diff options
Diffstat (limited to 'arch/i386/kernel/ptrace_32.c')
| -rw-r--r-- | arch/i386/kernel/ptrace_32.c | 723 |
1 files changed, 0 insertions, 723 deletions
diff --git a/arch/i386/kernel/ptrace_32.c b/arch/i386/kernel/ptrace_32.c deleted file mode 100644 index 7c1b92522e9..00000000000 --- a/arch/i386/kernel/ptrace_32.c +++ /dev/null @@ -1,723 +0,0 @@ -/* ptrace.c */ -/* By Ross Biro 1/23/92 */ -/* - * Pentium III FXSR, SSE support - * Gareth Hughes <gareth@valinux.com>, May 2000 - */ - -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/errno.h> -#include <linux/ptrace.h> -#include <linux/user.h> -#include <linux/security.h> -#include <linux/audit.h> -#include <linux/seccomp.h> -#include <linux/signal.h> - -#include <asm/uaccess.h> -#include <asm/pgtable.h> -#include <asm/system.h> -#include <asm/processor.h> -#include <asm/i387.h> -#include <asm/debugreg.h> -#include <asm/ldt.h> -#include <asm/desc.h> - -/* - * does not yet catch signals sent when the child dies. - * in exit.c or in signal.c. - */ - -/* - * Determines which flags the user has access to [1 = access, 0 = no access]. - * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9). - * Also masks reserved bits (31-22, 15, 5, 3, 1). - */ -#define FLAG_MASK 0x00050dd5 - -/* set's the trap flag. */ -#define TRAP_FLAG 0x100 - -/* - * Offset of eflags on child stack.. - */ -#define EFL_OFFSET offsetof(struct pt_regs, eflags) - -static inline struct pt_regs *get_child_regs(struct task_struct *task) -{ - void *stack_top = (void *)task->thread.esp0; - return stack_top - sizeof(struct pt_regs); -} - -/* - * This routine will get a word off of the processes privileged stack. - * the offset is bytes into the pt_regs structure on the stack. - * This routine assumes that all the privileged stacks are in our - * data space. - */ -static inline int get_stack_long(struct task_struct *task, int offset) -{ - unsigned char *stack; - - stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs); - stack += offset; - return (*((int *)stack)); -} - -/* - * This routine will put a word on the processes privileged stack. - * the offset is bytes into the pt_regs structure on the stack. - * This routine assumes that all the privileged stacks are in our - * data space. - */ -static inline int put_stack_long(struct task_struct *task, int offset, - unsigned long data) -{ - unsigned char * stack; - - stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs); - stack += offset; - *(unsigned long *) stack = data; - return 0; -} - -static int putreg(struct task_struct *child, - unsigned long regno, unsigned long value) -{ - switch (regno >> 2) { - case GS: - if (value && (value & 3) != 3) - return -EIO; - child->thread.gs = value; - return 0; - case DS: - case ES: - case FS: - if (value && (value & 3) != 3) - return -EIO; - value &= 0xffff; - break; - case SS: - case CS: - if ((value & 3) != 3) - return -EIO; - value &= 0xffff; - break; - case EFL: - value &= FLAG_MASK; - value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK; - break; - } - if (regno > FS*4) - regno -= 1*4; - put_stack_long(child, regno, value); - return 0; -} - -static unsigned long getreg(struct task_struct *child, - unsigned long regno) -{ - unsigned long retval = ~0UL; - - switch (regno >> 2) { - case GS: - retval = child->thread.gs; - break; - case DS: - case ES: - case FS: - case SS: - case CS: - retval = 0xffff; - /* fall through */ - default: - if (regno > FS*4) - regno -= 1*4; - retval &= get_stack_long(child, regno); - } - 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; - - down(&child->mm->context.sem); - 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; - } - up(&child->mm->context.sem); - } - 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; -} - -static void set_singlestep(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 & TRAP_FLAG) - return; - - /* Set TF on the kernel stack.. */ - regs->eflags |= TRAP_FLAG; - - /* - * ..