diff options
| author | Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2007-06-29 19:55:48 +0400 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2007-07-10 20:33:04 +0400 |
| commit | 6312e0ee45236b6882cd26b2ccc167b1b91646fc (patch) | |
| tree | 1c5d17522d4232e4ee40512afffb199e7c99f6ce /arch/mips/kernel/unaligned.c | |
| parent | 2db30150fe4fe309c57087c661209c9ea0b5c21b (diff) | |
| download | linux-6312e0ee45236b6882cd26b2ccc167b1b91646fc.tar.xz | |
[MIPS] Add some debugfs files to debug unaligned accesses
Currently a number of unaligned instructions is counted but not used.
Add /debug/mips/unaligned_instructions file to show the value.
And add /debug/mips/unaligned_action to control behavior upon an
unaligned access. Possible actions are:
0: silently fixup the unaligned access.
1: send SIGBUS.
2: dump registers, process name, etc. and fixup.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/unaligned.c')
| -rw-r--r-- | arch/mips/kernel/unaligned.c | 41 |
1 files changed, 38 insertions, 3 deletions
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c index 18c4a3c45a31..8b9c34ffae18 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> @@ -87,9 +88,18 @@ #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, @@ -459,7 +469,7 @@ static inline int emulate_load_store_insn(struct pt_regs *regs, goto sigill; } -#ifdef CONFIG_PROC_FS +#ifdef CONFIG_DEBUG_FS unaligned_instructions++; #endif @@ -516,6 +526,10 @@ asmlinkage void do_ade(struct pt_regs *regs) pc = (unsigned int __user *) exception_epc(regs); if (user_mode(regs) && (current->thread.mflags & MF_FIXADE) == 0) 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. @@ -546,3 +560,24 @@ 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 |