diff options
author | Roland McGrath <roland@redhat.com> | 2008-01-30 13:30:50 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:50 +0100 |
commit | 7122ec8158b0f88befd94f4da8feae2c8d08d1b4 (patch) | |
tree | 17aa91add10e04cf27e93ba2b673fcb651ed39ba /arch/x86/kernel/ptrace_32.c | |
parent | 5f76cb1f6c42e7575256595f85b8b97d84ec669e (diff) |
x86: single_step: share code
This removes the single-step code from ptrace_32.c and uses the step.c code
shared with the 64-bit kernel. The two versions of the code were nearly
identical already, so the shared code has only a couple of simple #ifdef's.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/ptrace_32.c')
-rw-r--r-- | arch/x86/kernel/ptrace_32.c | 125 |
1 files changed, 0 insertions, 125 deletions
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.. * |