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; -} - -static void clear_singlestep(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 &= ~TRAP_FLAG; - child->ptrace &= ~PT_DTRACE; - } -} - -/* - * Called by kernel/ptrace.c when detaching.. - * - * Make sure the single step bit is not set. - */ -void ptrace_disable(struct task_struct *child) -{ - clear_singlestep(child); - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); -} - -/* - * Perform get_thread_area on behalf of the traced child. - */ -static int -ptrace_get_thread_area(struct task_struct *child, - int idx, struct user_desc __user *user_desc) -{ - struct user_desc info; - struct desc_struct *desc; - -/* - * Get the current Thread-Local Storage area: - */ - -#define GET_BASE(desc) ( \ - (((desc)->a >> 16) & 0x0000ffff) | \ - (((desc)->b << 16) & 0x00ff0000) | \ - ( (desc)->b & 0xff000000) ) - -#define GET_LIMIT(desc) ( \ - ((desc)->a & 0x0ffff) | \ - ((desc)->b & 0xf0000) ) - -#define GET_32BIT(desc) (((desc)->b >> 22) & 1) -#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3) -#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1) -#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1) -#define GET_PRESENT(desc) (((desc)->b >> 15) & 1) -#define GET_USEABLE(desc) (((desc)->b >> 20) & 1) - - if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) - return -EINVAL; - - desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; - - info.entry_number = idx; - info.base_addr = GET_BASE(desc); - info.limit = GET_LIMIT(desc); - info.seg_32bit = GET_32BIT(desc); - info.contents = GET_CONTENTS(desc); - info.read_exec_only = !GET_WRITABLE(desc); - info.limit_in_pages = GET_LIMIT_PAGES(desc); - info.seg_not_present = !GET_PRESENT(desc); - info.useable = GET_USEABLE(desc); - - if (copy_to_user(user_desc, &info, sizeof(info))) - return -EFAULT; - - return 0; -} - -/* - * Perform set_thread_area on behalf of the traced child. - */ -static int -ptrace_set_thread_area(struct task_struct *child, - int idx, struct user_desc __user *user_desc) -{ - struct user_desc info; - struct desc_struct *desc; - - if (copy_from_user(&info, user_desc, sizeof(info))) - return -EFAULT; - - if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) - return -EINVAL; - - desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; - if (LDT_empty(&info)) { - desc->a = 0; - desc->b = 0; - } else { - desc->a = LDT_entry_a(&info); - desc->b = LDT_entry_b(&info); - } - - return 0; -} - -long arch_ptrace(struct task_struct *child, long request, long addr, long data) -{ - struct user * dummy = NULL; - int i, ret; - unsigned long __user *datap = (unsigned long __user *)data; - - switch (request) { - /* when I and D space are separate, these will need to be fixed. */ - case PTRACE_PEEKTEXT: /* read word at location addr. */ - case PTRACE_PEEKDATA: - ret = generic_ptrace_peekdata(child, addr, data); - break; - - /* read the word at location addr in the USER area. */ - case PTRACE_PEEKUSR: { - unsigned long tmp; - - ret = -EIO; - if ((addr & 3) || addr < 0 || - addr > sizeof(struct user) - 3) - break; - - tmp = 0; /* Default return condition */ - if(addr < FRAME_SIZE*sizeof(long)) - tmp = getreg(child, addr); - if(addr >= (long) &dummy->u_debugreg[0] && - addr <= (long) &dummy->u_debugreg[7]){ - addr -= (long) &dummy->u_debugreg[0]; - addr = addr >> 2; - tmp = child->thread.debugreg[addr]; - } - ret = put_user(tmp, datap); - break; - } - - /* when I and D space are separate, this will have to be fixed. */ - case PTRACE_POKETEXT: /* write the word at location addr. */ - case PTRACE_POKEDATA: - ret = generic_ptrace_pokedata(child, addr, data); - break; - - case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ - ret = -EIO; - if ((addr & 3) || addr < 0 || - addr > sizeof(struct user) - 3) - break; - - if (addr < FRAME_SIZE*sizeof(long)) { - ret = putreg(child, addr, data); - break; - } - /* We need to be very careful here. We implicitly - want to modify a portion of the task_struct, and we - have to be selective about what portions we allow someone - to modify. */ - - ret = -EIO; - if(addr >= (long) &dummy->u_debugreg[0] && - addr <= (long) &dummy->u_debugreg[7]){ - - if(addr == (long) &dummy->u_debugreg[4]) break; - if(addr == (long) &dummy->u_debugreg[5]) break; - if(addr < (long) &dummy->u_debugreg[4] && - ((unsigned