From 6749ef0b8b1f8aa72cc93c874edef39f4c0533ba Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 21 May 2012 10:44:12 +1000 Subject: Revert "powerpc/hw-breakpoint: Use generic hw-breakpoint interfaces for new PPC ptrace flags" This reverts commit 1b788400bbcbfe25280dc0b8000d2142bfe3be3b. It causes oopses when passed incorrect arguments and has a design fault using IPIs with interrupts disabled. Signed-off-by: Benjamin Herrenschmidt --- --- arch/powerpc/kernel/ptrace.c | 77 ++++---------------------------------------- 1 file changed, 6 insertions(+), 71 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 8643ac89023..ac3cb008fb3 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -1336,12 +1336,6 @@ static int set_dac_range(struct task_struct *child, static long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info) { -#ifdef CONFIG_HAVE_HW_BREAKPOINT - int len = 0; - struct thread_struct *thread = &(child->thread); - struct perf_event *bp; - struct perf_event_attr attr; -#endif /* CONFIG_HAVE_HW_BREAKPOINT */ #ifndef CONFIG_PPC_ADV_DEBUG_REGS unsigned long dabr; #endif @@ -1385,9 +1379,13 @@ static long ppc_set_hwdebug(struct task_struct *child, */ if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 || (bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 || + bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT || bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE) return -EINVAL; + if (child->thread.dabr) + return -ENOSPC; + if ((unsigned long)bp_info->addr >= TASK_SIZE) return -EIO; @@ -1397,63 +1395,15 @@ static long ppc_set_hwdebug(struct task_struct *child, dabr |= DABR_DATA_READ; if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE) dabr |= DABR_DATA_WRITE; -#ifdef CONFIG_HAVE_HW_BREAKPOINT - if (ptrace_get_breakpoints(child) < 0) - return -ESRCH; - - /* - * Check if the request is for 'range' breakpoints. We can - * support it if range < 8 bytes. - */ - if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE) { - len = bp_info->addr2 - bp_info->addr; - } else if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) { - ptrace_put_breakpoints(child); - return -EINVAL; - } - bp = thread->ptrace_bps[0]; - if (bp) { - ptrace_put_breakpoints(child); - return -ENOSPC; - } - - /* Create a new breakpoint request if one doesn't exist already */ - hw_breakpoint_init(&attr); - attr.bp_addr = (unsigned long)bp_info->addr & ~HW_BREAKPOINT_ALIGN; - attr.bp_len = len; - arch_bp_generic_fields(dabr & (DABR_DATA_WRITE | DABR_DATA_READ), - &attr.bp_type); - - thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr, - ptrace_triggered, NULL, child); - if (IS_ERR(bp)) { - thread->ptrace_bps[0] = NULL; - ptrace_put_breakpoints(child); - return PTR_ERR(bp); - } - - ptrace_put_breakpoints(child); - return 1; -#endif /* CONFIG_HAVE_HW_BREAKPOINT */ - - if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) - return -EINVAL; - - if (child->thread.dabr) - return -ENOSPC; child->thread.dabr = dabr; + return 1; #endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */ } static long ppc_del_hwdebug(struct task_struct *child, long addr, long data) { -#ifdef CONFIG_HAVE_HW_BREAKPOINT - int ret = 0; - struct thread_struct *thread = &(child->thread); - struct perf_event *bp; -#endif /* CONFIG_HAVE_HW_BREAKPOINT */ #ifdef CONFIG_PPC_ADV_DEBUG_REGS int rc; @@ -1473,25 +1423,10 @@ static long ppc_del_hwdebug(struct task_struct *child, long addr, long data) #else if (data != 1) return -EINVAL; - -#ifdef CONFIG_HAVE_HW_BREAKPOINT - if (ptrace_get_breakpoints(child) < 0) - return -ESRCH; - - bp = thread->ptrace_bps[0]; - if (bp) { - unregister_hw_breakpoint(bp); - thread->ptrace_bps[0] = NULL; - } else - ret = -ENOENT; - ptrace_put_breakpoints(child); - return ret; -#else /* CONFIG_HAVE_HW_BREAKPOINT */ if (child->thread.dabr == 0) return -ENOENT; child->thread.dabr = 0; -#endif /* CONFIG_HAVE_HW_BREAKPOINT */ return 0; #endif @@ -1598,7 +1533,7 @@ long arch_ptrace(struct task_struct *child, long request, dbginfo.data_bp_alignment = 4; #endif dbginfo.sizeof_condition = 0; - dbginfo.features = PPC_DEBUG_FEATURE_DATA_BP_RANGE; + dbginfo.features = 0; #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ if (!access_ok(VERIFY_WRITE, datavp, -- cgit v1.2.3