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Patch "MIPS: unaligned: Fix regular load/store instruction emulation for EVA" has been added to the 4.0-stable tree

PATCH [email protected] 1 participant 1 message May 2, 2015

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This is a note to let you know that I've just added the patch titled

MIPS: unaligned: Fix regular load/store instruction emulation for EVA

to the 4.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mips-unaligned-fix-regular-load-store-instruction-emulation-for-eva.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 6eae35485b26f9e51ab896eb8a936bed9908fdf6 Mon Sep 17 00:00:00 2001

From: Markos Chandras <[email protected]>
Date: Mon, 9 Mar 2015 14:54:52 +0000
Subject: MIPS: unaligned: Fix regular load/store instruction emulation for EVA

From: Markos Chandras <[email protected]>

commit 6eae35485b26f9e51ab896eb8a936bed9908fdf6 upstream.

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 Markos Chandras <[email protected]>
Fixes c1771216ab48 ("MIPS: kernel: unaligned: Handle unaligned accesses for EVA")
Cc [email protected]

Patchwork: https://patchwork.linux-mips.org/patch/9503/

Signed-off-by Ralf Baechle <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 arch/mips/kernel/unaligned.c |   52 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 5 deletions(-)
arch/mips/kernel/unaligned.c +47 -5
@@ -1023,7 +1023,15 @@ static void emulate_load_store_insn(stru
 		if (!access_ok(VERIFY_READ, addr, 2))
 			goto sigbus;
 
-		LoadHW(addr, value, res);
+		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(stru
 		if (!access_ok(VERIFY_READ, addr, 4))
 			goto sigbus;
 
-		LoadW(addr, value, res);
+		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(stru
 		if (!access_ok(VERIFY_READ, addr, 2))
 			goto sigbus;
 
-		LoadHWU(addr, value, res);
+		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(stru
 
 		compute_return_epc(regs);
 		value = regs->regs[insn.i_format.rt];
-		StoreHW(addr, value, res);
+
+		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(stru
 
 		compute_return_epc(regs);
 		value = regs->regs[insn.i_format.rt];
-		StoreW(addr, value, res);
+
+		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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.0/mips-unaligned-fix-regular-load-store-instruction-emulation-for-eva.patch queue-4.0/mips-unaligned-prevent-eva-instructions-on-kernel-unaligned-accesses.patch queue-4.0/mips-malta-detect-and-fix-bad-memsize-values.patch queue-4.0/mips-unaligned-surround-load-store-macros-in-do-while-statements.patch queue-4.0/mips-asm-asm-eva-introduce-kernel-load-store-variants.patch