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-rw-r--r--kernel/events/core.c49
-rw-r--r--kernel/events/uprobes.c461
-rw-r--r--kernel/trace/ftrace.c8
-rw-r--r--kernel/trace/ring_buffer.c4
-rw-r--r--kernel/trace/trace.c33
-rw-r--r--kernel/trace/trace.h8
-rw-r--r--kernel/trace/trace_functions_graph.c2
-rw-r--r--kernel/trace/trace_output.c2
8 files changed, 313 insertions, 254 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d7d71d6ec97..f1cf0edeb39 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1645,6 +1645,8 @@ perf_install_in_context(struct perf_event_context *ctx,
lockdep_assert_held(&ctx->mutex);
event->ctx = ctx;
+ if (event->cpu != -1)
+ event->cpu = cpu;
if (!task) {
/*
@@ -6252,6 +6254,8 @@ SYSCALL_DEFINE5(perf_event_open,
}
}
+ get_online_cpus();
+
event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
NULL, NULL);
if (IS_ERR(event)) {
@@ -6304,7 +6308,7 @@ SYSCALL_DEFINE5(perf_event_open,
/*
* Get the target context (task or percpu):
*/
- ctx = find_get_context(pmu, task, cpu);
+ ctx = find_get_context(pmu, task, event->cpu);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
goto err_alloc;
@@ -6377,20 +6381,23 @@ SYSCALL_DEFINE5(perf_event_open,
mutex_lock(&ctx->mutex);
if (move_group) {
- perf_install_in_context(ctx, group_leader, cpu);
+ synchronize_rcu();
+ perf_install_in_context(ctx, group_leader, event->cpu);
get_ctx(ctx);
list_for_each_entry(sibling, &group_leader->sibling_list,
group_entry) {
- perf_install_in_context(ctx, sibling, cpu);
+ perf_install_in_context(ctx, sibling, event->cpu);
get_ctx(ctx);
}
}
- perf_install_in_context(ctx, event, cpu);
+ perf_install_in_context(ctx, event, event->cpu);
++ctx->generation;
perf_unpin_context(ctx);
mutex_unlock(&ctx->mutex);
+ put_online_cpus();
+
event->owner = current;
mutex_lock(&current->perf_event_mutex);
@@ -6419,6 +6426,7 @@ err_context:
err_alloc:
free_event(event);
err_task:
+ put_online_cpus();
if (task)
put_task_struct(task);
err_group_fd:
@@ -6479,6 +6487,39 @@ err:
}
EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
+void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
+{
+ struct perf_event_context *src_ctx;
+ struct perf_event_context *dst_ctx;
+ struct perf_event *event, *tmp;
+ LIST_HEAD(events);
+
+ src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
+ dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
+
+ mutex_lock(&src_ctx->mutex);
+ list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
+ event_entry) {
+ perf_remove_from_context(event);
+ put_ctx(src_ctx);
+ list_add(&event->event_entry, &events);
+ }
+ mutex_unlock(&src_ctx->mutex);
+
+ synchronize_rcu();
+
+ mutex_lock(&dst_ctx->mutex);
+ list_for_each_entry_safe(event, tmp, &events, event_entry) {
+ list_del(&event->event_entry);
+ if (event->state >= PERF_EVENT_STATE_OFF)
+ event->state = PERF_EVENT_STATE_INACTIVE;
+ perf_install_in_context(dst_ctx, event, dst_cpu);
+ get_ctx(dst_ctx);
+ }
+ mutex_unlock(&dst_ctx->mutex);
+}
+EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
+
static void sync_child_event(struct perf_event *child_event,
struct task_struct *child)
{
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 985be4d80fe..f93532748bc 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -38,13 +38,29 @@
#define UINSNS_PER_PAGE (PAGE_SIZE/UPROBE_XOL_SLOT_BYTES)
#define MAX_UPROBE_XOL_SLOTS UINSNS_PER_PAGE
-static struct srcu_struct uprobes_srcu;
static struct rb_root uprobes_tree = RB_ROOT;
static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */
#define UPROBES_HASH_SZ 13
+/*
+ * We need separate register/unregister and mmap/munmap lock hashes because
+ * of mmap_sem nesting.
