MIPS: uprobes: fix use of uninitialised variable

arch_uprobe_pre_xol needs to emulate a branch if a branch instruction
has been replaced with a breakpoint, but in fact an uninitialised local
variable was passed to the emulator routine instead of the original
instruction

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a506 ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14300/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Marcin Nowakowski 2016-09-22 15:38:33 +02:00 committed by Ralf Baechle
parent ddabfa5c2e
commit ca86c9ef2b
1 changed files with 2 additions and 3 deletions

View File

@ -157,7 +157,6 @@ bool is_trap_insn(uprobe_opcode_t *insn)
int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs)
{
struct uprobe_task *utask = current->utask;
union mips_instruction insn;
/*
* Now find the EPC where to resume after the breakpoint has been
@ -168,10 +167,10 @@ int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs)
unsigned long epc;
epc = regs->cp0_epc;
__compute_return_epc_for_insn(regs, insn);
__compute_return_epc_for_insn(regs,
(union mips_instruction) aup->insn[0]);
aup->resume_epc = regs->cp0_epc;
}
utask->autask.saved_trap_nr = current->thread.trap_nr;
current->thread.trap_nr = UPROBE_TRAP_NR;
regs->cp0_epc = current->utask->xol_vaddr;