diff options
author | Masami Hiramatsu <mhiramat@redhat.com> | 2008-01-30 13:31:21 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:31:21 +0100 |
commit | d6be29b871e285d33be0e3025929e2d6bcabb0c0 (patch) | |
tree | 5dbcd8ef953d19e3978062d337c76e4fa103150b /arch | |
parent | 8533bbe9f87b01f49ff951f665ea1988252fa3c2 (diff) | |
download | linux-d6be29b871e285d33be0e3025929e2d6bcabb0c0.tar.bz2 |
x86: kprobes code for x86 unification
This patch unifies kprobes code.
- Unify kprobes_*.h to kprobes.h
- Unify kprobes_*.c to kprobes.c
(Differences are separated by ifdefs)
- Most differences are related to REX prefix and rip relatives.
- Two inline assembly code are different.
- One difference in kprobe_handlre()
- One fixup exception code is different, but it will be unified
if mm/extable_*.c are unified.
- Merge history logs into arch/x86/kernel/kprobes.c.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/Makefile_32 | 2 | ||||
-rw-r--r-- | arch/x86/kernel/Makefile_64 | 2 | ||||
-rw-r--r-- | arch/x86/kernel/kprobes.c (renamed from arch/x86/kernel/kprobes_64.c) | 164 | ||||
-rw-r--r-- | arch/x86/kernel/kprobes_32.c | 848 |
4 files changed, 130 insertions, 886 deletions
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32 index a854e23eac0b..c7a959da363a 100644 --- a/arch/x86/kernel/Makefile_32 +++ b/arch/x86/kernel/Makefile_32 @@ -35,7 +35,7 @@ obj-$(CONFIG_KEXEC) += machine_kexec_32.o relocate_kernel_32.o crash.o obj-$(CONFIG_CRASH_DUMP) += crash_dump_32.o obj-$(CONFIG_X86_NUMAQ) += numaq_32.o obj-$(CONFIG_X86_SUMMIT_NUMA) += summit_32.o -obj-$(CONFIG_KPROBES) += kprobes_32.o +obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_MODULES) += module_32.o obj-$(CONFIG_ACPI_SRAT) += srat_32.o obj-$(CONFIG_EFI) += efi.o efi_32.o efi_stub_32.o diff --git a/arch/x86/kernel/Makefile_64 b/arch/x86/kernel/Makefile_64 index e5093dd8cf01..fbb370071239 100644 --- a/arch/x86/kernel/Makefile_64 +++ b/arch/x86/kernel/Makefile_64 @@ -34,7 +34,7 @@ obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_GART_IOMMU) += pci-gart_64.o aperture_64.o obj-$(CONFIG_CALGARY_IOMMU) += pci-calgary_64.o tce_64.o obj-$(CONFIG_SWIOTLB) += pci-swiotlb_64.o -obj-$(CONFIG_KPROBES) += kprobes_64.o +obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_X86_PM_TIMER) += pmtimer_64.o obj-$(CONFIG_X86_VSMP) += vsmp_64.o obj-$(CONFIG_K8_NB) += k8.o diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes.c index 2d7763749b1b..9aadd4d4a229 100644 --- a/arch/x86/kernel/kprobes_64.c +++ b/arch/x86/kernel/kprobes.c @@ -22,14 +22,22 @@ * Rusty Russell). * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes * interface to access function arguments. - * 2004-Oct Jim Keniston <kenistoj@us.ibm.com> and Prasanna S Panchamukhi - * <prasanna@in.ibm.com> adapted for x86_64 + * 2004-Oct Jim Keniston <jkenisto@us.ibm.com> and Prasanna S Panchamukhi + * <prasanna@in.ibm.com> adapted for x86_64 from i386. * 2005-Mar Roland McGrath <roland@redhat.com> * Fixed to handle %rip-relative addressing mode correctly. - * 2005-May Rusty Lynch <rusty.lynch@intel.com> - * Added function return probes functionality + * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston + * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi + * <prasanna@in.ibm.com> added function-return probes. + * 2005-May Rusty Lynch <rusty.lynch@intel.com> + * Added function return probes functionality + * 2006-Feb Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> added + * kprobe-booster and kretprobe-booster for i386. * 2007-Dec Masami Hiramatsu <mhiramat@redhat.com> added kprobe-booster * and kretprobe-booster for x86-64 + * 2007-Dec Masami Hiramatsu <mhiramat@redhat.com>, Arjan van de Ven + * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com> + * unified x86 kprobes code. */ #include <linux/kprobes.h> @@ -51,7 +59,19 @@ void jprobe_return_end(void); DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); +#ifdef