summaryrefslogtreecommitdiff
path: root/arch/mips/kernel/traps.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/kernel/traps.c')
-rw-r--r--arch/mips/kernel/traps.c164
1 files changed, 86 insertions, 78 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 9c0c478..bbf01b8 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -9,9 +9,10 @@
* Copyright (C) 1999 Silicon Graphics, Inc.
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000, 01 MIPS Technologies, Inc.
- * Copyright (C) 2002, 2003, 2004, 2005 Maciej W. Rozycki
+ * Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
*/
#include <linux/bug.h>
+#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
@@ -410,7 +411,7 @@ asmlinkage void do_be(struct pt_regs *regs)
}
/*
- * ll/sc emulation
+ * ll/sc, rdhwr, sync emulation
*/
#define OPCODE 0xfc000000
@@ -419,9 +420,11 @@ asmlinkage void do_be(struct pt_regs *regs)
#define OFFSET 0x0000ffff
#define LL 0xc0000000
#define SC 0xe0000000
+#define SPEC0 0x00000000
#define SPEC3 0x7c000000
#define RD 0x0000f800
#define FUNC 0x0000003f
+#define SYNC 0x0000000f
#define RDHWR 0x0000003b
/*
@@ -432,11 +435,10 @@ unsigned long ll_bit;
static struct task_struct *ll_task = NULL;
-static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
+static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
{
unsigned long value, __user *vaddr;
long offset;
- int signal = 0;
/*
* analyse the ll instruction that just caused a ri exception
@@ -451,14 +453,10 @@ static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
vaddr = (unsigned long __user *)
((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
- if ((unsigned long)vaddr & 3) {
- signal = SIGBUS;
- goto sig;
- }
- if (get_user(value, vaddr)) {
- signal = SIGSEGV;
- goto sig;
- }
+ if ((unsigned long)vaddr & 3)
+ return SIGBUS;
+ if (get_user(value, vaddr))
+ return SIGSEGV;
preempt_disable();
@@ -471,22 +469,16 @@ static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
preempt_enable();
- compute_return_epc(regs);
-
regs->regs[(opcode & RT) >> 16] = value;
- return;
-
-sig:
- force_sig(signal, current);
+ return 0;
}
-static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
+static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
{
unsigned long __user *vaddr;
unsigned long reg;
long offset;
- int signal = 0;
/*
* analyse the sc instruction that just caused a ri exception
@@ -502,34 +494,25 @@ static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
reg = (opcode & RT) >> 16;
- if ((unsigned long)vaddr & 3) {
- signal = SIGBUS;
- goto sig;
- }
+ if ((unsigned long)vaddr & 3)
+ return SIGBUS;
preempt_disable();
if (ll_bit == 0 || ll_task != current) {
- compute_return_epc(regs);
regs->regs[reg] = 0;
preempt_enable();
- return;
+ return 0;
}
preempt_enable();
- if (put_user(regs->regs[reg], vaddr)) {
- signal = SIGSEGV;
- goto sig;
- }
+ if (put_user(regs->regs[reg], vaddr))
+ return SIGSEGV;
- compute_return_epc(regs);
regs->regs[reg] = 1;
- return;
-
-sig:
- force_sig(signal, current);
+ return 0;
}
/*
@@ -539,27 +522,14 @@ sig:
* few processors such as NEC's VR4100 throw reserved instruction exceptions
* instead, so we're doing the emulation thing in both exception handlers.
*/
-static inline int simulate_llsc(struct pt_regs *regs)
+static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
{
- unsigned int opcode;
-
- if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
- goto out_sigsegv;
-
- if ((opcode & OPCODE) == LL) {
- simulate_ll(regs, opcode);
- return 0;
- }
- if ((opcode & OPCODE) == SC) {
- simulate_sc(regs, opcode);
- return 0;
- }
-
- return -EFAULT; /* Strange things going on ... */
+ if ((opcode & OPCODE) == LL)
+ return simulate_ll(regs, opcode);
+ if ((opcode & OPCODE) == SC)
+ return simulate_sc(regs, opcode);
-out_sigsegv:
- force_sig(SIGSEGV, current);
- return -EFAULT;
+ return -1; /* Must be something else ... */
}
/*
@@ -567,16 +537,9 @@ out_sigsegv:
* registers not implemented in hardware. The only current use of this
* is the thread area pointer.
