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authorMaciej W. Rozycki <macro@imgtec.com>2016-01-30 09:08:28 +0000
committerRalf Baechle <ralf@linux-mips.org>2016-02-02 02:16:29 +0100
commit7aa7047100113ec9f5e4e685f94223825bd74a7b (patch)
tree6bea043bb48433dd7867fba6856ca0611ca24c7a /arch
parentMIPS: traps.c: Don't emulate RDHWR in the CpU #0 exception handler (diff)
downloadlinux-dev-7aa7047100113ec9f5e4e685f94223825bd74a7b.tar.xz
linux-dev-7aa7047100113ec9f5e4e685f94223825bd74a7b.zip
MIPS: traps.c: Correct microMIPS RDHWR emulation
Fix the code to fetch and decode the whole 32-bit instruction. This only really matters with the `noulri' kernel parameter as all microMIPS processors are supposed to have all the hardware registers we support. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12281/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/traps.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 485b0d517177..ae790c575d4f 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -663,7 +663,7 @@ static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
return -1;
}
-static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
+static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
{
if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
int rd = (opcode & MM_RS) >> 16;
@@ -1119,11 +1119,12 @@ no_r2_instr:
if (get_isa16_mode(regs->cp0_epc)) {
unsigned short mmop[2] = { 0 };
- if (unlikely(get_user(mmop[0], epc) < 0))
+ if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
status = SIGSEGV;
- if (unlikely(get_user(mmop[1], epc) < 0))
+ if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
status = SIGSEGV;
- opcode = (mmop[0] << 16) | mmop[1];
+ opcode = mmop[0];
+ opcode = (opcode << 16) | mmop[1];
if (status < 0)
status = simulate_rdhwr_mm(regs, opcode);