CONFIG_X86_64 #define stack_addr(regs) ((unsigned long *)regs->sp) +#else +/* + * "®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) +#endif #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) | \ @@ -151,8 +171,8 @@ static __always_inline void set_jmp_op(void *from, void *to) } /* - * returns non-zero if opcode is boostable. - * RIP relative instructions are adjusted at copying time + * Returns non-zero if opcode is boostable. + * RIP relative instructions are adjusted at copying time in 64 bits mode */ static __always_inline int can_boost(kprobe_opcode_t *opcodes) { @@ -173,8 +193,10 @@ retry: } switch (opcode & 0xf0) { +#ifdef CONFIG_X86_64 case 0x40: goto retry; /* REX prefix is boostable */ +#endif case 0x60: if (0x63 < opcode && opcode < 0x67) goto retry; /* prefixes */ @@ -206,7 +228,7 @@ retry: } /* - * returns non-zero if opcode modifies the interrupt flag. + * Returns non-zero if opcode modifies the interrupt flag. */ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) { @@ -217,16 +239,18 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) case 0x9d: /* popf/popfd */ return 1; } - +#ifdef CONFIG_X86_64 /* * 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); +#endif return 0; } +#ifdef CONFIG_X86_64 /* * Adjust the displacement if the instruction uses the %rip-relative * addressing mode. @@ -263,17 +287,20 @@ static void __kprobes fix_riprel(struct kprobe *p) if ((*insn & 0xf0) == 0x40) ++insn; - if (*insn == 0x0f) { /* Two-byte opcode. */ + if (*insn == 0x0f) { + /* Two-byte opcode. */ ++insn; need_modrm = test_bit(*insn, (unsigned long *)twobyte_has_modrm); - } else /* One-byte opcode. */ + } 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 */ + if ((modrm & 0xc7) == 0x05) { + /* %rip+disp32 addressing mode */ /* Displacement follows ModRM byte. */ ++insn; /* @@ -296,11 +323,14 @@ static void __kprobes fix_riprel(struct kprobe *p) } } } +#endif static void __kprobes arch_copy_kprobe(struct kprobe *p) { memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); +#ifdef CONFIG_X86_64 fix_riprel(p); +#endif if (can_boost(p->addr)) p->ainsn.boostable = 0; else @@ -365,13 +395,13 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, static __always_inline void clear_btf(void) { if (test_thread_flag(TIF_DEBUGCTLMSR)) - wrmsrl(MSR_IA32_DEBUGCTLMSR, 0); + wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0); } static __always_inline void restore_btf(void) { if (test_thread_flag(TIF_DEBUGCTLMSR)) - wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr); + wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0); } static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) @@ -427,6 +457,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) regs->flags &= ~TF_MASK; regs->flags |= kcb->kprobe_saved_flags; goto no_kprobe; +#ifdef CONFIG_X86_64 } else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) { /* TODO: Provide re-entrancy from * post_kprobes_handler() and avoid exception @@ -437,6 +468,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) regs->ip = (unsigned long)p->addr; reset_current_kprobe(); return 1; +#endif } /* We have reentered the kprobe_handler(), since * another probe was hit while within the handler. @@ -461,9 +493,8 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) goto no_kprobe; } p = __get_cpu_var(current_kprobe); - if (p->break_handler && p->break_handler(p, regs)) { + if (p->break_handler && p->break_handler(p, regs)) goto ss_probe; - } } goto no_kprobe; } @@ -519,8 +550,10 @@ no_kprobe: */ void __kprobes kretprobe_trampoline_holder(void) { - asm volatile ( ".global kretprobe_trampoline\n" + asm volatile ( + ".global kretprobe_trampoline\n" "kretprobe_trampoline: \n" +#ifdef CONFIG_X86_64 /* We don't bother saving the ss register */ " pushq %rsp\n" " pushfq\n" @@ -566,25 +599,64 @@ no_kprobe: /* Skip orig_ax, ip, cs */ " addq $24, %rsp\n" " popfq\n" +#else + " pushf\n" + /* + * Skip cs, ip, orig_ax. + * trampoline_handler() will plug in these values + */ + " subl $12, %esp\n" + " pushl %fs\n" + " pushl %ds\n" + " pushl %es\n" + " pushl %eax\n" + " pushl %ebp\n" + " pushl %edi\n" + " pushl %esi\n" + " pushl %edx\n" + " pushl %ecx\n" + " pushl %ebx\n" + " movl %esp, %eax\n" + " call trampoline_handler\n" + /* Move flags to cs */ + " movl 52(%esp), %edx\n" + " movl %edx, 48(%esp)\n" + /* Replace saved flags with true return address. */ + " movl %eax, 52(%esp)\n" + " popl %ebx\n" + " popl %ecx\n" + " popl %edx\n" + " popl %esi\n" + " popl %edi\n" + " popl %ebp\n" + " popl %eax\n" + /* Skip ip, orig_ax, es, ds, fs */ + " addl $20, %esp\n" + " popf\n" +#endif " ret\n"); } /* * Called from kretprobe_trampoline */ -fastcall 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; struct hlist_node *node, *tmp; unsigned long flags, orig_ret_address = 0; - unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; + unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; INIT_HLIST_HEAD(&empty_rp); spin_lock_irqsave(&kretprobe_lock, flags); head = kretprobe_inst_table_head(current); /* fixup registers */ +#ifdef CONFIG_X86_64 regs->cs = __KERNEL_CS; +#else + regs->cs = __KERNEL_CS | get_kernel_rpl(); +#endif regs->ip = trampoline_address; regs->orig_ax = ~0UL; @@ -671,9 +743,11 @@ static void __kprobes resume_execution(struct kprobe *p, unsigned long orig_ip = (unsigned long)p->addr; kprobe_opcode_t *insn = p->ainsn.insn; +#ifdef CONFIG_X86_64 /*skip the REX prefix*/ if (*insn >= 0x40 && *insn <= 0x4f) insn++; +#endif regs->flags &= ~TF_MASK; switch (*insn) { @@ -693,6 +767,11 @@ static void __kprobes resume_execution(struct kprobe *p, case 0xe8: /* call relative - Fix return addr */ *tos = orig_ip + (*tos - copy_ip); break; +#ifndef CONFIG_X86_64 + case 0x9a: /* call absolute -- same as call absolute, indirect */ + *tos = orig_ip + (*tos - copy_ip); + goto no_change; +#endif case 0xff: if ((insn[1] & 0x30) == 0x10) { /* @@ -783,9 +862,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - const struct exception_table_entry *fixup; - switch(kcb->kprobe_status) { + switch (kcb->kprobe_status) { case KPROBE_HIT_SS: case KPROBE_REENTER: /* @@ -826,12 +904,19 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) * In case the user-specified fault handler returned * zero, try to fix up. */ - fixup = search_exception_tables(regs->ip); - if (fixup) { - regs->ip = fixup->fixup; - return 1; +#ifdef CONFIG_X86_64 + { + const struct exception_table_entry *fixup; + fixup = search_exception_tables(regs->ip); + if (fixup) { + regs->ip = fixup->fixup; + return 1; + } } - +#else + if (fixup_exception(regs)) + return 1; +#endif /* * fixup routine could not handle it, * Let do_page_fault() fix it. @@ -896,7 +981,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) * the argument area. */ memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, - MIN_STACK_SIZE(addr)); + MIN_STACK_SIZE(addr)); regs->flags &= ~IF_MASK; trace_hardirqs_off(); regs->ip = (unsigned long)(jp->entry); @@ -907,12 +992,17 @@ void __kprobes jprobe_return(void) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - asm volatile (" xchg %%rbx,%%rsp \n" - " int3 \n" - " .globl jprobe_return_end \n" - " jprobe_return_end: \n" - " nop \n"::"b" - (kcb->jprobe_saved_sp):"memory"); + asm volatile ( +#ifdef CONFIG_X86_64 + " xchg %%rbx,%%rsp \n" +#else + " xchgl %%ebx,%%esp \n" +#endif + " int3 \n" + " .globl jprobe_return_end\n" + " jprobe_return_end: \n" + " nop \n"::"b" + (kcb->jprobe_saved_sp):"memory"); } int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) @@ -921,14 +1011,16 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) u8 *addr = (u8 *) (regs->ip - 1); struct jprobe *jp = container_of(p, struct jprobe, kp); - if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) { + if ((addr > (u8 *) jprobe_return) && + (addr < (u8 *) jprobe_return_end)) { 