+ *
+ * uprobe_register() needs to install probes on (potentially) all processes
+ * and thus needs to acquire multiple mmap_sems (consequtively, not
+ * concurrently), whereas uprobe_mmap() is called while holding mmap_sem
+ * for the particular process doing the mmap.
+ *
+ * uprobe_register()->register_for_each_vma() needs to drop/acquire mmap_sem
+ * because of lock order against i_mmap_mutex. This means there's a hole in
+ * the register vma iteration where a mmap() can happen.
+ *
+ * Thus uprobe_register() can race with uprobe_mmap() and we can try and
+ * install a probe where one is already installed.
+ */
+
/* serialize (un)register */
static struct mutex uprobes_mutex[UPROBES_HASH_SZ];
@@ -61,17 +77,6 @@ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
*/
static atomic_t uprobe_events = ATOMIC_INIT(0);
-/*
- * Maintain a temporary per vma info that can be used to search if a vma
- * has already been handled. This structure is introduced since extending
- * vm_area_struct wasnt recommended.
- */
-struct vma_info {
- struct list_head probe_list;
- struct mm_struct *mm;
- loff_t vaddr;
-};
-
struct uprobe {
struct rb_node rb_node; /* node in the rb tree */
atomic_t ref;
@@ -100,7 +105,8 @@ static bool valid_vma(struct vm_area_struct *vma, bool is_register)
if (!is_register)
return true;
- if ((vma->vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)) == (VM_READ|VM_EXEC))
+ if ((vma->vm_flags & (VM_HUGETLB|VM_READ|VM_WRITE|VM_EXEC|VM_SHARED))
+ == (VM_READ|VM_EXEC))
return true;
return false;
@@ -129,33 +135,17 @@ static loff_t vma_address(struct vm_area_struct *vma, loff_t offset)
static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage)
{
struct mm_struct *mm = vma->vm_mm;
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *ptep;
- spinlock_t *ptl;
unsigned long addr;
- int err = -EFAULT;
+ spinlock_t *ptl;
+ pte_t *ptep;
addr = page_address_in_vma(page, vma);
if (addr == -EFAULT)
- goto out;
-
- pgd = pgd_offset(mm, addr);
- if (!pgd_present(*pgd))
- goto out;
-
- pud = pud_offset(pgd, addr);
- if (!pud_present(*pud))
- goto out;
-
- pmd = pmd_offset(pud, addr);
- if (!pmd_present(*pmd))
- goto out;
+ return -EFAULT;
- ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ ptep = page_check_address(page, mm, addr, &ptl, 0);
if (!ptep)
- goto out;
+ return -EAGAIN;
get_page(kpage);
page_add_new_anon_rmap(kpage, vma, addr);
@@ -174,10 +164,8 @@ static int __replace_page(struct vm_area_struct *vma, struct page *page, struct
try_to_free_swap(page);
put_page(page);
pte_unmap_unlock(ptep, ptl);
- err = 0;
-out:
- return err;
+ return 0;
}
/**
@@ -222,9 +210,8 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
void *vaddr_old, *vaddr_new;
struct vm_area_struct *vma;
struct uprobe *uprobe;
- loff_t addr;
int ret;
-
+retry:
/* Read the page with vaddr into memory */
ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
if (ret <= 0)
@@ -246,10 +233,6 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
if (mapping != vma->vm_file->f_mapping)
goto put_out;
- addr = vma_address(vma, uprobe->offset);
- if (vaddr != (unsigned long)addr)
- goto put_out;
-
ret = -ENOMEM;
new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
if (!new_page)
@@ -267,11 +250,7 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
vaddr_new = kmap_atomic(new_page);
memcpy(vaddr_new, vaddr_old, PAGE_SIZE);
-
- /* poke the new insn in, ASSUMES we don't cross page boundary */
- vaddr &= ~PAGE_MASK;
- BUG_ON(vaddr + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
- memcpy(vaddr_new + vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
+ memcpy(vaddr_new + (vaddr & ~PAGE_MASK), &opcode, UPROBE_SWBP_INSN_SIZE);
kunmap_atomic(vaddr_new);
kunmap_atomic(vaddr_old);
@@ -291,6 +270,8 @@ unlock_out:
put_out:
put_page(old_page);
+ if (unlikely(ret == -EAGAIN))
+ goto retry;
return ret;
}
@@ -312,7 +293,7 @@ static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_
void *vaddr_new;
int ret;
- ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &page, NULL);
+ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
if (ret <= 0)
return ret;
@@ -333,10 +314,20 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
uprobe_opcode_t opcode;
int result;
+ if (current->mm == mm) {
+ pagefault_disable();
+ result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr,
+ sizeof(opcode));
+ pagefault_enable();
+
+ if (likely(result == 0))
+ goto out;
+ }
+
result = read_opcode(mm, vaddr, &opcode);
if (result)
return result;
-
+out:
if (is_swbp_insn(&opcode))
return 1;
@@ -355,7 +346,9 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
int result;
-
+ /*
+ * See the comment near uprobes_hash().
