The commit is pushed to "branch-rh9-5.14.0-427.44.1.vz9.80.x-ovz" and will
appear at g...@bitbucket.org:openvz/vzkernel.git
after rh9-5.14.0-427.44.1.vz9.80.5
------>
commit 8d21192ba4fba88cf663c202721fd2c1db4e9d74
Author: Steve Sistare <steven.sist...@oracle.com>
Date: Tue Oct 27 16:47:57 2020 -0700
oracle/mm: introduce MADV_DOEXEC
madvise MADV_DOEXEC preserves a memory range across exec. Initially
only supported for non-executable, non-stack, anonymous memory.
MADV_DOEXEC is single-use and after exec madvise must done again to
preserve memory for a subsequent exec.
MADV_DONTEXEC reverts the effect of a previous MADV_DOXEXEC call and
undoes the preservation of the range.
Orabug: 32387875
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
Signed-off-by: Anthony Yznaga <anthony.yzn...@oracle.com>
Reviewed-by: Liam R. Howlett <liam.howl...@oracle.com>
https://virtuozzo.atlassian.net/browse/VSTOR-96305
(cherry picked from Oracle commit 4693c5d9d799eb4803c5afc781cc60e2b645e398)
Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com>
+++
commit 606472268c9ca1edb06b3f0e17477a6b8f229c29
Author: Anthony Yznaga <anthony.yzn...@oracle.com>
Date: Thu Feb 22 15:11:46 2024 -0800
mm: avoid conflict between MADV_DOEXEC and upstream advice values
Change MADV_DOEXEC and MADV_DONTEXEC to values that does not conflict
with new advice values added upstream which can hinder the ability of
a cross-distro application from determining if a conflicting advice
value is supported. As provided in the original patchset, a consumer
of MADV_DOEXEC is expected to read /proc/sys/vm/madv_doexec_flag to
determine the correct value to use.
If an application is affected by the conflict, one possible workaround
is to test for and read /proc/sys/vm/madv_doexec_flag.
Orabug: 36334308
Signed-off-by: Anthony Yznaga <anthony.yzn...@oracle.com>
Reviewed-by: Jane Chu <jane....@oracle.com>
Signed-off-by: Brian Maly <brian.m...@oracle.com>
Feature: oracle/mm: MADV_DOEXEC madvise() flag
---
include/uapi/asm-generic/mman-common.h | 3 +++
mm/madvise.c | 25 +++++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/include/uapi/asm-generic/mman-common.h
b/include/uapi/asm-generic/mman-common.h
index 6ce1f1ceb432..7a98ab73fe88 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -79,6 +79,9 @@
#define MADV_COLLAPSE 25 /* Synchronous hugepage collapse */
+#define MADV_DOEXEC 201 /* do inherit across exec */
+#define MADV_DONTEXEC 202 /* don't inherit across exec */
+
/* compatibility flags */
#define MAP_FILE 0
diff --git a/mm/madvise.c b/mm/madvise.c
index 0583abc9ca19..8cab55109411 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1083,6 +1083,26 @@ static int madvise_vma_behavior(struct vm_area_struct
*vma,
case MADV_KEEPONFORK:
new_flags &= ~VM_WIPEONFORK;
break;
+ case MADV_DOEXEC:
+ /*
+ * MADV_DOEXEC is only supported on private, non-executable,
+ * non-stack anonymous memory and if the VM_EXEC_KEEP flag
+ * is available.
+ */
+ if (!VM_EXEC_KEEP || !vma_is_anonymous(vma) || vma->vm_flags &
(VM_EXEC|VM_SHARED|VM_STACK)) {
+ error = -EINVAL;
+ goto out;
+ }
+ new_flags |= (new_flags & ~VM_MAYEXEC) | VM_EXEC_KEEP;
+ break;
+ case MADV_DONTEXEC:
+ if (!VM_EXEC_KEEP) {
+ error = -EINVAL;
+ goto out;
+ }
+ if (new_flags & VM_EXEC_KEEP)
+ new_flags |= (new_flags & ~VM_EXEC_KEEP) | VM_MAYEXEC;
+ break;
case MADV_DONTDUMP:
new_flags |= VM_DONTDUMP;
break;
@@ -1208,6 +1228,8 @@ madvise_behavior_valid(int behavior)
case MADV_SOFT_OFFLINE:
case MADV_HWPOISON:
#endif
+ case MADV_DOEXEC:
+ case MADV_DONTEXEC:
return true;
default:
@@ -1401,6 +1423,9 @@ int madvise_set_anon_name(struct mm_struct *mm, unsigned
long start,
* triggering read faults if required
* MADV_POPULATE_WRITE - populate (prefault) page tables writable by
* triggering write faults if required
+ * MADV_DOEXEC - On exec, preserve and duplicate this area in the new process
+ * if the new process allows it.
+ * MADV_DONTEXEC - Undo the effect of MADV_DOEXEC.
*
* return values:
* zero - success
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