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Commit 3d50a7fb authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Ralf Baechle
Browse files

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: default avatarMaciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12282/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 6870e707

arch/mips/kernel/traps.c

+13 −13
Original line number Diff line number Diff line
@@ -1122,19 +1122,7 @@ asmlinkage void do_ri(struct pt_regs *regs) 
	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 @@ asmlinkage void do_ri(struct pt_regs *regs) 


		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)