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yaml
---
r: 258355
b: refs/heads/master
c: 235a4ce
h: refs/heads/master
i:
  258353: 5e578ce
  258351: f248da7
v: v3
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Jon Medhurst authored and Tixy committed Jul 13, 2011
1 parent 4f7360e commit 0549c65
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Showing 4 changed files with 81 additions and 52 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 263e368a2f1f960db07d7524a4a3e7df951f1f72
refs/heads/master: 235a4ce79feb8d5351f9164981bc57d5e29f974b
58 changes: 7 additions & 51 deletions trunk/arch/arm/kernel/kprobes-arm.c
Original file line number Diff line number Diff line change
Expand Up @@ -437,54 +437,6 @@ static void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs)
regs->uregs[rd] = regs->ARM_cpsr & mask;
}

static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs)
{
kprobe_opcode_t insn = p->opcode;
int rn = (insn >> 16) & 0xf;
int lbit = insn & (1 << 20);
int wbit = insn & (1 << 21);
int ubit = insn & (1 << 23);
int pbit = insn & (1 << 24);
long *addr = (long *)regs->uregs[rn];
int reg_bit_vector;
int reg_count;

reg_count = 0;
reg_bit_vector = insn & 0xffff;
while (reg_bit_vector) {
reg_bit_vector &= (reg_bit_vector - 1);
++reg_count;
}

if (!ubit)
addr -= reg_count;
addr += (!pbit == !ubit);

reg_bit_vector = insn & 0xffff;
while (reg_bit_vector) {
int reg = __ffs(reg_bit_vector);
reg_bit_vector &= (reg_bit_vector - 1);
if (lbit)
regs->uregs[reg] = *addr++;
else
*addr++ = regs->uregs[reg];
}

if (wbit) {
if (!ubit)
addr -= reg_count;
addr -= (!pbit == !ubit);
regs->uregs[rn] = (long)addr;
}
}

static void __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs)
{
regs->ARM_pc = (long)p->addr + str_pc_offset;
simulate_ldm1stm1(p, regs);
regs->ARM_pc = (long)p->addr + 4;
}

static void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs)
{
regs->uregs[12] = regs->uregs[13];
Expand Down Expand Up @@ -1463,9 +1415,13 @@ space_cccc_100x(kprobe_opcode_t insn, struct arch_specific_insn *asi)

/* LDM(1) : cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
/* STM(1) : cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */
asi->insn_handler = ((insn & 0x108000) == 0x008000) ? /* STM & R15 */
simulate_stm1_pc : simulate_ldm1stm1;
return INSN_GOOD_NO_SLOT;

/*
* Make the instruction unconditional because the new emulation
* functions don't bother to setup the PSR context.
*/
insn = (insn | 0xe0000000) & ~0x10000000;
return kprobe_decode_ldmstm(insn, asi);
}

static enum kprobe_insn __kprobes
Expand Down
70 changes: 70 additions & 0 deletions trunk/arch/arm/kernel/kprobes-common.c
Original file line number Diff line number Diff line change
Expand Up @@ -166,6 +166,76 @@ void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs)
p->ainsn.insn_fn();
}

static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs)
{
kprobe_opcode_t insn = p->opcode;
int rn = (insn >> 16) & 0xf;
int lbit = insn & (1 << 20);
int wbit = insn & (1 << 21);
int ubit = insn & (1 << 23);
int pbit = insn & (1 << 24);
long *addr = (long *)regs->uregs[rn];
int reg_bit_vector;
int reg_count;

reg_count = 0;
reg_bit_vector = insn & 0xffff;
while (reg_bit_vector) {
reg_bit_vector &= (reg_bit_vector - 1);
++reg_count;
}

if (!ubit)
addr -= reg_count;
addr += (!pbit == !ubit);

reg_bit_vector = insn & 0xffff;
while (reg_bit_vector) {
int reg = __ffs(reg_bit_vector);
reg_bit_vector &= (reg_bit_vector - 1);
if (lbit)
regs->uregs[reg] = *addr++;
else
*addr++ = regs->uregs[reg];
}

if (wbit) {
if (!ubit)
addr -= reg_count;
addr -= (!pbit == !ubit);
regs->uregs[rn] = (long)addr;
}
}

static void __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs)
{
regs->ARM_pc = (long)p->addr + str_pc_offset;
simulate_ldm1stm1(p, regs);
regs->ARM_pc = (long)p->addr + 4;
}

static void __kprobes simulate_ldm1_pc(struct kprobe *p, struct pt_regs *regs)
{
simulate_ldm1stm1(p, regs);
load_write_pc(regs->ARM_pc, regs);
}

enum kprobe_insn __kprobes
kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi)
{
kprobe_insn_handler_t *handler = 0;
unsigned reglist = insn & 0xffff;
int is_ldm = insn & 0x100000;

if (reglist & 0x8000)
handler = is_ldm ? simulate_ldm1_pc : simulate_stm1_pc;
else
handler = simulate_ldm1stm1;
asi->insn_handler = handler;
return INSN_GOOD_NO_SLOT;
}


/*
* Prepare an instruction slot to receive an instruction for emulating.
* This is done by placing a subroutine return after the location where the
Expand Down
3 changes: 3 additions & 0 deletions trunk/arch/arm/kernel/kprobes.h
Original file line number Diff line number Diff line change
Expand Up @@ -136,6 +136,9 @@ static inline void __kprobes load_write_pc(long pcv, struct pt_regs *regs)
void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs);
void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs);

enum kprobe_insn __kprobes
kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi);

/*
* Test if load/store instructions writeback the address register.
* if P (bit 24) == 0 or W (bit 21) == 1
Expand Down

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