#include <asm/system.h>
#include <asm/traps.h>
-#include "ptrace.h"
-
#define REG_PC 15
#define REG_PSR 16
/*
return ret;
}
-static inline int
-read_u32(struct task_struct *task, unsigned long addr, u32 *res)
-{
- int ret;
-
- ret = access_process_vm(task, addr, res, sizeof(*res), 0);
-
- return ret == sizeof(*res) ? 0 : -EIO;
-}
-
-static inline int
-read_instr(struct task_struct *task, unsigned long addr, u32 *res)
-{
- int ret;
-
- if (addr & 1) {
- u16 val;
- ret = access_process_vm(task, addr & ~1, &val, sizeof(val), 0);
- ret = ret == sizeof(val) ? 0 : -EIO;
- *res = val;
- } else {
- u32 val;
- ret = access_process_vm(task, addr & ~3, &val, sizeof(val), 0);
- ret = ret == sizeof(val) ? 0 : -EIO;
- *res = val;
- }
- return ret;
-}
-
-/*
- * Get value of register `rn' (in the instruction)
- */
-static unsigned long
-ptrace_getrn(struct task_struct *child, unsigned long insn)
-{
- unsigned int reg = (insn >> 16) & 15;
- unsigned long val;
-
- val = get_user_reg(child, reg);
- if (reg == 15)
- val += 8;
-
- return val;
-}
-
-/*
- * Get value of operand 2 (in an ALU instruction)
- */
-static unsigned long
-ptrace_getaluop2(struct task_struct *child, unsigned long insn)
-{
- unsigned long val;
- int shift;
- int type;
-
- if (insn & 1 << 25) {
- val = insn & 255;
- shift = (insn >> 8) & 15;
- type = 3;
- } else {
- val = get_user_reg (child, insn & 15);
-
- if (insn & (1 << 4))
- shift = (int)get_user_reg (child, (insn >> 8) & 15);
- else
- shift = (insn >> 7) & 31;
-
- type = (insn >> 5) & 3;
- }
-
- switch (type) {
- case 0: val <<= shift; break;
- case 1: val >>= shift; break;
- case 2:
- val = (((signed long)val) >> shift);
- break;
- case 3:
- val = (val >> shift) | (val << (32 - shift));
- break;
- }
- return val;
-}
-
-/*
- * Get value of operand 2 (in a LDR instruction)
- */
-static unsigned long
-ptrace_getldrop2(struct task_struct *child, unsigned long insn)
-{
- unsigned long val;
- int shift;
- int type;
-
- val = get_user_reg(child, insn & 15);
- shift = (insn >> 7) & 31;
- type = (insn >> 5) & 3;
-
- switch (type) {
- case 0: val <<= shift; break;
- case 1: val >>= shift; break;
- case 2:
- val = (((signed long)val) >> shift);
- break;
- case 3:
- val = (val >> shift) | (val << (32 - shift));
- break;
- }
- return val;
-}
-
-#define OP_MASK 0x01e00000
-#define OP_AND 0x00000000
-#define OP_EOR 0x00200000
-#define OP_SUB 0x00400000
-#define OP_RSB 0x00600000
-#define OP_ADD 0x00800000
-#define OP_ADC 0x00a00000
-#define OP_SBC 0x00c00000
-#define OP_RSC 0x00e00000
-#define OP_ORR 0x01800000
-#define OP_MOV 0x01a00000
-#define OP_BIC 0x01c00000
-#define OP_MVN 0x01e00000
-
-static unsigned long
-get_branch_address(struct task_struct *child, unsigned long pc, unsigned long insn)
-{
- u32 alt = 0;
-
- switch (insn & 0x0e000000) {
- case 0x00000000:
- case 0x02000000: {
- /*
- * data processing
- */
- long aluop1, aluop2, ccbit;
-
- if ((insn & 0x0fffffd0) == 0x012fff10) {
- /*
- * bx or blx
- */
- alt = get_user_reg(child, insn & 15);
- break;
- }
-
-
- if ((insn & 0xf000) != 0xf000)
- break;
-
- aluop1 = ptrace_getrn(child, insn);
- aluop2 = ptrace_getaluop2(child, insn);
- ccbit = get_user_reg(child, REG_PSR) & PSR_C_BIT ? 1 : 0;
-
- switch (insn & OP_MASK) {
- case OP_AND: alt = aluop1 & aluop2; break;
- case OP_EOR: alt = aluop1 ^ aluop2; break;
- case OP_SUB: alt = aluop1 - aluop2; break;
- case OP_RSB: alt = aluop2 - aluop1; break;
- case OP_ADD: alt = aluop1 + aluop2; break;
- case OP_ADC: alt = aluop1 + aluop2 + ccbit; break;
- case OP_SBC: alt = aluop1 - aluop2 + ccbit; break;
- case OP_RSC: alt = aluop2 - aluop1 + ccbit; break;
- case OP_ORR: alt = aluop1 | aluop2; break;
- case OP_MOV: alt = aluop2; break;
- case OP_BIC: alt = aluop1 & ~aluop2; break;
- case OP_MVN: alt = ~aluop2; break;
- }
- break;
- }
-
- case 0x04000000:
- case 0x06000000:
- /*
- * ldr
- */
- if ((insn & 0x0010f000) == 0x0010f000) {
- unsigned long base;
-
- base = ptrace_getrn(child, insn);
- if (insn & 1 << 24) {
- long aluop2;
-
- if (insn & 0x02000000)
- aluop2 = ptrace_getldrop2(child, insn);
- else
- aluop2 = insn & 0xfff;
-
- if (insn & 1 << 23)
- base += aluop2;
- else
- base -= aluop2;
- }
- read_u32(child, base, &alt);
- }
- break;
-
- case 0x08000000:
- /*
- * ldm
- */
- if ((insn & 0x00108000) == 0x00108000) {
- unsigned long base;
- unsigned int nr_regs;
-
- if (insn & (1 << 23)) {
- nr_regs = hweight16(insn & 65535) << 2;
-
- if (!(insn & (1 << 24)))
- nr_regs -= 4;
- } else {
- if (insn & (1 << 24))
- nr_regs = -4;
- else
- nr_regs = 0;
- }
-
- base = ptrace_getrn(child, insn);
-
- read_u32(child, base + nr_regs, &alt);
- break;
- }
- break;
-
- case 0x0a000000: {
- /*
- * bl or b
- */
- signed long displ;
- /* It's a branch/branch link: instead of trying to
- * figure out whether the branch will be taken or not,
- * we'll put a breakpoint at both locations. This is
- * simpler, more reliable, and probably not a whole lot
- * slower than the alternative approach of emulating the
- * branch.
