[PATCH RFC v2 52/70] MIPS: kernel: branch: Prevent BGTZL emulation for MIPS R6
From: Markos Chandras <hidden>
Date: 2015-01-16 11:06:39
Subsystem:
mips, the rest · Maintainers:
Thomas Bogendoerfer, Linus Torvalds
MIPS R6 removed the BGTZL instruction so do not try to emulate it if the R2-to-R6 emulator is not present. Signed-off-by: Markos Chandras <redacted> --- arch/mips/kernel/branch.c | 5 +++++ arch/mips/math-emu/cp1emu.c | 3 +++ 2 files changed, 8 insertions(+)
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index bf5754ac9c14..fdc6316877c7 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c@@ -618,6 +618,11 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, case bgtz_op: case bgtzl_op: + if (NO_R6EMU && (insn.i_format.opcode == bgtzl_op)) { + /* not emulating the branch likely for R6 */ + ret = -SIGILL; + break; + } /* rt field assumed to be zero */ if ((long)regs->regs[insn.i_format.rs] > 0) { epc = epc + 4 + (insn.i_format.simmediate << 2);
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 41516e2f08c7..472acb1dc3dd 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c@@ -566,6 +566,9 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, return 1; case bgtz_op: case bgtzl_op: + if (NO_R6EMU && (insn.i_format.opcode == bgtzl_op)) + break; + if ((long)regs->regs[insn.i_format.rs] > 0) *contpc = regs->cp0_epc + dec_insn.pc_inc +
--
2.2.1