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| author | Paul Mundt <lethal@linux-sh.org> | 2006-12-08 09:41:43 +0100 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2006-12-12 00:42:08 +0100 |
| commit | dc34d312c7b25d5d0f54c16d143a9526936e5d38 (patch) | |
| tree | 3f409a98a130e688ffbe7787f18166b2a29f08a4 /arch | |
| parent | rtc: rtc-sh: alarm support. (diff) | |
| download | linux-dc34d312c7b25d5d0f54c16d143a9526936e5d38.tar.xz linux-dc34d312c7b25d5d0f54c16d143a9526936e5d38.zip | |
sh: BUG() handling through trapa vector.
Previously we haven't been doing anything with verbose BUG() reporting,
and we've been relying on the oops path for handling BUG()'s, which is
rather sub-optimal.
This switches BUG handling to use a fixed trapa vector (#0x3e) where we
construct a small bug frame post trapa instruction to get the context
right. This also makes it trivial to wire up a DIE_BUG for the atomic
die chain, which we couldn't really do before.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/sh/kernel/process.c | 10 | ||||
| -rw-r--r-- | arch/sh/kernel/traps.c | 35 |
2 files changed, 45 insertions, 0 deletions
diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c index f3e2631be144..7347f6afa030 100644 --- a/arch/sh/kernel/process.c +++ b/arch/sh/kernel/process.c @@ -498,6 +498,16 @@ asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5, { struct pt_regs *regs = RELOC_HIDE(&__regs, 0); + /* Rewind */ regs->pc -= 2; + +#ifdef CONFIG_BUG + if (__kernel_text_address(instruction_pointer(regs))) { + u16 insn = *(u16 *)instruction_pointer(regs); + if (insn == TRAPA_BUG_OPCODE) + handle_BUG(regs); + } +#endif + force_sig(SIGTRAP, current); } diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c index 3762d9dc2046..ec110157992d 100644 --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -19,6 +19,7 @@ #include <linux/kallsyms.h> #include <linux/io.h> #include <linux/debug_locks.h> +#include <linux/limits.h> #include <asm/system.h> #include <asm/uaccess.h> @@ -129,6 +130,40 @@ static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err) return -EFAULT; } +#ifdef CONFIG_BUG +#ifdef CONFIG_DEBUG_BUGVERBOSE +static inline void do_bug_verbose(struct pt_regs *regs) +{ + struct bug_frame f; + long len; + + if (__copy_from_user(&f, (const void __user *)regs->pc, + sizeof(struct bug_frame))) + return; + + len = __strnlen_user(f.file, PATH_MAX) - 1; + if (unlikely(len < 0 || len >= PATH_MAX)) + f.file = "<bad filename>"; + len = __strnlen_user(f.func, PATH_MAX) - 1; + if (unlikely(len < 0 || len >= PATH_MAX)) + f.func = "<bad function>"; + + printk(KERN_ALERT "kernel BUG in %s() at %s:%d!\n", + f.func, f.file, f.line); +} +#else +static inline void do_bug_verbose(struct pt_regs *regs) +{ +} +#endif /* CONFIG_DEBUG_BUGVERBOSE */ +#endif /* CONFIG_BUG */ + +void handle_BUG(struct pt_regs *regs) +{ + do_bug_verbose(regs); + die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); +} + /* * handle an instruction that does an unaligned memory access by emulating the * desired behaviour |