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authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>2007-06-30 00:55:48 +0900
committerRalf Baechle <ralf@linux-mips.org>2007-07-10 17:33:04 +0100
commit6312e0ee45236b6882cd26b2ccc167b1b91646fc (patch)
tree1c5d17522d4232e4ee40512afffb199e7c99f6ce /arch
parent2db30150fe4fe309c57087c661209c9ea0b5c21b (diff)
downloadlinux-2.6.34-ux500-6312e0ee45236b6882cd26b2ccc167b1b91646fc.tar.gz
[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')
-rw-r--r--arch/mips/kernel/setup.c16
-rw-r--r--arch/mips/kernel/unaligned.c41
2 files changed, 54 insertions, 3 deletions
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 4975da0bfb6..316685fca05 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -20,6 +20,7 @@
#include <linux/highmem.h>
#include <linux/console.h>
#include <linux/pfn.h>
+#include <linux/debugfs.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
@@ -574,3 +575,18 @@ __setup("nodsp", dsp_disable);
unsigned long kernelsp[NR_CPUS];
unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
+
+#ifdef CONFIG_DEBUG_FS
+struct dentry *mips_debugfs_dir;
+static int __init debugfs_mips(void)
+{
+ struct dentry *d;
+
+ d = debugfs_create_dir("mips", NULL);
+ if (IS_ERR(d))
+ return PTR_ERR(d);
+ mips_debugfs_dir = d;
+ return 0;
+}
+arch_initcall(debugfs_mips);
+#endif
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
index 18c4a3c45a3..8b9c34ffae1 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