long) data) >= TASK_SIZE-3) break; - - /* Sanity-check data. Take one half-byte at once with - * check = (val >> (16 + 4*i)) & 0xf. It contains the - * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits - * 2 and 3 are LENi. Given a list of invalid values, - * we do mask |= 1 << invalid_value, so that - * (mask >> check) & 1 is a correct test for invalid - * values. - * - * R/Wi contains the type of the breakpoint / - * watchpoint, LENi contains the length of the watched - * data in the watchpoint case. - * - * The invalid values are: - * - LENi == 0x10 (undefined), so mask |= 0x0f00. - * - R/Wi == 0x10 (break on I/O reads or writes), so - * mask |= 0x4444. - * - R/Wi == 0x00 && LENi != 0x00, so we have mask |= - * 0x1110. - * - * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54. - * - * See the Intel Manual "System Programming Guide", - * 15.2.4 - * - * Note that LENi == 0x10 is defined on x86_64 in long - * mode (i.e. even for 32-bit userspace software, but - * 64-bit kernel), so the x86_64 mask value is 0x5454. - * See the AMD manual no. 24593 (AMD64 System - * Programming)*/ - - if(addr == (long) &dummy->u_debugreg[7]) { - data &= ~DR_CONTROL_RESERVED; - for(i=0; i<4; i++) - if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1) - goto out_tsk; - if (data) - set_tsk_thread_flag(child, TIF_DEBUG); - else - clear_tsk_thread_flag(child, TIF_DEBUG); - } - addr -= (long) &dummy->u_debugreg; - addr = addr >> 2; - child->thread.debugreg[addr] = data; - ret = 0; - } - break; - - case PTRACE_SYSEMU: /* continue and stop at next syscall, which will not be executed */ - case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ - case PTRACE_CONT: /* restart after signal. */ - ret = -EIO; - if (!valid_signal(data)) - break; - if (request == PTRACE_SYSEMU) { - set_tsk_thread_flag(child, TIF_SYSCALL_EMU); - clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); - } else if (request == PTRACE_SYSCALL) { - set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); - } else { - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); - clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); - } - child->exit_code = data; - /* make sure the single step bit is not set. */ - clear_singlestep(child); - wake_up_process(child); - ret = 0; - break; - -/* - * make the child exit. Best I can do is send it a sigkill. - * perhaps it should be put in the status that it wants to - * exit. - */ - case PTRACE_KILL: - ret = 0; - if (child->exit_state == EXIT_ZOMBIE) /* already dead */ - break; - child->exit_code = SIGKILL; - /* make sure the single step bit is not set. */ - clear_singlestep(child); - wake_up_process(child); - break; - - case PTRACE_SYSEMU_SINGLESTEP: /* Same as SYSEMU, but singlestep if not syscall */ - case PTRACE_SINGLESTEP: /* set the trap flag. */ - ret = -EIO; - if (!valid_signal(data)) - break; - - if (request == PTRACE_SYSEMU_SINGLESTEP) - set_tsk_thread_flag(child, TIF_SYSCALL_EMU); - else - clear_tsk_thread_flag(child, TIF_SYSCALL_EMU); - - clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); - set_singlestep(child); - child->exit_code = data; - /* give it a chance to run. */ - wake_up_process(child); - ret = 0; - break; - - case PTRACE_DETACH: - /* detach a process that was attached. */ - ret = ptrace_detach(child, data); - break; - - case PTRACE_GETREGS: { /* Get all gp regs from the child. */ - if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) { - ret = -EIO; - break; - } - for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) { - __put_user(getreg(child, i), datap); - datap++; - } - ret = 0; - break; - } - - case PTRACE_SETREGS: { /* Set all gp regs in the child. */ - unsigned long tmp; - if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) { - ret = -EIO; - break; - } - for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) { - __get_user(tmp, datap); - putreg(child, i, tmp); - datap++; - } - ret = 0; - break; - } - - case PTRACE_GETFPREGS: { /* Get the child FPU state. */ - if (!access_ok(VERIFY_WRITE, datap, - sizeof(struct user_i387_struct))) { - ret = -EIO; - break; - } - ret = 0; - if (!tsk_used_math(child)) - init_fpu(child); - get_fpregs((struct