From 86f2552bbd0e17b19bb5e9881042533eaea553c7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 17 May 2010 10:00:05 +0200 Subject: [S390] add breaking event address for user space Copy the last breaking event address from the lowcore to a new field in the thread_struct on each system entry. Add a new ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset REGSET_LAST_BREAK to query the last breaking event. This is useful for debugging wild branches in user space code. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/ptrace.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) (limited to 'arch/s390/kernel/ptrace.c') diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 9f654da4cecc..83339d33c4b1 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -57,6 +57,7 @@ enum s390_regset { REGSET_GENERAL, REGSET_FP, + REGSET_LAST_BREAK, REGSET_GENERAL_EXTENDED, }; @@ -381,6 +382,10 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) copied += sizeof(unsigned long); } return 0; + case PTRACE_GET_LAST_BREAK: + put_user(task_thread_info(child)->last_break, + (unsigned long __user *) data); + return 0; default: /* Removing high order bit from addr (only for 31 bit). */ addr &= PSW_ADDR_INSN; @@ -633,6 +638,10 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, copied += sizeof(unsigned int); } return 0; + case PTRACE_GET_LAST_BREAK: + put_user(task_thread_info(child)->last_break, + (unsigned int __user *) data); + return 0; } return compat_ptrace_request(child, request, addr, data); } @@ -797,6 +806,28 @@ static int s390_fpregs_set(struct task_struct *target, return rc; } +#ifdef CONFIG_64BIT + +static int s390_last_break_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + if (count > 0) { + if (kbuf) { + unsigned long *k = kbuf; + *k = task_thread_info(target)->last_break; + } else { + unsigned long __user *u = ubuf; + if (__put_user(task_thread_info(target)->last_break, u)) + return -EFAULT; + } + } + return 0; +} + +#endif + static const struct user_regset s390_regsets[] = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, @@ -814,6 +845,15 @@ static const struct user_regset s390_regsets[] = { .get = s390_fpregs_get, .set = s390_fpregs_set, }, +#ifdef CONFIG_64BIT + [REGSET_LAST_BREAK] = { + .core_note_type = NT_S390_LAST_BREAK, + .n = 1, + .size = sizeof(long), + .align = sizeof(long), + .get = s390_last_break_get, + }, +#endif }; static const struct user_regset_view user_s390_view = { @@ -948,6 +988,27 @@ static int s390_compat_regs_high_set(struct task_struct *target, return rc; } +static int s390_compat_last_break_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + compat_ulong_t last_break; + + if (count > 0) { + last_break = task_thread_info(target)->last_break; + if (kbuf) { + unsigned long *k = kbuf; + *k = last_break; + } else { + unsigned long __user *u = ubuf; + if (__put_user(last_break, u)) + return -EFAULT; + } + } + return 0; +} + static const struct user_regset s390_compat_regsets[] = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, @@ -965,6 +1026,13 @@ static const struct user_regset s390_compat_regsets[] = { .get = s390_fpregs_get, .set = s390_fpregs_set, }, + [REGSET_LAST_BREAK] = { + .core_note_type = NT_S390_LAST_BREAK, + .n = 1, + .size = sizeof(long), + .align = sizeof(long), + .get = s390_compat_last_break_get, + }, [REGSET_GENERAL_EXTENDED] = { .core_note_type = NT_S390_HIGH_GPRS, .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t), -- cgit v1.2.3