redonkable/alistair23-linux
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MIPS: Fix branch emulation of branch likely instructions.

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Two issues:

  o For beql_op, beql_op, bne_op, bnel_op, blez_op, blezl_op, bgtz_op and
    bgtzl_op the wrong field was being checked for the instruction opcode.
  o For blez_op / blezl_op and bgtz_op / bgtzl_op the test was testing
    for the wrong opcode.

This bug got introduced by d8d4e3ae0b [MIPS
Kprobes: Refactor branch emulation].

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Acked-by: Victor Kamensky <kamensky@cisco.com>
This commit is contained in:
Ralf Baechle 2014-05-22 23:19:00 +02:00
parent dc93f7b68a
commit 41ca86e850
1 changed files with 4 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
arch/mips/kernel/branch.c
View file

@ -317,7 +317,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
if (regs->regs[insn.i_format.rs] ==
regs->regs[insn.i_format.rt]) {
epc = epc + 4 + (insn.i_format.simmediate << 2);
if (insn.i_format.rt == beql_op)
if (insn.i_format.opcode == beql_op)
ret = BRANCH_LIKELY_TAKEN;
} else
epc += 8;
@ -329,7 +329,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
if (regs->regs[insn.i_format.rs] !=
regs->regs[insn.i_format.rt]) {
epc = epc + 4 + (insn.i_format.simmediate << 2);
if (insn.i_format.rt == bnel_op)
if (insn.i_format.opcode == bnel_op)
ret = BRANCH_LIKELY_TAKEN;
} else
epc += 8;
@ -341,7 +341,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
/* rt field assumed to be zero */
if ((long)regs->regs[insn.i_format.rs] <= 0) {
epc = epc + 4 + (insn.i_format.simmediate << 2);
if (insn.i_format.rt == bnel_op)
if (insn.i_format.opcode == blezl_op)
ret = BRANCH_LIKELY_TAKEN;
} else
epc += 8;
@ -353,7 +353,7 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
/* rt field assumed to be zero */
if ((long)regs->regs[insn.i_format.rs] > 0) {
epc = epc + 4 + (insn.i_format.simmediate << 2);
if (insn.i_format.rt == bnel_op)
if (insn.i_format.opcode == bgtzl_op)
ret = BRANCH_LIKELY_TAKEN;
} else
epc += 8;