Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f6a31da5 authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Ralf Baechle
Browse files

MIPS: BREAK instruction interpretation corrections 



Add the missing microMIPS BREAK16 instruction code interpretation and
reshape code removing instruction fetching duplication and the separate
call to `do_trap_or_bp' in the MIPS16 path.

Signed-off-by: default avatarMaciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9696/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 68893e00

arch/mips/kernel/traps.c

+18 −18
Original line number Diff line number Diff line
@@ -901,10 +901,9 @@ void do_trap_or_bp(struct pt_regs *regs, unsigned int code, 


asmlinkage void do_bp(struct pt_regs *regs)

{

	unsigned long epc = msk_isa16_mode(exception_epc(regs));

	unsigned int opcode, bcode;

	enum ctx_state prev_state;

	unsigned long epc;

	u16 instr[2];

	mm_segment_t seg;



	seg = get_fs();
@@ -913,26 +912,28 @@ asmlinkage void do_bp(struct pt_regs *regs) 


	prev_state = exception_enter();

	if (get_isa16_mode(regs->cp0_epc)) {

		/* Calculate EPC. */

		epc = exception_epc(regs);

		if (cpu_has_mmips) {

			if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||

			    (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))

		u16 instr[2];



		if (__get_user(instr[0], (u16 __user *)epc))

			goto out_sigsegv;

			opcode = (instr[0] << 16) | instr[1];

		} else {



		if (!cpu_has_mmips) {

			/* MIPS16e mode */

			if (__get_user(instr[0],

				       (u16 __user *)msk_isa16_mode(epc)))

				goto out_sigsegv;

			bcode = (instr[0] >> 5) & 0x3f;

			do_trap_or_bp(regs, bcode, "Break");

			goto out;

		} else if (mm_insn_16bit(instr[0])) {

			/* 16-bit microMIPS BREAK */

			bcode = instr[0] & 0xf;

		} else {

			/* 32-bit microMIPS BREAK */

			if (__get_user(instr[1], (u16 __user *)(epc + 2)))

				goto out_sigsegv;

			opcode = (instr[0] << 16) | instr[1];

			bcode = (opcode >> 6) & ((1 << 20) - 1);

		}

	} else {

		if (__get_user(opcode,

			       (unsigned int __user *) exception_epc(regs)))

		if (__get_user(opcode, (unsigned int __user *)epc))

			goto out_sigsegv;

		bcode = (opcode >> 6) & ((1 << 20) - 1);

	}



	/*
@@ -941,7 +942,6 @@ asmlinkage void do_bp(struct pt_regs *regs) 
	 * Gas is bug-compatible, but not always, grrr...

	 * We handle both cases with a simple heuristics.  --macro

	 */

	bcode = ((opcode >> 6) & ((1 << 20) - 1));

	if (bcode >= (1 << 10))

		bcode >>= 10;