,1,1,1,0,0,0,1,1,1,1,1)| /* af */ - W(0xb0, 1,1,1,1,1,1,1,1,0,0,1,1,1,1,1,1), /* bf */ - W(0xc0, 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0)| /* cf */ - W(0xd0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* df */ - W(0xe0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* ef */ - W(0xf0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0) /* ff */ - /* ------------------------------- */ - /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */ - }; -#undef W + u8 *insn = p->ainsn.insn; + s64 disp; int need_modrm; /* Skip legacy instruction prefixes. */ @@ -271,54 +265,60 @@ static s32 __kprobes *is_riprel(u8 *insn) if (*insn == 0x0f) { /* Two-byte opcode. */ ++insn; - need_modrm = test_bit(*insn, twobyte_has_modrm); - } else { /* One-byte opcode. */ - need_modrm = test_bit(*insn, onebyte_has_modrm); - } + need_modrm = test_bit(*insn, + (unsigned long *)twobyte_has_modrm); + } else /* One-byte opcode. */ + need_modrm = test_bit(*insn, + (unsigned long *)onebyte_has_modrm); if (need_modrm) { u8 modrm = *++insn; if ((modrm & 0xc7) == 0x05) { /* %rip+disp32 addressing mode */ /* Displacement follows ModRM byte. */ - return (s32 *) ++insn; + ++insn; + /* + * The copied instruction uses the %rip-relative + * addressing mode. Adjust the displacement for the + * difference between the original location of this + * instruction and the location of the copy that will + * actually be run. The tricky bit here is making sure + * that the sign extension happens correctly in this + * calculation, since we need a signed 32-bit result to + * be sign-extended to 64 bits when it's added to the + * %rip value and yield the same 64-bit result that the + * sign-extension of the original signed 32-bit + * displacement would have given. + */ + disp = (u8 *) p->addr + *((s32 *) insn) - + (u8 *) p->ainsn.insn; + BUG_ON((s64) (s32) disp != disp); /* Sanity check. */ + *(s32 *)insn = (s32) disp; } } - - /* No %rip-relative addressing mode here. */ - return NULL; } static void __kprobes arch_copy_kprobe(struct kprobe *p) { - s32 *ripdisp; - memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE); - ripdisp = is_riprel(p->ainsn.insn); - if (ripdisp) { - /* - * The copied instruction uses the %rip-relative - * addressing mode. Adjust the displacement for the - * difference between the original location of this - * instruction and the location of the copy that will - * actually be run. The tricky bit here is making sure - * that the sign extension happens correctly in this - * calculation, since we need a signed 32-bit result to - * be sign-extended to 64 bits when it's added to the - * %rip value and yield the same 64-bit result that the - * sign-extension of the original signed 32-bit - * displacement would have given. - */ - s64 disp = (u8 *) p->addr + *ripdisp - (u8 *) p->ainsn.insn; - BUG_ON((s64) (s32) disp != disp); /* Sanity check. */ - *ripdisp = disp; - } - if (can_boost(p->addr)) { + memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); + fix_riprel(p); + if (can_boost(p->addr)) p->ainsn.boostable = 0; - } else { + else p->ainsn.boostable = -1; - } + p->opcode = *p->addr; } +int __kprobes arch_prepare_kprobe(struct kprobe *p) +{ + /* insn: must be on special executable page on x86. */ + p->ainsn.insn = get_insn_slot(); + if (!p->ainsn.insn) + return -ENOMEM; + arch_copy_kprobe(p); + return 0; +} + void __kprobes arch_arm_kprobe(struct kprobe *p) { text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1); @@ -340,26 +340,26 @@ static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) { kcb->prev_kprobe.kp = kprobe_running(); kcb->prev_kprobe.status = kcb->kprobe_status; - kcb->prev_kprobe.old_rflags = kcb->kprobe_old_rflags; - kcb->prev_kprobe.saved_rflags = kcb->kprobe_saved_rflags; + kcb->prev_kprobe.old_flags = kcb->kprobe_old_flags; + kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags; } static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; kcb->kprobe_status = kcb->prev_kprobe.status; - kcb->kprobe_old_rflags = kcb->prev_kprobe.old_rflags; - kcb->kprobe_saved_rflags = kcb->prev_kprobe.saved_rflags; + kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags; + kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags; } static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = p; - kcb->kprobe_saved_rflags = kcb->kprobe_old_rflags + kcb->kprobe_saved_flags = kcb->kprobe_old_flags = (regs->flags & (TF_MASK | IF_MASK)); if (is_IF_modifier(p->ainsn.insn)) - kcb->kprobe_saved_rflags &= ~IF_MASK; + kcb->kprobe_saved_flags &= ~IF_MASK; } static __always_inline void clear_btf(void) @@ -390,20 +390,27 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { - unsigned long *sara = (unsigned long *)regs->sp; + unsigned long *sara = stack_addr(regs); ri->ret_addr = (kprobe_opcode_t *) *sara; + /* Replace the return addr with trampoline addr */ *sara = (unsigned long) &kretprobe_trampoline; } -int __kprobes kprobe_handler(struct pt_regs *regs) +/* + * Interrupts are disabled on entry as trap3 is an interrupt gate and they + * remain disabled thorough out this function. + */ +static int __kprobes kprobe_handler(struct pt_regs *regs) { struct kprobe *p; int ret = 0; - kprobe_opcode_t *addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t)); + kprobe_opcode_t *addr; struct kprobe_ctlblk *kcb; + addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t)); + /* * We don't want to be preempted for the entire * duration of kprobe processing @@ -418,7 +425,7 @@ int __kprobes kprobe_handler(struct pt_regs *regs) if (kcb->kprobe_status == KPROBE_HIT_SS && *p->ainsn.insn == BREAKPOINT_INSTRUCTION) { regs->flags &= ~TF_MASK; - regs->flags |= kcb->kprobe_saved_rflags; + regs->flags |= kcb->kprobe_saved_flags; goto no_kprobe; } else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) { /* TODO: Provide re-entrancy from @@ -429,22 +436,20 @@ int __kprobes kprobe_handler(struct pt_regs *regs) arch_disarm_kprobe(p); regs->ip = (unsigned long)p->addr; reset_current_kprobe(); - ret = 1; - } else { - /* We have reentered the kprobe_handler(), since - * another probe was hit while within the - * handler. We here save the original kprobe - * variables and just single step on instruction - * of the new probe without calling any user - * handlers. - */ - save_previous_kprobe(kcb); - set_current_kprobe(p, regs, kcb); - kprobes_inc_nmissed_count(p); - prepare_singlestep(p, regs); - kcb->kprobe_status = KPROBE_REENTER; return 1; } + /* We have reentered the kprobe_handler(), since + * another probe was hit while within the handler. + * We here save the original kprobes variables and + * just single step on the instruction of the new probe + * without calling any user handlers. + */ + save_previous_kprobe(kcb); + set_current_kprobe(p, regs, kcb); + kprobes_inc_nmissed_count(p); + prepare_singlestep(p, regs); + kcb->kprobe_status = KPROBE_REENTER; + return 1; } else { if (*addr != BREAKPOINT_INSTRUCTION) { /* The breakpoint instruction was removed by @@ -578,23 +583,23 @@ fastcall void * __kprobes trampoline_handler(struct pt_regs *regs) INIT_HLIST_HEAD(&empty_rp); spin_lock_irqsave(&kretprobe_lock, flags); head = kretprobe_inst_table_head(current); - /* fixup rt_regs */ + /* fixup registers */ regs->cs = __KERNEL_CS; regs->ip = trampoline_address; - regs->orig_ax = 0xffffffffffffffff; + regs->orig_ax = ~0UL; /* * It is possible to have multiple instances associated with a given - * task either because an multiple functions in the call path - * have a return probe installed on them, and/or more then one return + * task either because multiple functions in the call path have + * return probes installed on them, and/or more then one * return probe was registered for a target function. * * We can handle this because: - * - instances are always inserted at the head of the list + * - instances are always pushed into the head of the list * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to the - * real