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", + printk(KERN_ERR + "current sp %p does not match saved sp %p\n", stack_addr(regs), kcb->jprobe_saved_sp); - printk("Saved registers for jprobe %p\n", jp); + printk(KERN_ERR "Saved registers for jprobe %p\n", jp); show_registers(saved_regs); - printk("Current registers\n"); + printk(KERN_ERR "Current registers\n"); show_registers(regs); BUG(); } diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c deleted file mode 100644 index 8e06431d8b03..000000000000 --- a/arch/x86/kernel/kprobes_32.c +++ /dev/null @@ -1,848 +0,0 @@ -/* - * Kernel Probes (KProbes) - * - * 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 - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * Copyright (C) IBM Corporation, 2002, 2004 - * - * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel - * Probes initial implementation ( includes contributions from - * Rusty Russell). - * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes - * interface to access function arguments. - * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston - * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi - * <prasanna@in.ibm.com> added function-return probes. - */ - -#include <linux/kprobes.h> -#include <linux/ptrace.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <linux/preempt.h> -#include <linux/module.h> -#include <linux/kdebug.h> - -#include <asm/cacheflush.h> -#include <asm/desc.h> -#include <asm/pgtable.h> -#include <asm/uaccess.h> -#include <asm/alternative.h> - -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.*/ - {NULL, NULL} /* Terminator */ -}; -const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist); - -/* 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; - s32 raddr; - } __attribute__((packed)) * jop; - jop = (struct __arch_jmp_op *)from; - jop->raddr = (s32)((long)(to) - ((long)(from) + 5)); - jop->op = RELATIVEJUMP_INSTRUCTION; -} - -/* - * returns non-zero if opcode is boostable. - */ -static __always_inline int can_boost(kprobe_opcode_t *opcodes) -{ - kprobe_opcode_t opcode; - kprobe_opcode_t *orig_opcodes = opcodes; - -retry: - if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) - return 0; - opcode = *(opcodes++); - - /* 2nd-byte opcode */ - if (opcode == 0x0f) { - if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1) - return 0; - return test_bit(*opcodes, - (unsigned long *)twobyte_is_boostable); - } - - switch (opcode & 0xf0) { - case 0x60: - if (0x63 < opcode && opcode < 0x67) - goto retry; /* prefixes */ - /* can't boost Address-size override and bound */ - return (opcode != 0x62 && opcode != 0x67); - case 0x70: - return 0; /* can't boost conditional jump */ - case 0xc0: - /* can't boost software-interruptions */ - return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf; - case 0xd0: - /* can boost AA* and XLAT */ - return (opcode == 0xd4 || opcode == 0xd5 || opcode == 0xd7); - case 0xe0: - /* can boost in/out and absolute jmps */ - return ((opcode & 0x04) || opcode == 0xea); - case 0xf0: - if ((opcode & 0x0c) == 0 && opcode != 0xf1) - goto retry; /* lock/rep(ne) prefix */ - /* 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 */ - /* CS override prefix and call are not boostable */ - return (opcode != 0x2e && opcode != 0x9a); - } -} - -/* - * returns non-zero if opcode modifies the interrupt flag. - */ -static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) -{ - switch (*insn) { - case 0xfa: /* cli */ - case 0xfb: /* sti */ - case 0xcf: /* iret/iretd */ - case 0x9d: /* popf/popfd */ - return 1; - } - 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 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); -} - -void __kprobes arch_disarm_kprobe(struct kprobe *p) -{ - text_poke(p->addr, &p->opcode, 1); -} - -void __kprobes arch_remove_kprobe(struct kprobe *p) -{ - mutex_lock(&kprobe_mutex); - free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1)); - mutex_unlock(&kprobe_mutex); -} - -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_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_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_flags = kcb->kprobe_old_flags - = (regs->flags & (TF_MASK | IF_MASK)); - if (is_IF_modifier(p->ainsn.insn)) - kcb->kprobe_saved_flags &= ~IF_MASK; -} - -static __always_inline void clear_btf(void) -{ - if (test_thread_flag(TIF_DEBUGCTLMSR)) - wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0); -} - -static __always_inline void restore_btf(void) -{ - if (test_thread_flag(TIF_DEBUGCTLMSR)) - wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0); -} - -static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) -{ - clear_btf(); - regs->flags |= TF_MASK; - regs->flags &= ~IF_MASK; - /*single step inline if the instruction is an int3*/ - if (p->opcode == BREAKPOINT_INSTRUCTION) - regs->ip = (unsigned long)p->addr; - else - regs->ip = (unsigned long)p->ainsn.insn; -} - -/* Called with kretprobe_lock held */ -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, - struct pt_regs *regs) -{ - 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; -} - -/* - * 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; - 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 - */ - preempt_disable(); - kcb = get_kprobe_ctlblk(); - - /* Check we're not actually recursing */ - if (kprobe_running()) { - p = get_kprobe(addr); - if (p) { - if (kcb->kprobe_status == KPROBE_HIT_SS && - *p->ainsn.insn == BREAKPOINT_INSTRUCTION) { - regs->flags &= ~TF_MASK; - regs->flags |= kcb->kprobe_saved_flags; - goto no_kprobe; - } - /* 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 - * another cpu right after we hit, no further - * handling of this interrupt is appropriate - */ - regs->ip = (unsigned long)addr; - ret = 1; - goto no_kprobe; - } - p = __get_cpu_var(current_kprobe); - if (p->break_handler && p->break_handler(p, regs)) { - goto ss_probe; - } - } - goto no_kprobe; - } - - p = get_kprobe(addr); - if (!p) { - if (*addr != BREAKPOINT_INSTRUCTION) { - /* - * The breakpoint instruction was removed right - * after we hit it. Another cpu has removed - * either a probepoint or a debugger breakpoint - * at this address. In either case, no further - * handling of this interrupt is appropriate. - * Back up over the (now missing) int3 and run - * the original instruction. - */ - regs->ip = (unsigned long)addr; - ret = 1; - } - /* Not one of ours: let kernel handle it */ - goto no_kprobe; - } - - set_current_kprobe(p, regs, kcb); - kcb->kprobe_status = KPROBE_HIT_ACTIVE; - - if (p->pre_handler && p->pre_handler(p, regs)) - /* handler has already set things up, so skip ss setup */ - return 1; - -ss_probe: -#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM) - 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; - preempt_enable_no_resched(); - return 1; - } -#endif - prepare_singlestep(p, regs); - kcb->kprobe_status = KPROBE_HIT_SS; - return 1; - -no_kprobe: - preempt_enable_no_resched(); - return ret; -} - -/* - * 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. - * trampoline_handler() will plug in these values - */ - " subl $12, %esp\n" - " pushl %fs\n" - " pushl %ds\n" - " pushl %es\n" - " pushl %eax\n" - " pushl %ebp\n" - " pushl %edi\n" - " pushl %esi\n" - " pushl %edx\n" - " pushl %ecx\n" - " pushl %ebx\n" - " movl %esp, %eax\n" - " call trampoline_handler\n" - /* Move flags to cs */ - " movl 52(%esp), %edx\n" - " movl %edx, 48(%esp)\n" - /* Replace saved flags with true return address. */ - " movl %eax, 52(%esp)\n" - " popl %ebx\n" - " popl %ecx\n" - " popl %edx\n" - " popl %esi\n" - " popl %edi\n" - " popl %ebp\n" - " popl %eax\n" - /* 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) -{ - struct kretprobe_instance *ri = NULL; - struct hlist_head *head, empty_rp; - struct hlist_node *node, *tmp; - unsigned long