Commit 6eae3548 authored by Markos Chandras's avatar Markos Chandras Committed by Ralf Baechle
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MIPS: unaligned: Fix regular load/store instruction emulation for EVA 



When emulating a regular lh/lw/lhu/sh/sw we need to use the appropriate
instruction if we are in EVA mode. This is necessary for userspace
applications which trigger alignment exceptions. In such case, the
userspace load/store instruction needs to be emulated with the correct
eva/non-eva instruction by the kernel emulator.

Signed-off-by: default avatarMarkos Chandras <markos.chandras@imgtec.com>
Fixes: c1771216 ("MIPS: kernel: unaligned: Handle unaligned accesses for EVA")
Cc: <stable@vger.kernel.org> # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9503/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 3563c32d

arch/mips/kernel/unaligned.c

+47 −5
Original line number Diff line number Diff line
@@ -1023,7 +1023,15 @@ static void emulate_load_store_insn(struct pt_regs *regs, 
		if (!access_ok(VERIFY_READ, addr, 2))

			goto sigbus;



		if (config_enabled(CONFIG_EVA)) {

			if (segment_eq(get_fs(), get_ds()))

				LoadHW(addr, value, res);

			else

				LoadHWE(addr, value, res);

		} else {

			LoadHW(addr, value, res);

		}



		if (res)

			goto fault;

		compute_return_epc(regs);
@@ -1034,7 +1042,15 @@ static void emulate_load_store_insn(struct pt_regs *regs, 
		if (!access_ok(VERIFY_READ, addr, 4))

			goto sigbus;



		if (config_enabled(CONFIG_EVA)) {

			if (segment_eq(get_fs(), get_ds()))

				LoadW(addr, value, res);

			else

				LoadWE(addr, value, res);

		} else {

			LoadW(addr, value, res);

		}



		if (res)

			goto fault;

		compute_return_epc(regs);
@@ -1045,7 +1061,15 @@ static void emulate_load_store_insn(struct pt_regs *regs, 
		if (!access_ok(VERIFY_READ, addr, 2))

			goto sigbus;



		if (config_enabled(CONFIG_EVA)) {

			if (segment_eq(get_fs(), get_ds()))

				LoadHWU(addr, value, res);

			else

				LoadHWUE(addr, value, res);

		} else {

			LoadHWU(addr, value, res);

		}



		if (res)

			goto fault;

		compute_return_epc(regs);
@@ -1104,7 +1128,16 @@ static void emulate_load_store_insn(struct pt_regs *regs, 


		compute_return_epc(regs);

		value = regs->regs[insn.i_format.rt];



		if (config_enabled(CONFIG_EVA)) {

			if (segment_eq(get_fs(), get_ds()))

				StoreHW(addr, value, res);

			else

				StoreHWE(addr, value, res);

		} else {

			StoreHW(addr, value, res);

		}



		if (res)

			goto fault;

		break;
@@ -1115,7 +1148,16 @@ static void emulate_load_store_insn(struct pt_regs *regs, 


		compute_return_epc(regs);

		value = regs->regs[insn.i_format.rt];



		if (config_enabled(CONFIG_EVA)) {

			if (segment_eq(get_fs(), get_ds()))

				StoreW(addr, value, res);

			else

				StoreWE(addr, value, res);

		} else {

			StoreW(addr, value, res);

		}



		if (res)

			goto fault;

		break;

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