return address, and all the rest will point to - * kretprobe_trampoline + * function, the (chronologically) first instance's ret_addr + * will be the real return address, and all the rest will + * point to kretprobe_trampoline. */ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { if (ri->task != current) @@ -661,9 +666,9 @@ fastcall void * __kprobes trampoline_handler(struct pt_regs *regs) static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { - unsigned long *tos = (unsigned long *)regs->sp; - unsigned long copy_rip = (unsigned long)p->ainsn.insn; - unsigned long orig_rip = (unsigned long)p->addr; + unsigned long *tos = stack_addr(regs); + unsigned long copy_ip = (unsigned long)p->ainsn.insn; + unsigned long orig_ip = (unsigned long)p->addr; kprobe_opcode_t *insn = p->ainsn.insn; /*skip the REX prefix*/ @@ -674,7 +679,7 @@ static void __kprobes resume_execution(struct kprobe *p, switch (*insn) { case 0x9c: /* pushfl */ *tos &= ~(TF_MASK | IF_MASK); - *tos |= kcb->kprobe_old_rflags; + *tos |= kcb->kprobe_old_flags; break; case 0xc2: /* iret/ret/lret */ case 0xc3: @@ -686,18 +691,23 @@ static void __kprobes resume_execution(struct kprobe *p, p->ainsn.boostable = 1; goto no_change; case 0xe8: /* call relative - Fix return addr */ - *tos = orig_rip + (*tos - copy_rip); + *tos = orig_ip + (*tos - copy_ip); break; case 0xff: if ((insn[1] & 0x30) == 0x10) { - /* call absolute, indirect */ - /* Fix return addr; ip is correct. */ - /* not boostable */ - *tos = orig_rip + (*tos - copy_rip); + /* + * call absolute, indirect + * Fix return addr; ip is correct. + * But this is not boostable + */ + *tos = orig_ip + (*tos - copy_ip); goto no_change; - } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */ - ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */ - /* ip is correct. And this is boostable */ + } else if (((insn[1] & 0x31) == 0x20) || + ((insn[1] & 0x31) == 0x21)) { + /* + * jmp near and far, absolute indirect + * ip is correct. And this is boostable + */ p->ainsn.boostable = 1; goto no_change; } @@ -706,21 +716,21 @@ static void __kprobes resume_execution(struct kprobe *p, } if (p->ainsn.boostable == 0) { - if ((regs->ip > copy_rip) && - (regs->ip - copy_rip) + 5 < MAX_INSN_SIZE) { + if ((regs->ip > copy_ip) && + (regs->ip - copy_ip) + 5 < MAX_INSN_SIZE) { /* * These instructions can be executed directly if it * jumps back to correct address. */ set_jmp_op((void *)regs->ip, - (void *)orig_rip + (regs->ip - copy_rip)); + (void *)orig_ip + (regs->ip - copy_ip)); p->ainsn.boostable = 1; } else { p->ainsn.boostable = -1; } } - regs->ip = orig_rip + (regs->ip - copy_rip); + regs->ip += orig_ip - copy_ip; no_change: restore_btf(); @@ -728,7 +738,11 @@ no_change: return; } -int __kprobes post_kprobe_handler(struct pt_regs *regs) +/* + * Interrupts are disabled on entry as trap1 is an interrupt gate and they + * remain disabled thoroughout this function. + */ +static int __kprobes post_kprobe_handler(struct pt_regs *regs) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); @@ -742,10 +756,10 @@ int __kprobes post_kprobe_handler(struct pt_regs *regs) } resume_execution(cur, regs, kcb); - regs->flags |= kcb->kprobe_saved_rflags; + regs->flags |= kcb->kprobe_saved_flags; trace_hardirqs_fixup_flags(regs->flags); - /* Restore the original saved kprobes variables and continue. */ + /* Restore back the original saved kprobes variables and continue. */ if (kcb->kprobe_status == KPROBE_REENTER) { restore_previous_kprobe(kcb); goto out; @@ -782,7 +796,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) * normal page fault. */ regs->ip = (unsigned long)cur->addr; - regs->flags |= kcb->kprobe_old_rflags; + regs->flags |= kcb->kprobe_old_flags; if (kcb->kprobe_status == KPROBE_REENTER) restore_previous_kprobe(kcb); else @@ -793,7 +807,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) case KPROBE_HIT_SSDONE: /* * We increment the nmissed count for accounting, - * we can also use npre/npostfault count