-/* ptrace.c */
/* By Ross Biro 1/23/92 */
/*
* Pentium III FXSR, SSE support
*/
#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)
+static long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
{
- 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;
+ BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
+ if (regno > FS)
+ --regno;
+ return ®s->bx + regno;
}
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;
+ struct pt_regs *regs = task_pt_regs(child);
+ regno >>= 2;
+ switch (regno) {
+ 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;
+ /*
+ * If the user value contains TF, mark that
+ * it was not "us" (the debugger) that set it.
+ * If not, make sure it stays set if we had.
+ */
+ if (value & X86_EFLAGS_TF)
+ clear_tsk_thread_flag(child, TIF_FORCED_TF);
+ else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
+ value |= X86_EFLAGS_TF;
+ value |= regs->flags & ~FLAG_MASK;
+ break;
}
- if (regno > FS*4)
- regno -= 1*4;
- put_stack_long(child, regno, value);
+ *pt_regs_access(regs, regno) = value;
return 0;
}
-static unsigned long getreg(struct task_struct *child,
- unsigned long regno)
+static unsigned long getreg(struct task_struct *child, unsigned long regno)
{
+ struct pt_regs *regs = task_pt_regs(child);
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);
+ regno >>= 2;
+ switch (regno) {
+ case EFL:
+ /*
+ * If the debugger set TF, hide it from the readout.
+ */
+ retval = regs->flags;
+ if (test_tsk_thread_flag(child, TIF_FORCED_TF))
+ retval &= ~X86_EFLAGS_TF;
+ break;
+ case GS:
+ retval = child->thread.gs;
+ break;
+ case DS:
+ case ES:
+ case FS:
+ case SS:
+ case CS:
+ retval = 0xffff;
+ /* fall through */
+ default:
+ retval &= *pt_regs_access(regs, regno);
}
return retval;
}
-#define LDT_SEGMENT 4
-
-static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs)
+/*
+ * This function is trivial and will be inlined by the compiler.
+ * Having it separates the implementation details of debug
+ * registers from the interface details of ptrace.
+ */
+static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
{
- 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;
+ return child->thread.debugreg[n];
}
-static inline int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs)
+static int ptrace_set_debugreg(struct task_struct *child,
+ int n, unsigned long data)
{
- 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;
+ if (unlikely(n == 4 || n == 5))
+ return -EIO;
+
+ if (n < 4 && unlikely(data >= TASK_SIZE - 3))
+ return -EIO;
+ if (n == 7) {
/*
- * 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.
+ * 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)
*/
- case 0x9c:
- default:
- return 0;
- }
+ int i;
+ data &= ~DR_CONTROL_RESERVED;
+ for (i = 0; i < 4; i++)
+ if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
+ return -EIO;
+ if (data)
+ set_tsk_thread_flag(child, TIF_DEBUG);
+ else
+ clear_tsk_thread_flag(child, TIF_DEBUG);
}
- 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;
-}
+ child->thread.debugreg[n] = data;
-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;
- }
+ return 0;
}
/*
* 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;
+ user_disable_single_step(child);
+ clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long 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_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
ret = generic_ptrace_peekdata(child, addr, data);
break;
unsigned long tmp;
ret = -EIO;
- if ((addr & 3) || addr < 0 ||
+ if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
addr <= (long) &dummy->u_debugreg[7]){
addr -= (long) &dummy->u_debugreg[0];
addr = addr >> 2;
- tmp = child->thread.debugreg[addr];
+ tmp = ptrace_get_debugreg(child, addr);
}
ret = put_user(tmp, datap);
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = -EIO;
- if ((addr & 3) || addr < 0 ||
+ if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
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;
+ ret = ptrace_set_debugreg(child, addr, data);
}
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;
}
case PTRACE_GET_THREAD_AREA:
- ret = ptrace_get_thread_area(child, addr,
- (struct user_desc __user *) data);
+ if (addr < 0)
+ return -EIO;
+ ret = do_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);
+ if (addr < 0)
+ return -EIO;
+ ret = do_set_thread_area(child, addr,
+ (struct user_desc __user *) data, 0);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
- out_tsk:
+
return ret;
}
info.si_signo = SIGTRAP;
info.si_code = TRAP_BRKPT;
- /* User-mode eip? */
- info.si_addr = user_mode_vm(regs) ? (void __user *) regs->eip : NULL;
+ /* User-mode ip? */
+ info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
- /* Send us the fakey SIGTRAP */
+ /* Send us the fake SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
}
/* do the secure computing check first */
if (!entryexit)
- secure_computing(regs->orig_eax);
+ secure_computing(regs->orig_ax);
if (unlikely(current->audit_context)) {
if (entryexit)
- audit_syscall_exit(AUDITSC_RESULT(regs->eax),
- regs->eax);
+ audit_syscall_exit(AUDITSC_RESULT(regs->ax),
+ regs->ax);
/* 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
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);
+ audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax,
+ regs->bx, regs->cx, regs->dx, regs->si);
if (ret == 0)
return 0;
- regs->orig_eax = -1; /* force skip of syscall restarting */
+ regs->orig_ax = -1; /* force skip of syscall restarting */
if (unlikely(current->audit_context))
- audit_syscall_exit(AUDITSC_RESULT(regs->eax), regs->eax);
+ audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
return 1;
}
projects / linux-2.6-omap-h63xx.git / blobdiff