+ */
result = is_swbp_at_addr(mm, vaddr);
if (result == 1)
return -EEXIST;
@@ -520,7 +513,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
uprobe->inode = igrab(inode);
uprobe->offset = offset;
init_rwsem(&uprobe->consumer_rwsem);
- INIT_LIST_HEAD(&uprobe->pending_list);
/* add to uprobes_tree, sorted on inode:offset */
cur_uprobe = insert_uprobe(uprobe);
@@ -588,20 +580,22 @@ static bool consumer_del(struct uprobe *uprobe, struct uprobe_consumer *uc)
}
static int
-__copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *insn,
- unsigned long nbytes, unsigned long offset)
+__copy_insn(struct address_space *mapping, struct file *filp, char *insn,
+ unsigned long nbytes, loff_t offset)
{
- struct file *filp = vma->vm_file;
struct page *page;
void *vaddr;
- unsigned long off1;
- unsigned long idx;
+ unsigned long off;
+ pgoff_t idx;
if (!filp)
return -EINVAL;
- idx = (unsigned long)(offset >> PAGE_CACHE_SHIFT);
- off1 = offset &= ~PAGE_MASK;
+ if (!mapping->a_ops->readpage)
+ return -EIO;
+
+ idx = offset >> PAGE_CACHE_SHIFT;
+ off = offset & ~PAGE_MASK;
/*
* Ensure that the page that has the original instruction is
@@ -612,22 +606,20 @@ __copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *ins
return PTR_ERR(page);
vaddr = kmap_atomic(page);
- memcpy(insn, vaddr + off1, nbytes);
+ memcpy(insn, vaddr + off, nbytes);
kunmap_atomic(vaddr);
page_cache_release(page);
return 0;
}
-static int
-copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
+static int copy_insn(struct uprobe *uprobe, struct file *filp)
{
struct address_space *mapping;
unsigned long nbytes;
int bytes;
- addr &= ~PAGE_MASK;
- nbytes = PAGE_SIZE - addr;
+ nbytes = PAGE_SIZE - (uprobe->offset & ~PAGE_MASK);
mapping = uprobe->inode->i_mapping;
/* Instruction at end of binary; copy only available bytes */
@@ -638,13 +630,13 @@ copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
/* Instruction at the page-boundary; copy bytes in second page */
if (nbytes < bytes) {
- if (__copy_insn(mapping, vma, uprobe->arch.insn + nbytes,
- bytes - nbytes, uprobe->offset + nbytes))
- return -ENOMEM;
-
+ int err = __copy_insn(mapping, filp, uprobe->arch.insn + nbytes,
+ bytes - nbytes, uprobe->offset + nbytes);
+ if (err)
+ return err;
bytes = nbytes;
}
- return __copy_insn(mapping, vma, uprobe->arch.insn, bytes, uprobe->offset);
+ return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset);
}
/*
@@ -672,9 +664,8 @@ copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
*/
static int
install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
- struct vm_area_struct *vma, loff_t vaddr)
+ struct vm_area_struct *vma, unsigned long vaddr)
{
- unsigned long addr;
int ret;
/*
@@ -687,20 +678,22 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
if (!uprobe->consumers)
return -EEXIST;
- addr = (unsigned long)vaddr;
-
if (!(uprobe->flags & UPROBE_COPY_INSN)) {
- ret = copy_insn(uprobe, vma, addr);
+ ret = copy_insn(uprobe, vma->vm_file);
if (ret)
return ret;
if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
- return -EEXIST;
+ return -ENOTSUPP;
- ret = arch_uprobe_analyze_insn(&uprobe->arch, mm);
+ ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
if (ret)
return ret;
+ /* write_opcode() assumes we don't cross page boundary */
+ BUG_ON((uprobe->offset & ~PAGE_MASK) +
+ UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
+
uprobe->flags |= UPROBE_COPY_INSN;
}
@@ -713,7 +706,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
* Hence increment before and decrement on failure.