for accouting + * we can also use npre/npostfault count for accounting * these specific fault cases. */ kprobes_inc_nmissed_count(cur); @@ -819,7 +833,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) } /* - * fixup() could not handle it, + * fixup routine could not handle it, * Let do_page_fault() fix it. */ break; @@ -838,7 +852,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - if (args->regs && user_mode(args->regs)) + if (args->regs && user_mode_vm(args->regs)) return ret; switch (val) { @@ -871,8 +885,9 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); kcb->jprobe_saved_regs = *regs; - kcb->jprobe_saved_rsp = (long *) regs->sp; - addr = (unsigned long)(kcb->jprobe_saved_rsp); + kcb->jprobe_saved_sp = stack_addr(regs); + addr = (unsigned long)(kcb->jprobe_saved_sp); + /* * As Linus pointed out, gcc assumes that the callee * owns the argument space and could overwrite it, e.g. @@ -897,21 +912,20 @@ void __kprobes jprobe_return(void) " .globl jprobe_return_end \n" " jprobe_return_end: \n" " nop \n"::"b" - (kcb->jprobe_saved_rsp):"memory"); + (kcb->jprobe_saved_sp):"memory"); } int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); u8 *addr = (u8 *) (regs->ip - 1); - unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_rsp); struct jprobe *jp = container_of(p, struct jprobe, kp); if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) { - if ((unsigned long *)regs->sp != kcb->jprobe_saved_rsp) { + if (stack_addr(regs) != kcb->jprobe_saved_sp) { struct pt_regs *saved_regs = &kcb->jprobe_saved_regs; printk("current sp %p does not match saved sp %p\n", - (long *)regs->sp, kcb->jprobe_saved_rsp); + stack_addr(regs), kcb->jprobe_saved_sp); printk("Saved registers for jprobe %p\n", jp); show_registers(saved_regs); printk("Current registers\n"); @@ -919,8 +933,9 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) BUG(); } *regs = kcb->jprobe_saved_regs; - memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack, - MIN_STACK_SIZE(stack_addr)); + memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp), + kcb->jprobes_stack, + MIN_STACK_SIZE(kcb->jprobe_saved_sp)); preempt_enable_no_resched(); return 1; } diff --git a/arch/x86/mm/fault_32.c b/arch/x86/mm/fault_32.c index 8aed912..db8d748 100644 --- a/arch/x86/mm/fault_32.c +++ b/arch/x86/mm/fault_32.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c index 88a7abd..162050d 100644 --- a/arch/x86/mm/fault_64.c +++ b/arch/x86/mm/fault_64.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include diff --git a/include/asm-x86/kprobes_32.h b/include/asm-x86/kprobes_32.h index 2f38315..94dff09 100644 --- a/include/asm-x86/kprobes_32.h +++ b/include/asm-x86/kprobes_32.h @@ -2,7 +2,6 @@ #define _ASM_KPROBES_H /* * Kernel Probes (KProbes) - * include/asm-i386/kprobes.h * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -23,14 +22,17 @@ * 2002-Oct Created by Vamsi Krishna S Kernel * Probes initial implementation ( includes suggestions from * Rusty Russell). + * 2004-Oct Prasanna S Panchamukhi and Jim Keniston + * kenistoj@us.ibm.com adopted from i386. */ #include #include +#include #define __ARCH_WANT_KPROBES_INSN_SLOT -struct kprobe; struct pt_regs; +struct kprobe; typedef u8 kprobe_opcode_t; #define BREAKPOINT_INSTRUCTION 0xcc @@ -38,9 +40,11 @@ typedef u8 kprobe_opcode_t; #define MAX_INSN_SIZE 16 #define MAX_STACK_SIZE 64 #define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \ - (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \ + (((unsigned long)current_thread_info()) + THREAD_SIZE \ + - (unsigned long)(ADDR))) \ ? (MAX_STACK_SIZE) \ - : (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) + : (((unsigned long)current_thread_info()) + THREAD_SIZE \ + - (unsigned long)(ADDR))) #define ARCH_SUPPORTS_KRETPROBES #define flush_insn_slot(p) do { } while (0) @@ -55,8 +59,12 @@ struct arch_specific_insn { /* copy of the original instruction */ kprobe_opcode_t *insn; /* - * If this flag is not 0, this kprobe can be boost when