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| author | Viktor Rosendahl <viktor.rosendahl@nokia.com> | 2011-03-28 18:56:05 +0300 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-04-28 23:40:54 -0400 |
| commit | cf3cc1aa9b6d0bf1750143af65829f4368d77492 (patch) | |
| tree | cc9027ad2b4a7c7d77afa28049ebf7f97abb14d7 /arch/arm | |
| parent | 6221f222c0ebf1acdf7abcf927178f40e1a65e2a (diff) | |
| download | linux-cf3cc1aa9b6d0bf1750143af65829f4368d77492.tar.bz2 | |
kprobes/arm: Fix ldrd/strd emulation
Currently emulate_ldrd and emulate_strd don't even have the adjustment
of the PC value, so in case of Rn == PC, it will not update the PC
incorrectly but instead load/store from the wrong address. Let's add
both the adjustment of the PC value and the check for PC == PC.
Signed-off-by: Viktor Rosendahl <viktor.rosendahl@nokia.com>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kernel/kprobes-decode.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index 23891317dc4b..3b0cf90cb449 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -540,9 +540,12 @@ static void __kprobes emulate_ldrd(struct kprobe *p, struct pt_regs *regs) { insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; int rd = (insn >> 12) & 0xf; int rn = (insn >> 16) & 0xf; int rm = insn & 0xf; /* rm may be invalid, don't care. */ + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; /* Not following the C calling convention here, so need asm(). */ __asm__ __volatile__ ( @@ -554,29 +557,36 @@ static void __kprobes emulate_ldrd(struct kprobe *p, struct pt_regs *regs) "str r0, %[rn] \n\t" /* in case of writeback */ "str r2, %[rd0] \n\t" "str r3, %[rd1] \n\t" - : [rn] "+m" (regs->uregs[rn]), + : [rn] "+m" (rnv), [rd0] "=m" (regs->uregs[rd]), [rd1] "=m" (regs->uregs[rd+1]) - : [rm] "m" (regs->uregs[rm]), + : [rm] "m" (rmv), [cpsr] "r" (regs->ARM_cpsr), [i_fn] "r" (i_fn) : "r0", "r1", "r2", "r3", "lr", "cc" ); + if (rn != 15) + regs->uregs[rn] = rnv; /* Save Rn in case of writeback. */ } static void __kprobes emulate_strd(struct kprobe *p, struct pt_regs *regs) { insn_4arg_fn_t *i_fn = (insn_4arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; + long ppc = (long)p->addr + 8; int rd = (insn >> 12) & 0xf; int rn = (insn >> 16) & 0xf; int rm = insn & 0xf; - long rnv = regs->uregs[rn]; - long rmv = regs->uregs[rm]; /* rm/rmv may be invalid, don't care. */ + long rnv = (rn == 15) ? ppc : regs->uregs[rn]; + /* rm/rmv may be invalid, don't care. */ + long rmv = (rm == 15) ? ppc : regs->uregs[rm]; + long rnv_wb; - regs->uregs[rn] = insnslot_4arg_rflags(rnv, rmv, regs->uregs[rd], + rnv_wb = insnslot_4arg_rflags(rnv, rmv, regs->uregs[rd], regs->uregs[rd+1], regs->ARM_cpsr, i_fn); + if (rn != 15) + regs->uregs[rn] = rnv_wb; /* Save Rn in case of writeback. */ } static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs) |