*/
atomic_inc(&mm->uprobes_state.count);
- ret = set_swbp(&uprobe->arch, mm, addr);
+ ret = set_swbp(&uprobe->arch, mm, vaddr);
if (ret)
atomic_dec(&mm->uprobes_state.count);
@@ -721,27 +714,21 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
}
static void
-remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, loff_t vaddr)
+remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)
{
- if (!set_orig_insn(&uprobe->arch, mm, (unsigned long)vaddr, true))
+ if (!set_orig_insn(&uprobe->arch, mm, vaddr, true))
atomic_dec(&mm->uprobes_state.count);
}
/*
- * There could be threads that have hit the breakpoint and are entering the
- * notifier code and trying to acquire the uprobes_treelock. The thread
- * calling delete_uprobe() that is removing the uprobe from the rb_tree can
- * race with these threads and might acquire the uprobes_treelock compared
- * to some of the breakpoint hit threads. In such a case, the breakpoint
- * hit threads will not find the uprobe. The current unregistering thread
- * waits till all other threads have hit a breakpoint, to acquire the
- * uprobes_treelock before the uprobe is removed from the rbtree.
+ * There could be threads that have already hit the breakpoint. They
+ * will recheck the current insn and restart if find_uprobe() fails.
+ * See find_active_uprobe().
*/
static void delete_uprobe(struct uprobe *uprobe)
{
unsigned long flags;
- synchronize_srcu(&uprobes_srcu);
spin_lock_irqsave(&uprobes_treelock, flags);
rb_erase(&uprobe->rb_node, &uprobes_tree);
spin_unlock_irqrestore(&uprobes_treelock, flags);
@@ -750,139 +737,135 @@ static void delete_uprobe(struct uprobe *uprobe)
atomic_dec(&uprobe_events);
}
-static struct vma_info *
-__find_next_vma_info(struct address_space *mapping, struct list_head *head,
- struct vma_info *vi, loff_t offset, bool is_register)
+struct map_info {
+ struct map_info *next;
+ struct mm_struct *mm;
+ unsigned long vaddr;
+};
+
+static inline struct map_info *free_map_info(struct map_info *info)
+{
+ struct map_info *next = info->next;
+ kfree(info);
+ return next;
+}
+
+static struct map_info *
+build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
{
+ unsigned long pgoff = offset >> PAGE_SHIFT;
struct prio_tree_iter iter;
struct vm_area_struct *vma;
- struct vma_info *tmpvi;
- unsigned long pgoff;
- int existing_vma;
- loff_t vaddr;
-
- pgoff = offset >> PAGE_SHIFT;
+ struct map_info *curr = NULL;
+ struct map_info *prev = NULL;
+ struct map_info *info;
+ int more = 0;
+ again:
+ mutex_lock(&mapping->i_mmap_mutex);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
if (!valid_vma(vma, is_register))
continue;
- existing_vma = 0;
- vaddr = vma_address(vma, offset);
-
- list_for_each_entry(tmpvi, head, probe_list) {
- if (tmpvi->mm == vma->vm_mm && tmpvi->vaddr == vaddr) {
- existing_vma = 1;
- break;
- }
+ if (!prev && !more) {
+ /*
+ * Needs GFP_NOWAIT to avoid i_mmap_mutex recursion through
+ * reclaim. This is optimistic, no harm done if it fails.
