From ca86c9ef2b322ebf24772009fdea037688cbdac1 Mon Sep 17 00:00:00 2001 From: Marcin Nowakowski Date: Thu, 22 Sep 2016 15:38:33 +0200 Subject: [PATCH] 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 Fixes: 40e084a506eb ('MIPS: Add uprobes support.') Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14300/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/uprobes.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/mips/kernel/uprobes.c b/arch/mips/kernel/uprobes.c index 3b8accb0b4f0..4c7c1558944a 100644 --- a/arch/mips/kernel/uprobes.c +++ b/arch/mips/kernel/uprobes.c @@ -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;