Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752619AbYKYIFm (ORCPT ); Tue, 25 Nov 2008 03:05:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751178AbYKYIFe (ORCPT ); Tue, 25 Nov 2008 03:05:34 -0500 Received: from mga11.intel.com ([192.55.52.93]:38367 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbYKYIFd (ORCPT ); Tue, 25 Nov 2008 03:05:33 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.33,663,1220252400"; d="scan'208";a="407756232" Date: Tue, 25 Nov 2008 09:05:27 +0100 From: Markus Metzger To: hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de Cc: markus.t.metzger@intel.com, markus.t.metzger@gmail.com, roland@redhat.com, akpm@linux-foundation.org, mtk.manpages@gmail.com, eranian@googlemail.com, juan.villacis@intel.com Subject: [patch 6/9] x86, bts, ptrace: move BTS buffer allocation from ds.c into ptrace.c Message-ID: <20081125090527.A31252@sedona.ch.intel.com> Mime-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.2.5i Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8556 Lines: 301 Require pre-allocated buffers in ds.h. Move the BTS buffer allocation for ptrace into ptrace.c. The pointer to the allocated buffer is stored in the traced task's task_struct together with the handle returned by ds_request_bts(). Removes memory accounting code. Signed-off-by: Markus Metzger --- Index: ftrace/arch/x86/kernel/ds.c =================================================================== --- ftrace.orig/arch/x86/kernel/ds.c 2008-11-25 08:18:01.000000000 +0100 +++ ftrace/arch/x86/kernel/ds.c 2008-11-25 08:18:03.000000000 +0100 @@ -7,13 +7,12 @@ * * It manages: * - per-thread and per-cpu allocation of BTS and PEBS - * - buffer memory allocation (optional) - * - buffer overflow handling + * - buffer overflow handling (to be done) * - buffer access * * It assumes: - * - get_task_struct on all parameter tasks - * - current is allowed to trace parameter tasks + * - get_task_struct on all traced tasks + * - current is allowed to trace tasks * * * Copyright (C) 2007-2008 Intel Corporation. @@ -57,8 +56,6 @@ /* the buffer provided on ds_request() and its size in bytes */ void *buffer; size_t size; - /* the number of allocated pages for on-request allocated buffers */ - unsigned int pages; }; struct bts_tracer { @@ -141,8 +138,7 @@ /* - * Locking is done only for allocating BTS or PEBS resources and for - * guarding context and buffer memory allocation. + * Locking is done only for allocating BTS or PEBS resources. */ static spinlock_t ds_lock = __SPIN_LOCK_UNLOCKED(ds_lock); @@ -292,50 +288,6 @@ } -/* - * Allocate a non-pageable buffer of the parameter size. - * Checks the memory and the locked memory rlimit. - * - * Returns the buffer, if successful; - * NULL, if out of memory or rlimit exceeded. - * - * size: the requested buffer size in bytes - * pages (out): if not NULL, contains the number of pages reserved - */ -static inline void *ds_allocate_buffer(size_t size, unsigned int *pages) -{ - unsigned long rlim, vm, pgsz; - void *buffer = NULL; - - pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT; - - down_write(¤t->mm->mmap_sem); - - rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT; - vm = current->mm->total_vm + pgsz; - if (rlim < vm) - goto out; - - rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT; - vm = current->mm->locked_vm + pgsz; - if (rlim < vm) - goto out; - - buffer = kzalloc(size, GFP_KERNEL); - if (!buffer) - goto out; - - current->mm->total_vm += pgsz; - current->mm->locked_vm += pgsz; - - if (pages) - *pages = pgsz; - - out: - up_write(¤t->mm->mmap_sem); - return buffer; -} - static void ds_install_ds_config(struct ds_context *context, enum ds_qualifier qual, void *base, size_t size, size_t ith) @@ -382,6 +334,10 @@ if (!ds_cfg.sizeof_ds) goto out; + error = -EINVAL; + if (!base) + goto out; + /* we require some space to do alignment adjustments below */ error = -EINVAL; if (size < (DS_ALIGNMENT + ds_cfg.sizeof_rec[qual])) @@ -395,13 +351,6 @@ goto out; } - error = -ENOMEM; - if (!base) { - base = ds_allocate_buffer(size, &tracer->pages); - if (!base) - goto out; - } - tracer->buffer = base; tracer->size = size; @@ -466,7 +415,7 @@ return tracer; out_tracer: - (void)ds_release_bts(tracer); + kfree(tracer); out: return ERR_PTR(error); } @@ -496,31 +445,18 @@ return tracer; out_tracer: - (void)ds_release_pebs(tracer); + kfree(tracer); out: return ERR_PTR(error); } static void ds_release(struct ds_tracer *tracer, enum ds_qualifier qual) { - if (tracer->context) { - BUG_ON(tracer->context->owner[qual] != tracer); - tracer->context->owner[qual] = NULL; - - put_tracer(tracer->context->task); - ds_put_context(tracer->context); - } + BUG_ON(tracer->context->owner[qual] != tracer); + tracer->context->owner[qual] = NULL; - if (tracer->pages) { - kfree(tracer->buffer); - - down_write(¤t->mm->mmap_sem); - - current->mm->total_vm -= tracer->pages; - current->mm->locked_vm -= tracer->pages; - - up_write(¤t->mm->mmap_sem); - } + put_tracer(tracer->context->task); + ds_put_context(tracer->context); } int ds_release_bts(struct bts_tracer *tracer) Index: ftrace/arch/x86/kernel/ptrace.c =================================================================== --- ftrace.orig/arch/x86/kernel/ptrace.c 2008-11-25 08:18:01.000000000 +0100 +++ ftrace/arch/x86/kernel/ptrace.c 2008-11-25 08:18:03.000000000 +0100 @@ -758,6 +758,10 @@ bts_ovfl_callback_t ovfl = NULL; unsigned int sig = 0; + error = -EINVAL; + if (cfg.size < (10 * bts_cfg.sizeof_bts)) + goto errout; + if (cfg.flags & PTRACE_BTS_O_SIGNAL) { if (!cfg.signal) goto errout; @@ -768,14 +772,26 @@ sig = cfg.signal; } - if (child->bts) + if (child->bts) { (void)ds_release_bts(child->bts); + kfree(child->bts_buffer); + + child->bts = NULL; + child->bts_buffer = NULL; + } + + error = -ENOMEM; + child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL); + if (!child->bts_buffer) + goto errout; - child->bts = ds_request_bts(child, /* base = */ NULL, cfg.size, + child->bts = ds_request_bts(child, child->bts_buffer, cfg.size, ovfl, /* th = */ (size_t)-1); if (IS_ERR(child->bts)) { error = PTR_ERR(child->bts); + kfree(child->bts_buffer); child->bts = NULL; + child->bts_buffer = NULL; goto errout; } @@ -972,6 +988,8 @@ #ifdef CONFIG_X86_PTRACE_BTS if (child->bts) { (void)ds_release_bts(child->bts); + kfree(child->bts_buffer); + child->bts_buffer = NULL; child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask; if (!child->thread.debugctlmsr) Index: ftrace/arch/x86/include/asm/ds.h =================================================================== --- ftrace.orig/arch/x86/include/asm/ds.h 2008-11-25 08:18:01.000000000 +0100 +++ ftrace/arch/x86/include/asm/ds.h 2008-11-25 08:18:03.000000000 +0100 @@ -7,13 +7,12 @@ * * It manages: * - per-thread and per-cpu allocation of BTS and PEBS - * - buffer memory allocation (optional) - * - buffer overflow handling + * - buffer overflow handling (to be done) * - buffer access * * It assumes: - * - get_task_struct on all parameter tasks - * - current is allowed to trace parameter tasks + * - get_task_struct on all traced tasks + * - current is allowed to trace tasks * * * Copyright (C) 2007-2008 Intel Corporation. @@ -54,8 +53,7 @@ * task: the task to request recording for; * NULL for per-cpu recording on the current cpu * base: the base pointer for the (non-pageable) buffer; - * NULL if buffer allocation requested - * size: the size of the requested or provided buffer in bytes + * size: the size of the provided buffer in bytes * ovfl: pointer to a function to be called on buffer overflow; * NULL if cyclic buffer requested * th: the interrupt threshold in records from the end of the buffer; @@ -72,8 +70,6 @@ /* * Release BTS or PEBS resources * - * Frees buffers allocated on ds_request. - * * Returns 0 on success; -Eerrno otherwise * * tracer: the tracer handle returned from ds_request_~() Index: ftrace/include/linux/sched.h =================================================================== --- ftrace.orig/include/linux/sched.h 2008-11-25 08:18:01.000000000 +0100 +++ ftrace/include/linux/sched.h 2008-11-25 08:18:03.000000000 +0100 @@ -1165,6 +1165,10 @@ * This field actually belongs to the ptracer task. */ struct bts_tracer *bts; + /* + * The buffer to hold the BTS data. + */ + void *bts_buffer; #endif /* CONFIG_X86_PTRACE_BTS */ /* PID/PID hash table linkage. */ --------------------------------------------------------------------- Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen Germany Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer Registergericht: Muenchen HRB 47456 Ust.-IdNr. 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