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authorMarcin Nowakowski <marcin.nowakowski@imgtec.com>2016-09-22 15:38:33 +0200
committerRalf Baechle <ralf@linux-mips.org>2016-09-29 18:59:49 +0200
commitca86c9ef2b322ebf24772009fdea037688cbdac1 (patch)
tree4e75f9772e002ae39af5fd62745137961f8c1443
parentddabfa5c2e33f1b495f3e0176de7057850915c0b (diff)
downloadlinux-0-day-ca86c9ef2b322ebf24772009fdea037688cbdac1.tar.gz
linux-0-day-ca86c9ef2b322ebf24772009fdea037688cbdac1.tar.xz
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: 40e084a506eb ('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>
-rw-r--r--arch/mips/kernel/uprobes.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/mips/kernel/uprobes.c b/arch/mips/kernel/uprobes.c
index 3b8accb0b4f01..4c7c1558944a2 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;