flags, orig_ret_address = 0; - unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; - - INIT_HLIST_HEAD(&empty_rp); - spin_lock_irqsave(&kretprobe_lock, flags); - head = kretprobe_inst_table_head(current); - /* fixup registers */ - regs->cs = __KERNEL_CS | get_kernel_rpl(); - regs->ip = trampoline_address; - regs->orig_ax = ~0UL; - - /* - * It is possible to have multiple instances associated with a given - * 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 pushed into the head of the list - * - when multiple return probes are registered for the same - * 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) { - __get_cpu_var(current_kprobe) = &ri->rp->kp; - get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; - ri->rp->handler(ri, regs); - __get_cpu_var(current_kprobe) = NULL; - } - - orig_ret_address = (unsigned long)ri->ret_addr; - recycle_rp_inst(ri, &empty_rp); - - if (orig_ret_address != trampoline_address) - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - break; - } - - 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; -} - -/* - * Called after single-stepping. p->addr is the address of the - * instruction whose first byte has been replaced by the "int 3" - * instruction. To avoid the SMP problems that can occur when we - * temporarily put back the original opcode to single-step, we - * single-stepped a copy of the instruction. The address of this - * copy is p->ainsn.insn. - * - * This function prepares to return from the post-single-step - * interrupt. We have to fix up the stack as follows: - * - * 0) Except in the case of absolute or indirect jump or call instructions, - * the new ip is relative to the copied instruction. We need to make - * it relative to the original instruction. - * - * 1) If the single-stepped instruction was pushfl, then the TF and IF - * flags are set in the just-pushed flags, and may need to be cleared. - * - * 2) If the single-stepped instruction was a call, the return address - * that is atop the stack is the address following the copied instruction. - * We need to make it the address following the original instruction. - * - * 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 = 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 (*insn) { - case 0x9c: /* pushfl */ - *tos &= ~(TF_MASK | IF_MASK); - *tos |= kcb->kprobe_old_flags; - break; - case 0xc2: /* iret/ret/lret */ - case 0xc3: - case 0xca: - case 0xcb: - case 0xcf: - 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_ip + (*tos - copy_ip); - break; - case 0x9a: /* call absolute -- same as call absolute, indirect */ - *tos = orig_ip + (*tos - copy_ip); - goto no_change; - case 0xff: - if ((insn[1] & 0x30) == 0x10) { - /* - * 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) || - ((insn[1] & 0x31) == 0x21)) { - /* - * jmp near and far, absolute indirect - * ip is correct. And this is boostable - */ - p->ainsn.boostable = 1; - goto no_change; - } - default: - break; - } - - if (p->ainsn.boostable == 0) { - 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_ip + (regs->ip - copy_ip)); - p->ainsn.boostable = 1; - } else { - p->ainsn.boostable = -1; - } - } - - regs->ip += orig_ip - copy_ip; - -no_change: - restore_btf(); - - return; -} - -/* - * 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(); - - if (!cur) - return 0; - - if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { - kcb->kprobe_status = KPROBE_HIT_SSDONE; - cur->post_handler(cur, regs, 0); - } - - resume_execution(cur, regs, kcb); - regs->flags |= kcb->kprobe_saved_flags; - trace_hardirqs_fixup_flags(regs->flags); - - /* Restore back the original saved kprobes variables and continue. */ - if (kcb->kprobe_status == KPROBE_REENTER) { - restore_previous_kprobe(kcb); - goto out; - } - reset_current_kprobe(); -out: - preempt_enable_no_resched(); - - /* - * if somebody else is singlestepping across a probe point, flags - * will have TF set, in