user_i387_struct __user *)data, child); - break; - } - - case PTRACE_SETFPREGS: { /* Set the child FPU state. */ - if (!access_ok(VERIFY_READ, datap, - sizeof(struct user_i387_struct))) { - ret = -EIO; - break; - } - set_stopped_child_used_math(child); - set_fpregs(child, (struct user_i387_struct __user *)data); - ret = 0; - break; - } - - case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */ - if (!access_ok(VERIFY_WRITE, datap, - sizeof(struct user_fxsr_struct))) { - ret = -EIO; - break; - } - if (!tsk_used_math(child)) - init_fpu(child); - ret = get_fpxregs((struct user_fxsr_struct __user *)data, child); - break; - } - - case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */ - if (!access_ok(VERIFY_READ, datap, - sizeof(struct user_fxsr_struct))) { - ret = -EIO; - break; - } - set_stopped_child_used_math(child); - ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data); - break; - } - - case PTRACE_GET_THREAD_AREA: - ret = ptrace_get_thread_area(child, addr, - (struct user_desc __user *) data); - break; - - case PTRACE_SET_THREAD_AREA: - ret = ptrace_set_thread_area(child, addr, - (struct user_desc __user *) data); - break; - - default: - ret = ptrace_request(child, request, addr, data); - break; - } - out_tsk: - return ret; -} - -void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) -{ - struct siginfo info; - - tsk->thread.trap_no = 1; - tsk->thread.error_code = error_code; - - memset(&info, 0, sizeof(info)); - info.si_signo = SIGTRAP; - info.si_code = TRAP_BRKPT; - - /* User-mode eip? */ - info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL; - - /* Send us the fakey SIGTRAP */ - force_sig_info(SIGTRAP, &info, tsk); -} - -/* notification of system call entry/exit - * - triggered by current->work.syscall_trace - */ -__attribute__((regparm(3))) -int do_syscall_trace(struct pt_regs *regs, int entryexit) -{ - int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU); - /* - * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall - * interception - */ - int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP); - int ret = 0; - - /* do the secure computing check first */ - if (!entryexit) - secure_computing(regs->orig_eax); - - if (unlikely(current->audit_context)) { - if (entryexit) - audit_syscall_exit(AUDITSC_RESULT(regs->eax), - regs->eax); - /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only - * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is - * not used, entry.S will call us only on syscall exit, not - * entry; so when TIF_SYSCALL_AUDIT is used we must avoid - * calling send_sigtrap() on syscall entry. - * - * Note that when PTRACE_SYSEMU_SINGLESTEP is used, - * is_singlestep is false, despite his name, so we will still do - * the correct thing. - */ - else if (is_singlestep) - goto out; - } - - if (!(current->ptrace & PT_PTRACED)) - goto out; - - /* If a process stops on the 1st tracepoint with SYSCALL_TRACE - * and then is resumed with SYSEMU_SINGLESTEP, it will come in - * here. We have to check this and return */ - if (is_sysemu && entryexit) - return 0; - - /* Fake a debug trap */ - if (is_singlestep) - send_sigtrap(current, regs, 0); - - if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu) - goto out; - - /* the 0x80 provides a way for the tracing parent to distinguish - between a syscall stop and SIGTRAP delivery */ - /* Note that the debugger could change the result of test_thread_flag!*/ - ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0)); - - /* - * this isn't the same as continuing with a signal, but it will do - * for normal use. strace only continues with a signal if the - * stopping signal is not SIGTRAP. -brl - */ - if (current->exit_code) { - send_sig(current->exit_code, current, 1); - current->exit_code = 0; - } - ret = is_sysemu; -out: - if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_eax, - regs->ebx, regs->ecx, regs->edx, regs->esi); - if (ret == 0) - return 0; - - regs->orig_eax = -1; /* force skip of syscall restarting */ - if (unlikely(current->audit_context)) - audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax); - return 1; -} |