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Diffstat (limited to 'arch/mips/kernel/unaligned.c')
-rw-r--r--arch/mips/kernel/unaligned.c94
1 files changed, 59 insertions, 35 deletions
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
index 18c4a3c45a31..d34b1fb3665d 100644
--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c
@@ -77,6 +77,7 @@
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/sched.h>
+#include <linux/debugfs.h>
#include <asm/asm.h>
#include <asm/branch.h>
#include <asm/byteorder.h>
@@ -87,20 +88,27 @@
#define STR(x) __STR(x)
#define __STR(x) #x
-#ifdef CONFIG_PROC_FS
-unsigned long unaligned_instructions;
+enum {
+ UNALIGNED_ACTION_QUIET,
+ UNALIGNED_ACTION_SIGNAL,
+ UNALIGNED_ACTION_SHOW,
+};
+#ifdef CONFIG_DEBUG_FS
+static u32 unaligned_instructions;
+static u32 unaligned_action;
+#else
+#define unaligned_action UNALIGNED_ACTION_QUIET
#endif
+extern void show_registers(struct pt_regs *regs);
-static inline int emulate_load_store_insn(struct pt_regs *regs,
- void __user *addr, unsigned int __user *pc,
- unsigned long **regptr, unsigned long *newvalue)
+static void emulate_load_store_insn(struct pt_regs *regs,
+ void __user *addr, unsigned int __user *pc)
{
union mips_instruction insn;
unsigned long value;
unsigned int res;
regs->regs[0] = 0;
- *regptr=NULL;
/*
* This load never faults.
@@ -169,8 +177,8 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
- *newvalue = value;
- *regptr = &regs->regs[insn.i_format.rt];
+ compute_return_epc(regs);
+ regs->regs[insn.i_format.rt] = value;
break;
case lw_op:
@@ -199,8 +207,8 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
- *newvalue = value;
- *regptr = &regs->regs[insn.i_format.rt];
+ compute_return_epc(regs);
+ regs->regs[insn.i_format.rt] = value;
break;
case lhu_op:
@@ -233,8 +241,8 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
- *newvalue = value;
- *regptr = &regs->regs[insn.i_format.rt];
+ compute_return_epc(regs);
+ regs->regs[insn.i_format.rt] = value;
break;
case lwu_op:
@@ -273,8 +281,8 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
- *newvalue = value;
- *regptr = &regs->regs[insn.i_format.rt];
+ compute_return_epc(regs);
+ regs->regs[insn.i_format.rt] = value;
break;
#endif /* CONFIG_64BIT */
@@ -315,8 +323,8 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
- *newvalue = value;
- *regptr = &regs->regs[insn.i_format.rt];
+ compute_return_epc(regs);
+ regs->regs[insn.i_format.rt] = value;
break;
#endif /* CONFIG_64BIT */
@@ -357,6 +365,7 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (value), "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
+ compute_return_epc(regs);
break;
case sw_op:
@@ -387,6 +396,7 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (value), "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
+ compute_return_epc(regs);
break;
case sd_op:
@@ -425,6 +435,7 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
: "r" (value), "r" (addr), "i" (-EFAULT));
if (res)
goto fault;
+ compute_return_epc(regs);
break;
#endif /* CONFIG_64BIT */
@@ -459,38 +470,35 @@ static inline int emulate_load_store_insn(struct pt_regs *regs,
goto sigill;
}
-#ifdef CONFIG_PROC_FS
+#ifdef CONFIG_DEBUG_FS
unaligned_instructions++;
#endif
- return 0;
+ return;
fault:
/* Did we have an exception handler installed? */
if (fixup_exception(regs))
- return 1;
+ return;
die_if_kernel ("Unhandled kernel unaligned access", regs);
send_sig(SIGSEGV, current, 1);
- return 0;
+ return;
sigbus:
die_if_kernel("Unhandled kernel unaligned access", regs);
send_sig(SIGBUS, current, 1);
- return 0;
+ return;
sigill:
die_if_kernel("Unhandled kernel unaligned access or invalid instruction", regs);
send_sig(SIGILL, current, 1);
-
- return 0;
}
asmlinkage void do_ade(struct pt_regs *regs)
{
- unsigned long *regptr, newval;
extern int do_dsemulret(struct pt_regs *);
unsigned int __user *pc;
mm_segment_t seg;
@@ -514,8 +522,12 @@ asmlinkage void do_ade(struct pt_regs *regs)
goto sigbus;
pc = (unsigned int __user *) exception_epc(regs);
- if (user_mode(regs) && (current->thread.mflags & MF_FIXADE) == 0)
+ if (user_mode(regs) && !test_thread_flag(TIF_FIXADE))
+ goto sigbus;
+ if (unaligned_action == UNALIGNED_ACTION_SIGNAL)
goto sigbus;
+ else if (unaligned_action == UNALIGNED_ACTION_SHOW)
+ show_registers(regs);
/*
* Do branch emulation only if we didn't forward the exception.
@@ -524,16 +536,7 @@ asmlinkage void do_ade(struct pt_regs *regs)
seg = get_fs();
if (!user_mode(regs))
set_fs(KERNEL_DS);
- if (!emulate_load_store_insn(regs, (void __user *)regs->cp0_badvaddr, pc,
- &regptr, &newval)) {
- compute_return_epc(regs);
- /*
- * Now that branch is evaluated, update the dest
- * register if necessary
- */
- if (regptr)
- *regptr = newval;
- }
+ emulate_load_store_insn(regs, (void __user *)regs->cp0_badvaddr, pc);
set_fs(seg);
return;
@@ -546,3 +549,24 @@ sigbus:
* XXX On return from the signal handler we should advance the epc
*/
}
+
+#ifdef CONFIG_DEBUG_FS
+extern struct dentry *mips_debugfs_dir;
+static int __init debugfs_unaligned(void)
+{
+ struct dentry *d;
+
+ if (!mips_debugfs_dir)
+ return -ENODEV;
+ d = debugfs_create_u32("unaligned_instructions", S_IRUGO,
+ mips_debugfs_dir, &unaligned_instructions);
+ if (IS_ERR(d))
+ return PTR_ERR(d);
+ d = debugfs_create_u32("unaligned_action", S_IRUGO | S_IWUSR,
+ mips_debugfs_dir, &unaligned_action);
+ if (IS_ERR(d))
+ return PTR_ERR(d);
+ return 0;
+}
+__initcall(debugfs_unaligned);
+#endif
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-23 12:29:36 +0000