From: Anthony Yznaga <anthony.yznaga@oracle.com>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-arch@vger.kernel.org
Cc: mhocko@kernel.org, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, x86@kernel.org, hpa@zytor.com,
viro@zeniv.linux.org.uk, akpm@linux-foundation.org,
arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org,
gerg@linux-m68k.org, ktkhai@virtuozzo.com,
christian.brauner@ubuntu.com, peterz@infradead.org,
esyr@redhat.com, jgg@ziepe.ca, christian@kellner.me,
areber@redhat.com, cyphar@cyphar.com, steven.sistare@oracle.com
Subject: [RFC PATCH 5/5] mm: introduce MADV_DOEXEC
Date: Mon, 27 Jul 2020 10:11:27 -0700 [thread overview]
Message-ID: <1595869887-23307-6-git-send-email-anthony.yznaga@oracle.com> (raw)
In-Reply-To: <1595869887-23307-1-git-send-email-anthony.yznaga@oracle.com>
madvise MADV_DOEXEC preserves a memory range across exec. Initially
only supported for non-executable, non-stack, anonymous memory.
MADV_DONTEXEC reverts the effect of a previous MADV_DOXEXEC call and
undoes the preservation of the range. After a successful exec call,
the behavior of all ranges reverts to MADV_DONTEXEC.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com>
---
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 f94f65d429be..7c5f616b28f7 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -72,6 +72,9 @@
#define MADV_COLD 20 /* deactivate these pages */
#define MADV_PAGEOUT 21 /* reclaim these pages */
+#define MADV_DOEXEC 22 /* do inherit across exec */
+#define MADV_DONTEXEC 23 /* don't inherit across exec */
+
/* compatibility flags */
#define MAP_FILE 0
diff --git a/mm/madvise.c b/mm/madvise.c
index dd1d43cf026d..b447fa748649 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -103,6 +103,26 @@ static long madvise_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->vm_file || 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;
@@ -983,6 +1003,8 @@ static int madvise_inject_error(int behavior,
case MADV_SOFT_OFFLINE:
case MADV_HWPOISON:
#endif
+ case MADV_DOEXEC:
+ case MADV_DONTEXEC:
return true;
default:
@@ -1037,6 +1059,9 @@ static int madvise_inject_error(int behavior,
* MADV_DONTDUMP - the application wants to prevent pages in the given range
* from being included in its core dump.
* MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump.
+ * 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
--
1.8.3.1
next prev parent reply other threads:[~2020-07-27 17:08 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 17:11 [RFC PATCH 0/5] madvise MADV_DOEXEC Anthony Yznaga
2020-07-27 17:07 ` Eric W. Biederman
2020-07-27 18:00 ` Steven Sistare
2020-07-28 13:40 ` Christian Brauner
2020-07-27 17:11 ` [RFC PATCH 1/5] elf: reintroduce using MAP_FIXED_NOREPLACE for elf executable mappings Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 2/5] mm: do not assume only the stack vma exists in setup_arg_pages() Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 3/5] mm: introduce VM_EXEC_KEEP Anthony Yznaga
2020-07-28 13:38 ` Eric W. Biederman
2020-07-28 17:44 ` Anthony Yznaga
2020-07-29 13:52 ` Kirill A. Shutemov
2020-07-29 23:20 ` Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 4/5] exec, elf: require opt-in for accepting preserved mem Anthony Yznaga
2020-07-27 17:11 ` Anthony Yznaga [this message]
2020-07-28 13:22 ` [RFC PATCH 5/5] mm: introduce MADV_DOEXEC Kirill Tkhai
2020-07-28 14:06 ` Steven Sistare
2020-07-28 11:34 ` [RFC PATCH 0/5] madvise MADV_DOEXEC Kirill Tkhai
2020-07-28 17:28 ` Anthony Yznaga
2020-07-28 14:23 ` Andy Lutomirski
2020-07-28 14:30 ` Steven Sistare
2020-07-30 15:22 ` Matthew Wilcox
2020-07-30 15:27 ` Christian Brauner
2020-07-30 15:34 ` Matthew Wilcox
2020-07-30 15:54 ` Christian Brauner
2020-07-31 9:12 ` Stefan Hajnoczi
2020-07-30 15:59 ` Steven Sistare
2020-07-30 17:12 ` Matthew Wilcox
2020-07-30 17:35 ` Steven Sistare
2020-07-30 17:49 ` Matthew Wilcox
2020-07-30 18:27 ` Steven Sistare
2020-07-30 21:58 ` Eric W. Biederman
2020-07-31 14:57 ` Steven Sistare
2020-07-31 15:27 ` Matthew Wilcox
2020-07-31 16:11 ` Steven Sistare
2020-07-31 16:56 ` Jason Gunthorpe
2020-07-31 17:15 ` Steven Sistare
2020-07-31 17:48 ` Jason Gunthorpe
2020-07-31 17:55 ` Steven Sistare
2020-08-03 8:32 ` David Laight
2020-07-31 17:23 ` Matthew Wilcox
2020-08-03 15:28 ` Eric W. Biederman
2020-08-03 15:42 ` James Bottomley
2020-08-03 20:03 ` Steven Sistare
2020-08-04 8:44 ` David Laight
2020-08-04 11:13 ` Matthew Wilcox
2020-08-03 19:29 ` Steven Sistare
2020-07-31 19:41 ` Steven Sistare
2021-07-08 9:52 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2021-07-08 12:48 ` Steven Sistare
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