From 9f6b3c2c30cfbb1166ce7e74a8f9fd93ae19d2de Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 9 Nov 2009 21:03:43 +0100 Subject: hw-breakpoints: Fix broken a.out format dump Fix the broken a.out format dump. For now we only dump the ptrace breakpoints. TODO: Dump every perf breakpoints for the current thread, not only ptrace based ones. Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: "K. Prasad" --- arch/x86/include/asm/a.out-core.h | 10 ++-------- arch/x86/include/asm/debugreg.h | 2 ++ arch/x86/kernel/hw_breakpoint.c | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/a.out-core.h b/arch/x86/include/asm/a.out-core.h index fc4685d..7a15588 100644 --- a/arch/x86/include/asm/a.out-core.h +++ b/arch/x86/include/asm/a.out-core.h @@ -17,6 +17,7 @@ #include #include +#include /* * fill in the user structure for an a.out core dump @@ -32,14 +33,7 @@ static inline void aout_dump_thread(struct pt_regs *regs, struct user *dump) >> PAGE_SHIFT; dump->u_dsize -= dump->u_tsize; dump->u_ssize = 0; - dump->u_debugreg[0] = current->thread.debugreg[0]; - dump->u_debugreg[1] = current->thread.debugreg[1]; - dump->u_debugreg[2] = current->thread.debugreg[2]; - dump->u_debugreg[3] = current->thread.debugreg[3]; - dump->u_debugreg[4] = 0; - dump->u_debugreg[5] = 0; - dump->u_debugreg[6] = current->thread.debugreg6; - dump->u_debugreg[7] = current->thread.debugreg7; + aout_dump_debugregs(dump); if (dump->start_stack < TASK_SIZE) dump->u_ssize = ((unsigned long)(TASK_SIZE - dump->start_stack)) diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h index 9a3333c..f1b673f 100644 --- a/arch/x86/include/asm/debugreg.h +++ b/arch/x86/include/asm/debugreg.h @@ -89,6 +89,8 @@ static inline void hw_breakpoint_disable(void) set_debugreg(0UL, 3); } +extern void aout_dump_debugregs(struct user *dump); + #ifdef CONFIG_KVM extern void hw_breakpoint_restore(void); #endif diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index e622620..57dcee5 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -376,6 +376,41 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp, } /* + * Dump the debug register contents to the user. + * We can't dump our per cpu values because it + * may contain cpu wide breakpoint, something that + * doesn't belong to the current task. + * + * TODO: include non-ptrace user breakpoints (perf) + */ +void aout_dump_debugregs(struct user *dump) +{ + int i; + int dr7 = 0; + struct perf_event *bp; + struct arch_hw_breakpoint *info; + struct thread_struct *thread = ¤t->thread; + + for (i = 0; i < HBP_NUM; i++) { + bp = thread->ptrace_bps[i]; + + if (bp && !bp->attr.disabled) { + dump->u_debugreg[i] = bp->attr.bp_addr; + info = counter_arch_bp(bp); + dr7 |= encode_dr7(i, info->len, info->type); + } else { + dump->u_debugreg[i] = 0; + } + } + + dump->u_debugreg[4] = 0; + dump->u_debugreg[5] = 0; + dump->u_debugreg[6] = current->thread.debugreg6; + + dump->u_debugreg[7] = dr7; +} + +/* * Release the user breakpoints used by ptrace */ void flush_ptrace_hw_breakpoint(struct task_struct *tsk) -- cgit v1.1