+ */
+ prev = kmalloc(sizeof(struct map_info),
+ GFP_NOWAIT | __GFP_NOMEMALLOC | __GFP_NOWARN);
+ if (prev)
+ prev->next = NULL;
}
-
- /*
- * Another vma needs a probe to be installed. However skip
- * installing the probe if the vma is about to be unlinked.
- */
- if (!existing_vma && atomic_inc_not_zero(&vma->vm_mm->mm_users)) {
- vi->mm = vma->vm_mm;
- vi->vaddr = vaddr;
- list_add(&vi->probe_list, head);
-
- return vi;
+ if (!prev) {
+ more++;
+ continue;
}
- }
- return NULL;
-}
-
-/*
- * Iterate in the rmap prio tree and find a vma where a probe has not
- * yet been inserted.
- */
-static struct vma_info *
-find_next_vma_info(struct address_space *mapping, struct list_head *head,
- loff_t offset, bool is_register)
-{
- struct vma_info *vi, *retvi;
+ if (!atomic_inc_not_zero(&vma->vm_mm->mm_users))
+ continue;
- vi = kzalloc(sizeof(struct vma_info), GFP_KERNEL);
- if (!vi)
- return ERR_PTR(-ENOMEM);
+ info = prev;
+ prev = prev->next;
+ info->next = curr;
+ curr = info;
- mutex_lock(&mapping->i_mmap_mutex);
- retvi = __find_next_vma_info(mapping, head, vi, offset, is_register);
+ info->mm = vma->vm_mm;
+ info->vaddr = vma_address(vma, offset);
+ }
mutex_unlock(&mapping->i_mmap_mutex);
- if (!retvi)
- kfree(vi);
+ if (!more)
+ goto out;
+
+ prev = curr;
+ while (curr) {
+ mmput(curr->mm);
+ curr = curr->next;
+ }
- return retvi;
+ do {
+ info = kmalloc(sizeof(struct map_info), GFP_KERNEL);
+ if (!info) {
+ curr = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ info->next = prev;
+ prev = info;
+ } while (--more);
+
+ goto again;
+ out:
+ while (prev)
+ prev = free_map_info(prev);
+ return curr;
}
static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
{
- struct list_head try_list;
- struct vm_area_struct *vma;
- struct address_space *mapping;
- struct vma_info *vi, *tmpvi;
- struct mm_struct *mm;
- loff_t vaddr;
- int ret;
+ struct map_info *info;
+ int err = 0;
- mapping = uprobe->inode->i_mapping;
- INIT_LIST_HEAD(&try_list);
+ info = build_map_info(uprobe->inode->i_mapping,
+ uprobe->offset, is_register);
+ if (IS_ERR(info))
+ return PTR_ERR(info);
- ret = 0;
+ while (info) {
+ struct mm_struct *mm = info->mm;
+ struct vm_area_struct *vma;
- for (;;) {
- vi = find_next_vma_info(mapping, &try_list, uprobe->offset, is_register);
- if (!vi)
- break;
+ if (err)
+ goto free;
- if (IS_ERR(vi)) {
- ret = PTR_ERR(vi);
- break;
- }
+ down_write(&mm->mmap_sem);
+ vma = find_vma(mm, (unsigned long)info->vaddr);
+ if (!vma || !valid_vma(vma, is_register))
+ goto unlock;
- mm = vi->mm;
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, (unsigned long)vi->vaddr);
- if (!vma || !valid_vma(vma, is_register)) {
- list_del(&vi->probe_list);
- kfree(vi);
- up_read(&mm->mmap_sem);
- mmput(mm);
- continue;
- }
- vaddr = vma_address(vma, uprobe->offset);
if (vma->vm_file->f_mapping->host != uprobe->inode ||
- vaddr != vi->vaddr) {
- list_del(&vi->probe_list);
- kfree(vi);
- up_read(&mm->mmap_sem);
- mmput(mm);
- continue;
- }
-
- if (is_register)
- ret = install_breakpoint(uprobe, mm, vma, vi->vaddr);
- else
- remove_breakpoint(uprobe, mm, vi->vaddr);
+ vma_address(vma, uprobe->offset) != info->vaddr)
+ goto unlock;
- up_read(&mm->mmap_sem);
- mmput(mm);
if (is_register) {
- if (ret && ret == -EEXIST)
- ret = 0;
- if (ret)
- break;
+ err = install_breakpoint(uprobe, mm, vma, info->vaddr);
+ /*
+ * We can race against uprobe_mmap(), see the
+ * comment near uprobe_hash().
