From: Yang Shi <yang.shi@linux.alibaba.com>
To: mhocko@kernel.org, willy@infradead.org,
ldufour@linux.vnet.ibm.com, kirill@shutemov.name, vbabka@suse.cz,
akpm@linux-foundation.org, peterz@infradead.org,
mingo@redhat.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org
Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [RFC v8 PATCH 2/5] uprobes: introduce has_uprobes helper
Date: Thu, 16 Aug 2018 02:49:47 +0800 [thread overview]
Message-ID: <1534358990-85530-3-git-send-email-yang.shi@linux.alibaba.com> (raw)
In-Reply-To: <1534358990-85530-1-git-send-email-yang.shi@linux.alibaba.com>
We need check if mm or vma has uprobes in the following patch to check
if a vma could be unmapped with holding read mmap_sem. The checks and
pre-conditions used by uprobe_munmap() look just suitable for this
purpose.
Extracting those checks into a helper function, has_uprobes().
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
---
include/linux/uprobes.h | 7 +++++++
kernel/events/uprobes.c | 23 ++++++++++++++++-------
2 files changed, 23 insertions(+), 7 deletions(-)
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 0a294e9..418764e 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -149,6 +149,8 @@ struct uprobes_state {
extern bool arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs);
extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
void *src, unsigned long len);
+extern bool has_uprobes(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end);
#else /* !CONFIG_UPROBES */
struct uprobes_state {
};
@@ -203,5 +205,10 @@ static inline void uprobe_copy_process(struct task_struct *t, unsigned long flag
static inline void uprobe_clear_state(struct mm_struct *mm)
{
}
+static inline bool has_uprobes(struct vm_area_struct *vma, unsigned long start,
+ unsgined long end)
+{
+ return false;
+}
#endif /* !CONFIG_UPROBES */
#endif /* _LINUX_UPROBES_H */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index aed1ba5..568481c 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1114,22 +1114,31 @@ int uprobe_mmap(struct vm_area_struct *vma)
return !!n;
}
-/*
- * Called in context of a munmap of a vma.
- */
-void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+bool
+has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
if (no_uprobe_events() || !valid_vma(vma, false))
- return;
+ return false;
if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
- return;
+ return false;
if (!test_bit(MMF_HAS_UPROBES, &vma->vm_mm->flags) ||
test_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags))
- return;
+ return false;
if (vma_has_uprobes(vma, start, end))
+ return true;
+
+ return false;
+}
+
+/*
+ * Called in context of a munmap of a vma.
+ */
+void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+ if (has_uprobes(vma, start, end))
set_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags);
}
--
1.8.3.1
next prev parent reply other threads:[~2018-08-15 18:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-15 18:49 [RFC v8 PATCH 0/5] mm: zap pages with read mmap_sem in munmap for large mapping Yang Shi
2018-08-15 18:49 ` [RFC v8 PATCH 1/5] mm: refactor do_munmap() to extract the common part Yang Shi
2018-08-15 18:49 ` Yang Shi [this message]
2018-08-22 10:55 ` [RFC v8 PATCH 2/5] uprobes: introduce has_uprobes helper Vlastimil Babka
2018-08-22 15:07 ` Srikar Dronamraju
2018-08-22 20:51 ` Yang Shi
2018-08-23 15:15 ` Oleg Nesterov
2018-08-23 16:07 ` Yang Shi
2018-08-15 18:49 ` [RFC v8 PATCH 3/5] mm: mmap: zap pages with read mmap_sem in munmap Yang Shi
2018-08-15 19:16 ` Matthew Wilcox
2018-08-15 21:09 ` Matthew Wilcox
2018-08-15 21:54 ` Yang Shi
2018-08-16 2:46 ` Matthew Wilcox
2018-08-16 6:11 ` Yang Shi
2018-08-22 11:11 ` Vlastimil Babka
2018-08-22 19:20 ` Yang Shi
2018-08-22 11:19 ` Vlastimil Babka
2018-08-22 20:45 ` Yang Shi
2018-08-22 21:10 ` Kirill A. Shutemov
2018-08-22 21:42 ` Dave Hansen
2018-08-22 21:56 ` Yang Shi
2018-08-22 22:03 ` Dave Hansen
2018-08-15 18:49 ` [RFC v8 PATCH 4/5] mm: unmap VM_HUGETLB mappings with optimized path Yang Shi
2018-08-15 18:49 ` [RFC v8 PATCH 5/5] mm: unmap VM_PFNMAP " Yang Shi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1534358990-85530-3-git-send-email-yang.shi@linux.alibaba.com \
--to=yang.shi@linux.alibaba.com \
--cc=acme@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=jolsa@redhat.com \
--cc=kirill@shutemov.name \
--cc=ldufour@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=vbabka@suse.cz \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).