*/
-static inline int simulate_rdhwr(struct pt_regs *regs)
+static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
{
struct thread_info *ti = task_thread_info(current);
- unsigned int opcode;
-
- if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
- goto out_sigsegv;
-
- if (unlikely(compute_return_epc(regs)))
- return -EFAULT;
if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
int rd = (opcode & RD) >> 11;
@@ -586,16 +549,20 @@ static inline int simulate_rdhwr(struct pt_regs *regs)
regs->regs[rt] = ti->tp_value;
return 0;
default:
- return -EFAULT;
+ return -1;
}
}
/* Not ours. */
- return -EFAULT;
+ return -1;
+}
-out_sigsegv:
- force_sig(SIGSEGV, current);
- return -EFAULT;
+static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
+{
+ if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC)
+ return 0;
+
+ return -1; /* Must be something else ... */
}
asmlinkage void do_ov(struct pt_regs *regs)
@@ -767,16 +734,35 @@ out_sigsegv:
asmlinkage void do_ri(struct pt_regs *regs)
{
- die_if_kernel("Reserved instruction in kernel code", regs);
+ unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
+ unsigned long old_epc = regs->cp0_epc;
+ unsigned int opcode = 0;
+ int status = -1;
- if (!cpu_has_llsc)
- if (!simulate_llsc(regs))
- return;
+ die_if_kernel("Reserved instruction in kernel code", regs);
- if (!simulate_rdhwr(regs))
+ if (unlikely(compute_return_epc(regs) < 0))
return;
- force_sig(SIGILL, current);
+ if (unlikely(get_user(opcode, epc) < 0))
+ status = SIGSEGV;
+
+ if (!cpu_has_llsc && status < 0)
+ status = simulate_llsc(regs, opcode);
+
+ if (status < 0)
+ status = simulate_rdhwr(regs, opcode);
+
+ if (status < 0)
+ status = simulate_sync(regs, opcode);
+
+ if (status < 0)
+ status = SIGILL;
+
+ if (unlikely(status > 0)) {
+ regs->cp0_epc = old_epc; /* Undo skip-over. */
+ force_sig(status, current);
+ }
}
/*
@@ -808,7 +794,11 @@ static void mt_ase_fp_affinity(void)
asmlinkage void do_cpu(struct pt_regs *regs)
{
+ unsigned int __user *epc;
+ unsigned long old_epc;
+ unsigned int opcode;
unsigned int cpid;
+ int status;
die_if_kernel("do_cpu invoked from kernel context!", regs);
@@ -816,14 +806,32 @@ asmlinkage void do_cpu(struct pt_regs *regs)
switch (cpid) {
case 0:
- if (!cpu_has_llsc)
- if (!simulate_llsc(regs))
- return;
+ epc = (unsigned int __user *)exception_epc(regs);
+ old_epc = regs->cp0_epc;
+ opcode = 0;
+ status = -1;
- if (!simulate_rdhwr(regs))
+ if (unlikely(compute_return_epc(regs) < 0))
return;
- break;
+ if (unlikely(get_user(opcode, epc) < 0))
+ status = SIGSEGV;
+
+ if (!cpu_has_llsc && status < 0)
+ status = simulate_llsc(regs, opcode);
+
+ if (status < 0)
+ status = simulate_rdhwr(regs, opcode);
+
+ if (status < 0)
+ status = SIGILL;
+
+ if (unlikely(status > 0)) {
+ regs->cp0_epc = old_epc; /* Undo skip-over. */
+ force_sig(status, current);
+ }
+
+ return;
case 1:
if (used_math()) /* Using the FPU again. */
generated by cgit v0.10.2 at 2024-11-11 04:11:40 (GMT)