From 3d50a7fb42992545e45e10b068406546ea699489 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Sat, 30 Jan 2016 09:08:43 +0000 Subject: [PATCH] MIPS: traps.c: Verify the ISA for microMIPS RDHWR emulation Make sure it's the microMIPS rather than MIPS16 ISA before emulating microMIPS RDHWR. Mostly needed as an optimisation for configurations where `cpu_has_mmips' is hardcoded to 0 and also a good measure in case we add further microMIPS instructions to emulate in the future, as the corresponding MIPS16 encoding is ADDIUSP, not supposed to trap. Signed-off-by: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12282/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/traps.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 80339ce..ae0c89d 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1122,19 +1122,7 @@ no_r2_instr: if (unlikely(compute_return_epc(regs) < 0)) goto out; - if (get_isa16_mode(regs->cp0_epc)) { - unsigned short mmop[2] = { 0 }; - - if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0)) - status = SIGSEGV; - if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0)) - status = SIGSEGV; - opcode = mmop[0]; - opcode = (opcode << 16) | mmop[1]; - - if (status < 0) - status = simulate_rdhwr_mm(regs, opcode); - } else { + if (!get_isa16_mode(regs->cp0_epc)) { if (unlikely(get_user(opcode, epc) < 0)) status = SIGSEGV; @@ -1149,6 +1137,18 @@ no_r2_instr: if (status < 0) status = simulate_fp(regs, opcode, old_epc, old31); + } else if (cpu_has_mmips) { + unsigned short mmop[2] = { 0 }; + + if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0)) + status = SIGSEGV; + if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0)) + status = SIGSEGV; + opcode = mmop[0]; + opcode = (opcode << 16) | mmop[1]; + + if (status < 0) + status = simulate_rdhwr_mm(regs, opcode); } if (status < 0) -- 2.7.4