which case, continue the remaining processing - * of do_debug, as if this is not a probe hit. - */ - if (regs->flags & TF_MASK) - return 0; - - return 1; -} - -int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) -{ - struct kprobe *cur = kprobe_running(); - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - - switch(kcb->kprobe_status) { - case KPROBE_HIT_SS: - case KPROBE_REENTER: - /* - * We are here because the instruction being single - * stepped caused a page fault. We reset the current - * kprobe and the ip points back to the probe address - * and allow the page fault handler to continue as a - * normal page fault. - */ - regs->ip = (unsigned long)cur->addr; - regs->flags |= kcb->kprobe_old_flags; - if (kcb->kprobe_status == KPROBE_REENTER) - restore_previous_kprobe(kcb); - else - reset_current_kprobe(); - preempt_enable_no_resched(); - break; - case KPROBE_HIT_ACTIVE: - case KPROBE_HIT_SSDONE: - /* - * We increment the nmissed count for accounting, - * we can also use npre/npostfault count for accounting - * these specific fault cases. - */ - kprobes_inc_nmissed_count(cur); - - /* - * We come here because instructions in the pre/post - * handler caused the page_fault, this could happen - * if handler tries to access user space by - * copy_from_user(), get_user() etc. Let the - * user-specified handler try to fix it first. - */ - if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) - return 1; - - /* - * In case the user-specified fault handler returned - * zero, try to fix up. - */ - if (fixup_exception(regs)) - return 1; - - /* - * fixup routine could not handle it, - * Let do_page_fault() fix it. - */ - break; - default: - break; - } - return 0; -} - -/* - * Wrapper routine for handling exceptions. - */ -int __kprobes kprobe_exceptions_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - struct die_args *args = (struct die_args *)data; - int ret = NOTIFY_DONE; - - if (args->regs && user_mode_vm(args->regs)) - return ret; - - switch (val) { - case DIE_INT3: - if (kprobe_handler(args->regs)) - ret = NOTIFY_STOP; - break; - case DIE_DEBUG: - if (post_kprobe_handler(args->regs)) - ret = NOTIFY_STOP; - break; - case DIE_GPF: - /* kprobe_running() needs smp_processor_id() */ - preempt_disable(); - if (kprobe_running() && - kprobe_fault_handler(args->regs, args->trapnr)) - ret = NOTIFY_STOP; - preempt_enable(); - break; - default: - break; - } - return ret; -} - -int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) -{ - struct jprobe *jp = container_of(p, struct jprobe, kp); - unsigned long addr; - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - - kcb->jprobe_saved_regs = *regs; - 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. - * tailcall optimization. So, to be absolutely safe - * we also save and restore enough stack bytes to cover - * the argument area. - */ - memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, - MIN_STACK_SIZE(addr)); - regs->flags &= ~IF_MASK; - trace_hardirqs_off(); - regs->ip = (unsigned long)(jp->entry); - return 1; -} - -void __kprobes jprobe_return(void) -{ - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - - asm volatile (" xchgl %%ebx,%%esp \n" - " int3 \n" - " .globl jprobe_return_end \n" - " jprobe_return_end: \n" - " nop \n"::"b" - (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); - struct jprobe *jp = container_of(p, struct jprobe, kp); - - if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) { - 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", - stack_addr(regs), kcb->jprobe_saved_sp); - printk("Saved registers for jprobe %p\n", jp); - show_registers(saved_regs); - printk("Current registers\n"); - show_registers(regs); - BUG(); - } - *regs = kcb->jprobe_saved_regs; - 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 __init arch_init_kprobes(void) -{ - return 0; -} - -int __kprobes arch_trampoline_kprobe(struct kprobe *p) -{ - return 0; -} |