- */
- displ = (insn & 0x00ffffff) << 8;
- displ = (displ >> 6) + 8;
- if (displ != 0 && displ != 4)
- alt = pc + displ;
- }
- break;
- }
-
- return alt;
-}
-
-static int
-swap_insn(struct task_struct *task, unsigned long addr,
- void *old_insn, void *new_insn, int size)
-{
- int ret;
-
- ret = access_process_vm(task, addr, old_insn, size, 0);
- if (ret == size)
- ret = access_process_vm(task, addr, new_insn, size, 1);
- return ret;
-}
-
-static void
-add_breakpoint(struct task_struct *task, struct debug_info *dbg, unsigned long addr)
-{
- int nr = dbg->nsaved;
-
- if (nr < 2) {
- u32 new_insn = BREAKINST_ARM;
- int res;
-
- res = swap_insn(task, addr, &dbg->bp[nr].insn, &new_insn, 4);
-
- if (res == 4) {
- dbg->bp[nr].address = addr;
- dbg->nsaved += 1;
- }
- } else
- printk(KERN_ERR "ptrace: too many breakpoints\n");
-}
-
-/*
- * Clear one breakpoint in the user program. We copy what the hardware
- * does and use bit 0 of the address to indicate whether this is a Thumb
- * breakpoint or an ARM breakpoint.
- */
-static void clear_breakpoint(struct task_struct *task, struct debug_entry *bp)
-{
- unsigned long addr = bp->address;
- union debug_insn old_insn;
- int ret;
-
- if (addr & 1) {
- ret = swap_insn(task, addr & ~1, &old_insn.thumb,
- &bp->insn.thumb, 2);
-
- if (ret != 2 || old_insn.thumb != BREAKINST_THUMB)
- printk(KERN_ERR "%s:%d: corrupted Thumb breakpoint at "
- "0x%08lx (0x%04x)\n", task->comm,
- task_pid_nr(task), addr, old_insn.thumb);
- } else {
- ret = swap_insn(task, addr & ~3, &old_insn.arm,
- &bp->insn.arm, 4);
-
- if (ret != 4 || old_insn.arm != BREAKINST_ARM)
- printk(KERN_ERR "%s:%d: corrupted ARM breakpoint at "
- "0x%08lx (0x%08x)\n", task->comm,
- task_pid_nr(task), addr, old_insn.arm);
- }
-}
-
-void ptrace_set_bpt(struct task_struct *child)
-{
- struct pt_regs *regs;
- unsigned long pc;
- u32 insn;
- int res;
-
- regs = task_pt_regs(child);
- pc = instruction_pointer(regs);
-
- if (thumb_mode(regs)) {
- printk(KERN_WARNING "ptrace: can't handle thumb mode\n");
- return;
- }
-
- res = read_instr(child, pc, &insn);
- if (!res) {
- struct debug_info *dbg = &child->thread.debug;
- unsigned long alt;
-
- dbg->nsaved = 0;
-
- alt = get_branch_address(child, pc, insn);
- if (alt)
- add_breakpoint(child, dbg, alt);
-
- /*
- * Note that we ignore the result of setting the above
- * breakpoint since it may fail. When it does, this is
- * not so much an error, but a forewarning that we may
- * be receiving a prefetch abort shortly.
- *
- * If we don't set this breakpoint here, then we can
- * lose control of the thread during single stepping.
- */
- if (!alt || predicate(insn) != PREDICATE_ALWAYS)
- add_breakpoint(child, dbg, pc + 4);
- }
-}
-
-/*
- * Ensure no single-step breakpoint is pending. Returns non-zero
- * value if child was being single-stepped.
- */
-void ptrace_cancel_bpt(struct task_struct *child)
-{
- int i, nsaved = child->thread.debug.nsaved;
-
- child->thread.debug.nsaved = 0;
-
- if (nsaved > 2) {
- printk("ptrace_cancel_bpt: bogus nsaved: %d!\n", nsaved);
- nsaved = 2;
- }
-
- for (i = 0; i < nsaved; i++)
- clear_breakpoint(child, &child->thread.debug.bp[i]);
-}
-
-void user_disable_single_step(struct task_struct *task)
-{
- task->ptrace &= ~PT_SINGLESTEP;
- ptrace_cancel_bpt(task);
-}
-
-void user_enable_single_step(struct task_struct *task)
-{
- task->ptrace |= PT_SINGLESTEP;
-}
-
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
- user_disable_single_step(child);
+ /* Nothing to do. */
}
/*
{
siginfo_t info;
- ptrace_cancel_bpt(tsk);
-
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_BRKPT;
git.openpandora.org / pandora-kernel.git / blobdiff