+ */
+ if (err == -EEXIST)
+ err = 0;
+ } else {
+ remove_breakpoint(uprobe, mm, info->vaddr);
}
+ unlock:
+ up_write(&mm->mmap_sem);
+ free:
+ mmput(mm);
+ info = free_map_info(info);
}
- list_for_each_entry_safe(vi, tmpvi, &try_list, probe_list) {
- list_del(&vi->probe_list);
- kfree(vi);
- }
-
- return ret;
+ return err;
}
static int __uprobe_register(struct uprobe *uprobe)
@@ -1048,7 +1031,7 @@ static void build_probe_list(struct inode *inode, struct list_head *head)
int uprobe_mmap(struct vm_area_struct *vma)
{
struct list_head tmp_list;
- struct uprobe *uprobe, *u;
+ struct uprobe *uprobe;
struct inode *inode;
int ret, count;
@@ -1066,12 +1049,9 @@ int uprobe_mmap(struct vm_area_struct *vma)
ret = 0;
count = 0;
- list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
- loff_t vaddr;
-
- list_del(&uprobe->pending_list);
+ list_for_each_entry(uprobe, &tmp_list, pending_list) {
if (!ret) {
- vaddr = vma_address(vma, uprobe->offset);
+ loff_t vaddr = vma_address(vma, uprobe->offset);
if (vaddr < vma->vm_start || vaddr >= vma->vm_end) {
put_uprobe(uprobe);
@@ -1079,8 +1059,10 @@ int uprobe_mmap(struct vm_area_struct *vma)
}
ret = install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
-
- /* Ignore double add: */
+ /*
+ * We can race against uprobe_register(), see the
+ * comment near uprobe_hash().
+ */
if (ret == -EEXIST) {
ret = 0;
@@ -1115,7 +1097,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
struct list_head tmp_list;
- struct uprobe *uprobe, *u;
+ struct uprobe *uprobe;
struct inode *inode;
if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
@@ -1132,11 +1114,8 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon
mutex_lock(uprobes_mmap_hash(inode));
build_probe_list(inode, &tmp_list);
- list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
- loff_t vaddr;
-
- list_del(&uprobe->pending_list);
- vaddr = vma_address(vma, uprobe->offset);
+ list_for_each_entry(uprobe, &tmp_list, pending_list) {
+ loff_t vaddr = vma_address(vma, uprobe->offset);
if (vaddr >= start && vaddr < end) {
/*
@@ -1378,9 +1357,6 @@ void uprobe_free_utask(struct task_struct *t)
{
struct uprobe_task *utask = t->utask;
- if (t->uprobe_srcu_id != -1)
- srcu_read_unlock_raw(&uprobes_srcu, t->uprobe_srcu_id);
-
if (!utask)
return;
@@ -1398,7 +1374,6 @@ void uprobe_free_utask(struct task_struct *t)
void uprobe_copy_process(struct task_struct *t)
{
t->utask = NULL;
- t->uprobe_srcu_id = -1;
}
/*
@@ -1417,7 +1392,6 @@ static struct uprobe_task *add_utask(void)
if (unlikely(!utask))
return NULL;
- utask->active_uprobe = NULL;
current->utask = utask;
return utask;
}
@@ -1479,41 +1453,64 @@ static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)
return false;
}
+static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
+{
+ struct mm_struct *mm = current->mm;
+ struct uprobe *uprobe = NULL;
+ struct vm_area_struct *vma;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, bp_vaddr);
+ if (vma && vma->vm_start <= bp_vaddr) {
+ if (valid_vma(vma, false)) {
+ struct inode *inode;
+ loff_t offset;
+
+ inode = vma->vm_file->f_mapping->host;
+ offset = bp_vaddr - vma->vm_start;
+ offset += (vma->vm_pgoff << PAGE_SHIFT);
+ uprobe = find_uprobe(inode, offset);
+ }
+
+ if (!uprobe)
+ *is_swbp = is_swbp_at_addr(mm, bp_vaddr);
+ } else {
+ *is_swbp = -EFAULT;
+ }
+ up_read(&mm->mmap_sem);
+
+ return uprobe;
+}
+
/*
* Run handler and ask thread to singlestep.
* Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
*/
static void handle_swbp(struct pt_regs *regs)
{
- struct vm_area_struct *vma;
struct uprobe_task *utask;
struct uprobe *uprobe;
- struct mm_struct *mm;
unsigned long bp_vaddr;
+ int uninitialized_var(is_swbp);
- uprobe = NULL;
bp_vaddr = uprobe_get_swbp_addr(regs);
- mm = current->mm;
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, bp_vaddr);
-
- if (vma && vma->vm_start <= bp_vaddr && valid_vma(vma, false)) {
- struct inode *inode;
- loff_t offset;
-
- inode = vma->vm_file->f_mapping->host;
- offset = bp_vaddr - vma->vm_start;
- offset += (vma->vm_pgoff << PAGE_SHIFT);
- uprobe = find_uprobe(inode, offset);
- }
-
- srcu_read_unlock_raw(&uprobes_srcu, current->uprobe_srcu_id);
- current->uprobe_srcu_id = -1;
- up_read(&mm->mmap_sem);
+ uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
if (!uprobe) {
- /* No matching uprobe; signal SIGTRAP. */
- send_sig(SIGTRAP, current, 0);
+ if (is_swbp > 0) {
+ /* No matching uprobe; signal SIGTRAP. */
+ send_sig(SIGTRAP, current, 0);
+ } else {
+ /*
+ * Either we raced with uprobe_unregister() or we can't
+ * access this memory. The latter is only possible if
+ * another thread plays with our ->mm. In both cases
+ * we can simply restart. If this vma was unmapped we
+ * can pretend this insn was not executed yet and get
+ * the (correct) SIGSEGV after restart.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+ }
return;
}
@@ -1620,7 +1617,6 @@ int uprobe_pre_sstep_notifier(struct pt_regs *regs)
utask->state = UTASK_BP_HIT;
set_thread_flag(TIF_UPROBE);
- current->uprobe_srcu_id = srcu_read_lock_raw(&uprobes_srcu);
return 1;
}
@@ -1655,7 +1651,6 @@ static int __init init_uprobes(void)
mutex_init(&uprobes_mutex[i]);
mutex_init(&uprobes_mmap_mutex[i]);
}
- init_srcu_struct(&uprobes_srcu);
return register_die_notifier(&uprobe_exception_nb);
}
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a008663d86c..b4f20fba09f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -312,7 +312,7 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list,
static int __register_ftrace_function(struct ftrace_ops *ops)
{
- if (ftrace_disabled)
+ if (unlikely(ftrace_disabled))
return -ENODEV;
if (FTRACE_WARN_ON(ops == &global_ops))
@@ -4299,16 +4299,12 @@ int register_ftrace_function(struct ftrace_ops *ops)
mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled))
- goto out_unlock;
-
ret = __register_ftrace_function(ops);
if (!ret)
ret = ftrace_startup(ops, 0);
-
- out_unlock:
mutex_unlock(&ftrace_lock);
+
return ret;
}
EXPORT_SYMBOL_GPL(register_ftrace_function);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f765465bffe..49491fa7daa 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3239,6 +3239,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
if (cpu_buffer->commit_page == cpu_buffer->reader_page)
goto out;
+ /* Don't bother swapping if the ring buffer is empty */
+ if (rb_num_of_entries(cpu_buffer) == 0)
+ goto out;
+
/*
* Reset the reader page to size zero.
