From 4a3ad35328520f2d2f835397ba743b1f39fb4b79 Mon Sep 17 00:00:00 2001 From: Junlong Li Date: Thu, 27 May 2021 10:31:20 -0400 Subject: [PATCH] Extend vma mapped entries when the address is adjacent. When two segments are adjacent, extend the first to contain the second instead of adding another entry. --- runtime/task_finder_vma.c | 6 +++--- runtime/vma.c | 15 ++++++++------- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/runtime/task_finder_vma.c b/runtime/task_finder_vma.c index 17aaec386..fc388aaf2 100644 --- a/runtime/task_finder_vma.c +++ b/runtime/task_finder_vma.c @@ -54,7 +54,7 @@ struct __stp_tf_vma_entry { struct task_struct *tsk; unsigned long vm_start; unsigned long vm_end; - unsigned long offset; + unsigned long offset; //offset from base addr of the module char path[TASK_FINDER_VMA_ENTRY_PATHLEN]; /* mmpath name, if known */ // User data (possibly stp_module) @@ -243,7 +243,7 @@ stap_add_vma_map_info(struct task_struct *tsk, unsigned long vm_start, } stp_spin_lock_irqsave(&bucket->lock, flags); - hlist_add_head_rcu(&entry->hlist, &bucket->head); + hlist_add_tail_rcu(&entry->hlist, &bucket->head); stp_spin_unlock_irqrestore(&bucket->lock, flags); return 0; } @@ -303,7 +303,7 @@ stap_find_vma_map_info(struct task_struct *tsk, unsigned long addr, bucket = __stp_tf_get_vma_bucket(tsk); entry = __stp_tf_get_vma_map(bucket, tsk, 1, addr >= entry->vm_start && - addr < entry->vm_end); + addr <= entry->vm_end); if (!entry) return -ESRCH; diff --git a/runtime/vma.c b/runtime/vma.c index 2bf1b0a9c..78623fda3 100644 --- a/runtime/vma.c +++ b/runtime/vma.c @@ -185,14 +185,15 @@ static int _stp_vma_mmap_cb(struct stap_task_finder_target *tgt, module, &vm_start, &vm_end, NULL); - if (res == -ESRCH || vm_start + offset == addr) + if (res == -ESRCH) res = stap_add_vma_map_info(tsk->group_leader, - addr, addr + length, - offset, path, module); - else if (res == 0 && vm_end + 1 == addr) - res = stap_extend_vma_map_info(tsk->group_leader, - vm_start, - addr + length); + addr, addr + length, + 0, path, module); + else + res = stap_add_vma_map_info(tsk->group_leader, + addr, addr + length, + addr - vm_start, path, module); + /* VMA entries are allocated dynamically, this is fine, * since we are in a task_finder callback, which is in * user context. */ -- 2.43.5