From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kyle McMartin Date: Wed, 19 Dec 2007 16:42:04 +0000 Subject: Re: [ia64] BUG: sleeping in atomic Message-Id: <20071219164204.GA18161@fattire.cabal.ca> List-Id: References: <20071219055430.GV4396912@sgi.com> In-Reply-To: <20071219055430.GV4396912@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Chinner Cc: lkml , tony.luck@intel.com, linux-ia64@vger.kernel.org On Wed, Dec 19, 2007 at 04:54:30PM +1100, David Chinner wrote: > [ 5667.086055] BUG: sleeping function called from invalid context at kernel/fork.c:401 > The problem is that mmput is called under the read_lock by find_thread_for_addr... The comment above seems to indicate that gdb needs to be able to access any child tasks register backing store memory... This seems pretty broken. cheers, Kyle --- Who knows, maybe gdb is saner now? diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 2e96f17..b609704 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -1418,7 +1418,7 @@ asmlinkage long sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) { struct pt_regs *pt; - unsigned long urbs_end, peek_or_poke; + unsigned long urbs_end; struct task_struct *child; struct switch_stack *sw; long ret; @@ -1430,23 +1430,12 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data) goto out; } - peek_or_poke = (request = PTRACE_PEEKTEXT - || request = PTRACE_PEEKDATA - || request = PTRACE_POKETEXT - || request = PTRACE_POKEDATA); - ret = -ESRCH; - read_lock(&tasklist_lock); - { - child = find_task_by_pid(pid); - if (child) { - if (peek_or_poke) - child = find_thread_for_addr(child, addr); - get_task_struct(child); - } - } - read_unlock(&tasklist_lock); - if (!child) + child = ptrace_get_task_struct(pid); + if (IS_ERR(child)) { + ret = PTR_ERR(child); goto out; + } + ret = -EPERM; if (pid = 1) /* no messing around with init! */ goto out_tsk;