*/
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a7fa0702be1..a120f98c411 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -830,6 +830,8 @@ int register_tracer(struct tracer *type)
current_trace = saved_tracer;
if (ret) {
printk(KERN_CONT "FAILED!\n");
+ /* Add the warning after printing 'FAILED' */
+ WARN_ON(1);
goto out;
}
/* Only reset on passing, to avoid touching corrupted buffers */
@@ -1708,9 +1710,11 @@ EXPORT_SYMBOL_GPL(trace_vprintk);
static void trace_iterator_increment(struct trace_iterator *iter)
{
+ struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);
+
iter->idx++;
- if (iter->buffer_iter[iter->cpu])
- ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+ if (buf_iter)
+ ring_buffer_read(buf_iter, NULL);
}
static struct trace_entry *
@@ -1718,7 +1722,7 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
unsigned long *lost_events)
{
struct ring_buffer_event *event;
- struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
+ struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);
if (buf_iter)
event = ring_buffer_iter_peek(buf_iter, ts);
@@ -1856,10 +1860,10 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu)
tr->data[cpu]->skipped_entries = 0;
- if (!iter->buffer_iter[cpu])
+ buf_iter = trace_buffer_iter(iter, cpu);
+ if (!buf_iter)
return;
- buf_iter = iter->buffer_iter[cpu];
ring_buffer_iter_reset(buf_iter);
/*
@@ -2205,13 +2209,15 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
int trace_empty(struct trace_iterator *iter)
{
+ struct ring_buffer_iter *buf_iter;
int cpu;
/* If we are looking at one CPU buffer, only check that one */
if (iter->cpu_file != TRACE_PIPE_ALL_CPU) {
cpu = iter->cpu_file;
- if (iter->buffer_iter[cpu]) {
- if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+ buf_iter = trace_buffer_iter(iter, cpu);
+ if (buf_iter) {
+ if (!ring_buffer_iter_empty(buf_iter))
return 0;
} else {
if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
@@ -2221,8 +2227,9 @@ int trace_empty(struct trace_iterator *iter)
}
for_each_tracing_cpu(cpu) {
- if (iter->buffer_iter[cpu]) {
- if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+ buf_iter = trace_buffer_iter(iter, cpu);
+ if (buf_iter) {
+ if (!ring_buffer_iter_empty(buf_iter))
return 0;
} else {
if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
@@ -2381,6 +2388,11 @@ __tracing_open(struct inode *inode, struct file *file)
if (!iter)
return ERR_PTR(-ENOMEM);
+ iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
+ GFP_KERNEL);
+ if (!iter->buffer_iter)
+ goto release;
+
/*
* We make a copy of the current tracer to avoid concurrent
* changes on it while we are reading.
@@ -2441,6 +2453,8 @@ __tracing_open(struct inode *inode, struct file *file)
fail:
mutex_unlock(&trace_types_lock);
kfree(iter->trace);
+ kfree(iter->buffer_iter);
+release:
seq_release_private(inode, file);
return ERR_PTR(-ENOMEM);
}
@@ -2481,6 +2495,7 @@ static int tracing_release(struct inode *inode, struct file *file)
mutex_destroy(&iter->mutex);
free_cpumask_var(iter->started);
kfree(iter->trace);
+ kfree(iter->buffer_iter);
seq_release_private(inode, file);
return 0;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 5aec220d2de..55e1f7f0db1 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -317,6 +317,14 @@ struct tracer {
#define TRACE_PIPE_ALL_CPU -1
+static inline struct ring_buffer_iter *
+trace_buffer_iter(struct trace_iterator *iter, int cpu)
+{
+ if (iter->buffer_iter && iter->buffer_iter[cpu])
+ return iter->buffer_iter[cpu];
+ return NULL;
+}
+
int tracer_init(struct tracer *t, struct trace_array *tr);
int tracing_is_enabled(void);
void trace_wake_up(void);
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index a7d2a4c653d..ce27c8ba8d3 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -538,7 +538,7 @@ get_return_for_leaf(struct trace_iterator *iter,
next = &data->ret;
} else {
- ring_iter = iter->buffer_iter[iter->cpu];
+ ring_iter = trace_buffer_iter(iter, iter->cpu);
/* First peek to compare current entry and the next one */
if (ring_iter)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index df611a0e76c..123b189c732 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1325,4 +1325,4 @@ __init static int init_events(void)
return 0;
}
-device_initcall(init_events);
+early_initcall(init_events);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-15 02:45:52 +0000