[PATCH v2 4/4] MIPS: unaligned: Fix regular load/store instruction emulation for EVA
From: Markos Chandras <hidden>
Date: 2015-03-09 14:56:45
Subsystem:
mips, the rest · Maintainers:
Thomas Bogendoerfer, Linus Torvalds
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.
Fixes: c1771216ab48 ("MIPS: kernel: unaligned: Handle unaligned accesses for EVA")
Cc: <redacted> # v3.15+
Signed-off-by: Markos Chandras <redacted>
---
arch/mips/kernel/unaligned.c | 52 +++++++++++++++++++++++++++++++++++++++-----
1 file changed, 47 insertions(+), 5 deletions(-)
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
index ab475903175f..7659da224fcd 100644
--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c@@ -1023,7 +1023,15 @@ static void emulate_load_store_insn(struct pt_regs *regs, 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(struct pt_regs *regs, 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(struct pt_regs *regs, 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(struct pt_regs *regs, 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(struct pt_regs *regs, 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;
--
2.3.1