diff options
Diffstat (limited to 'arch/tile/kernel/traps.c')
| -rw-r--r-- | arch/tile/kernel/traps.c | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c index a1bbc5de4d00..cfff6f958d58 100644 --- a/arch/tile/kernel/traps.c +++ b/arch/tile/kernel/traps.c @@ -15,6 +15,7 @@ #include <linux/sched.h> #include <linux/kernel.h> #include <linux/kprobes.h> +#include <linux/kdebug.h> #include <linux/module.h> #include <linux/reboot.h> #include <linux/uaccess.h> @@ -214,6 +215,43 @@ static const char *const int_name[] = { #endif }; +static int do_bpt(struct pt_regs *regs) +{ + unsigned long bundle, bcode, bpt; + + bundle = *(unsigned long *)instruction_pointer(regs); + + /* + * bpt shoule be { bpt; nop }, which is 0x286a44ae51485000ULL. + * we encode the unused least significant bits for other purpose. + */ + bpt = bundle & ~((1ULL << 12) - 1); + if (bpt != TILE_BPT_BUNDLE) + return 0; + + bcode = bundle & ((1ULL << 12) - 1); + /* + * notify the kprobe handlers, if instruction is likely to + * pertain to them. + */ + switch (bcode) { + /* breakpoint_insn */ + case 0: + notify_die(DIE_BREAK, "debug", regs, bundle, + INT_ILL, SIGTRAP); + break; + /* breakpoint2_insn */ + case DIE_SSTEPBP: + notify_die(DIE_SSTEPBP, "single_step", regs, bundle, + INT_ILL, SIGTRAP); + break; + default: + return 0; + } + + return 1; +} + void __kprobes do_trap(struct pt_regs *regs, int fault_num, unsigned long reason) { @@ -221,6 +259,11 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, int signo, code; unsigned long address = 0; bundle_bits instr; + int is_kernel = !user_mode(regs); + + /* Handle breakpoints, etc. */ + if (is_kernel && fault_num == INT_ILL && do_bpt(regs)) + return; /* Re-enable interrupts, if they were previously enabled. */ if (!(regs->flags & PT_FLAGS_DISABLE_IRQ)) @@ -230,7 +273,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, * If it hits in kernel mode and we can't fix it up, just exit the * current process and hope for the best. */ - if (!user_mode(regs)) { + if (is_kernel) { const char *name; char buf[100]; if (fixup_exception(regs)) /* ILL_TRANS or UNALIGN_DATA */ |