its - * post_handler and break_handler is not set. + * boostable = -1: This instruction type is not boostable. + * boostable = 0: This instruction type is boostable. + * boostable = 1: This instruction has been boosted: we have + * added a relative jump after the instruction copy in insn, + * so no single-step and fixup are needed (unless there's + * a post_handler or break_handler). */ int boostable; }; @@ -64,16 +72,16 @@ struct arch_specific_insn { struct prev_kprobe { struct kprobe *kp; unsigned long status; - unsigned long old_eflags; - unsigned long saved_eflags; + unsigned long old_flags; + unsigned long saved_flags; }; /* per-cpu kprobe control block */ struct kprobe_ctlblk { unsigned long kprobe_status; - unsigned long kprobe_old_eflags; - unsigned long kprobe_saved_eflags; - unsigned long *jprobe_saved_esp; + unsigned long kprobe_old_flags; + unsigned long kprobe_saved_flags; + unsigned long *jprobe_saved_sp; struct pt_regs jprobe_saved_regs; kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE]; struct prev_kprobe prev_kprobe; @@ -88,7 +96,7 @@ static inline void restore_interrupts(struct pt_regs *regs) local_irq_enable(); } +extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); extern int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); -extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); #endif /* _ASM_KPROBES_H */ diff --git a/include/asm-x86/kprobes_64.h b/include/asm-x86/kprobes_64.h index e7e921d..94dff09 100644 --- a/include/asm-x86/kprobes_64.h +++ b/include/asm-x86/kprobes_64.h @@ -2,7 +2,6 @@ #define _ASM_KPROBES_H /* * Kernel Probes (KProbes) - * include/asm-x86_64/kprobes.h * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -20,6 +19,9 @@ * * Copyright (C) IBM Corporation, 2002, 2004 * + * 2002-Oct Created by Vamsi Krishna S Kernel + * Probes initial implementation ( includes suggestions from + * Rusty Russell). * 2004-Oct Prasanna S Panchamukhi and Jim Keniston * kenistoj@us.ibm.com adopted from i386. */ @@ -35,19 +37,22 @@ struct kprobe; typedef u8 kprobe_opcode_t; #define BREAKPOINT_INSTRUCTION 0xcc #define RELATIVEJUMP_INSTRUCTION 0xe9 -#define MAX_INSN_SIZE 15 +#define MAX_INSN_SIZE 16 #define MAX_STACK_SIZE 64 #define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \ - (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \ + (((unsigned long)current_thread_info()) + THREAD_SIZE \ + - (unsigned long)(ADDR))) \ ? (MAX_STACK_SIZE) \ - : (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) + : (((unsigned long)current_thread_info()) + THREAD_SIZE \ + - (unsigned long)(ADDR))) #define ARCH_SUPPORTS_KRETPROBES +#define flush_insn_slot(p) do { } while (0) + extern const int kretprobe_blacklist_size; +void arch_remove_kprobe(struct kprobe *p); void kretprobe_trampoline(void); -extern void arch_remove_kprobe(struct kprobe *p); -#define flush_insn_slot(p) do { } while (0) /* Architecture specific copy of original instruction*/ struct arch_specific_insn { @@ -67,16 +72,16 @@ struct arch_specific_insn { struct prev_kprobe { struct kprobe *kp; unsigned long status; - unsigned long old_rflags; - unsigned long saved_rflags; + unsigned long old_flags; + unsigned long saved_flags; }; /* per-cpu kprobe control block */ struct kprobe_ctlblk { unsigned long kprobe_status; - unsigned long kprobe_old_rflags; - unsigned long kprobe_saved_rflags; - unsigned long *jprobe_saved_rsp; + unsigned long kprobe_old_flags; + unsigned long kprobe_saved_flags; + unsigned long *jprobe_saved_sp; struct pt_regs jprobe_saved_regs; kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE]; struct prev_kprobe prev_kprobe; @@ -91,10 +96,7 @@ static inline void restore_interrupts(struct pt_regs *regs) local_irq_enable(); } -extern int post_kprobe_handler(struct pt_regs *regs); extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); -extern int kprobe_handler(struct pt_regs *regs); - extern int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); #endif /* _ASM_KPROBES_H */ -- 2.7.4