Commit 25e39e32 authored Apr 25, 2019 by Thomas Gleixner

livepatch: Simplify stack trace retrieval



Replace the indirection through struct stack_trace by using the storage
array based interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094803.437950229@linutronix.de

parent 9f50c91b

kernel/livepatch/transition.c

+9 −13

Original line number	Diff line number	Diff line
		@@ -202,15 +202,15 @@ void klp_update_patch_state(struct task_struct *task)
		* Determine whether the given stack trace includes any references to a
		* to-be-patched or to-be-unpatched function.
		*/
		static int klp_check_stack_func(struct klp_func *func,
		struct stack_trace *trace)
		static int klp_check_stack_func(struct klp_func func, unsigned long entries,
		unsigned int nr_entries)
		{
		unsigned long func_addr, func_size, address;
		struct klp_ops *ops;
		int i;

		for (i = 0; i < trace->nr_entries; i++) {
		address = trace->entries[i];
		for (i = 0; i < nr_entries; i++) {
		address = entries[i];

		if (klp_target_state == KLP_UNPATCHED) {
		/*
		@@ -254,29 +254,25 @@ static int klp_check_stack_func(struct klp_func *func,
		static int klp_check_stack(struct task_struct task, char err_buf)
		{
		static unsigned long entries[MAX_STACK_ENTRIES];
		struct stack_trace trace;
		struct klp_object *obj;
		struct klp_func *func;
		int ret;
		int ret, nr_entries;

		trace.skip = 0;
		trace.nr_entries = 0;
		trace.max_entries = MAX_STACK_ENTRIES;
		trace.entries = entries;
		ret = save_stack_trace_tsk_reliable(task, &trace);
		ret = stack_trace_save_tsk_reliable(task, entries, ARRAY_SIZE(entries));
		WARN_ON_ONCE(ret == -ENOSYS);
		if (ret) {
		if (ret < 0) {
		snprintf(err_buf, STACK_ERR_BUF_SIZE,
		"%s: %s:%d has an unreliable stack\n",
		__func__, task->comm, task->pid);
		return ret;
		}
		nr_entries = ret;

		klp_for_each_object(klp_transition_patch, obj) {
		if (!obj->patched)
		continue;
		klp_for_each_func(obj, func) {
		ret = klp_check_stack_func(func, &trace);
		ret = klp_check_stack_func(func, entries, nr_entries);
		if (ret) {
		snprintf(err_buf, STACK_ERR_BUF_SIZE,
		"%s: %s:%d is sleeping on function %s\n",