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Commit ca86c9ef authored by Marcin Nowakowski's avatar Marcin Nowakowski Committed by Ralf Baechle
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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: default avatarMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Fixes: 40e084a5 ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14300/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent ddabfa5c

arch/mips/kernel/uprobes.c

+2 −3
Original line number Diff line number Diff line
@@ -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;