diff options
| -rw-r--r-- | arch/x86/kernel/Makefile_32 | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/ptrace_32.c | 125 | ||||
| -rw-r--r-- | arch/x86/kernel/step.c | 14 |
3 files changed, 15 insertions, 125 deletions
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32 index 9a6577a746b..20e23c4c18b 100644 --- a/arch/x86/kernel/Makefile_32 +++ b/arch/x86/kernel/Makefile_32 @@ -11,6 +11,7 @@ obj-y := process_32.o signal_32.o entry_32.o traps_32.o irq_32.o \ quirks.o i8237.o topology.o alternative.o i8253.o tsc_32.o io_delay.o rtc.o obj-y += tls.o +obj-y += step.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += cpu/ obj-y += acpi/ diff --git a/arch/x86/kernel/ptrace_32.c b/arch/x86/kernel/ptrace_32.c index 1402a54ef61..b73960885c3 100644 --- a/arch/x86/kernel/ptrace_32.c +++ b/arch/x86/kernel/ptrace_32.c @@ -137,131 +137,6 @@ static unsigned long getreg(struct task_struct *child, return retval; } -#define LDT_SEGMENT 4 - -static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs) -{ - unsigned long addr, seg; - - addr = regs->eip; - seg = regs->xcs & 0xffff; - if (regs->eflags & VM_MASK) { - addr = (addr & 0xffff) + (seg << 4); - return addr; - } - - /* - * We'll assume that the code segments in the GDT - * are all zero-based. That is largely true: the - * TLS segments are used for data, and the PNPBIOS - * and APM bios ones we just ignore here. - */ - if (seg & LDT_SEGMENT) { - u32 *desc; - unsigned long base; - - seg &= ~7UL; - - mutex_lock(&child->mm->context.lock); - if (unlikely((seg >> 3) >= child->mm->context.size)) - addr = -1L; /* bogus selector, access would fault */ - else { - desc = child->mm->context.ldt + seg; - base = ((desc[0] >> 16) | - ((desc[1] & 0xff) << 16) | - (desc[1] & 0xff000000)); - - /* 16-bit code segment? */ - if (!((desc[1] >> 22) & 1)) - addr &= 0xffff; - addr += base; - } - mutex_unlock(&child->mm->context.lock); - } - return addr; -} - -static inline int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs) -{ - int i, copied; - unsigned char opcode[15]; - unsigned long addr = convert_eip_to_linear(child, regs); - - copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0); - for (i = 0; i < copied; i++) { - switch (opcode[i]) { - /* popf and iret */ - case 0x9d: case 0xcf: - return 1; - /* opcode and address size prefixes */ - case 0x66: case 0x67: - continue; - /* irrelevant prefixes (segment overrides and repeats) */ - case 0x26: case 0x2e: - case 0x36: case 0x3e: - case 0x64: case 0x65: - case 0xf0: case 0xf2: case 0xf3: - continue; - - /* - * pushf: NOTE! We should probably not let - * the user see the TF bit being set. But - * it's more pain than it's worth to avoid - * it, and a debugger could emulate this - * all in user space if it _really_ cares. - */ - case 0x9c: - default: - return 0; - } - } - return 0; -} - -void user_enable_single_step(struct task_struct *child) -{ - struct pt_regs *regs = get_child_regs(child); - - /* - * Always set TIF_SINGLESTEP - this guarantees that - * we single-step system calls etc.. This will also - * cause us to set TF when returning to user mode. - */ - set_tsk_thread_flag(child, TIF_SINGLESTEP); - - /* - * If TF was already set, don't do anything else - */ - if (regs->eflags & X86_EFLAGS_TF) - return; - - /* Set TF on the kernel stack.. */ - regs->eflags |= X86_EFLAGS_TF; - - /* - * ..but if TF is changed by the instruction we will trace, - * don't mark it as being "us" that set it, so that we - * won't clear it by hand later. - */ - if (is_setting_trap_flag(child, regs)) - return; - - child->ptrace |= PT_DTRACE; -} - -void user_disable_single_step(struct task_struct *child) -{ - /* Always clear TIF_SINGLESTEP... */ - clear_tsk_thread_flag(child, TIF_SINGLESTEP); - - /* But touch TF only if it was set by us.. */ - if (child->ptrace & PT_DTRACE) { - struct pt_regs *regs = get_child_regs(child); - regs->eflags &= ~X86_EFLAGS_TF; - child->ptrace &= ~PT_DTRACE; - } -} - /* * Called by kernel/ptrace.c when detaching.. * diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 6a93b93f91f..6732272e347 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -5,12 +5,24 @@ #include <linux/mm.h> #include <linux/ptrace.h> +#ifdef CONFIG_X86_32 +static +#endif unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs) { unsigned long addr, seg; +#ifdef CONFIG_X86_64 addr = regs->rip; seg = regs->cs & 0xffff; +#else + addr = regs->eip; + seg = regs->xcs & 0xffff; + if (regs->eflags & X86_EFLAGS_VM) { + addr = (addr & 0xffff) + (seg << 4); + return addr; + } +#endif /* * We'll assume that the code segments in the GDT @@ -69,12 +81,14 @@ static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs) case 0xf0: case 0xf2: case 0xf3: continue; +#ifdef CONFIG_X86_64 case 0x40 ... 0x4f: if (regs->cs != __USER_CS) /* 32-bit mode: register increment */ return 0; /* 64-bit mode: REX prefix */ continue; +#endif /* CHECKME: f2, f3 */ |