diff options
Diffstat (limited to 'meta/recipes-core/glibc/glibc/0027-Acquire-ld.so-lock-before-switching-to-malloc_atfork.patch')
-rw-r--r-- | meta/recipes-core/glibc/glibc/0027-Acquire-ld.so-lock-before-switching-to-malloc_atfork.patch | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/meta/recipes-core/glibc/glibc/0027-Acquire-ld.so-lock-before-switching-to-malloc_atfork.patch b/meta/recipes-core/glibc/glibc/0027-Acquire-ld.so-lock-before-switching-to-malloc_atfork.patch new file mode 100644 index 0000000000..9ec234bd51 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0027-Acquire-ld.so-lock-before-switching-to-malloc_atfork.patch | |||
@@ -0,0 +1,70 @@ | |||
1 | From 94225ab4bcc1613531558a632270b5edce779bc9 Mon Sep 17 00:00:00 2001 | ||
2 | From: Khem Raj <raj.khem@gmail.com> | ||
3 | Date: Sat, 27 Jan 2018 10:08:04 -0800 | ||
4 | Subject: [PATCH 27/27] Acquire ld.so lock before switching to malloc_atfork | ||
5 | |||
6 | The patch is from | ||
7 | https://sourceware.org/bugzilla/show_bug.cgi?id=4578 | ||
8 | |||
9 | If a thread happens to hold dl_load_lock and have r_state set to RT_ADD or | ||
10 | RT_DELETE at the time another thread calls fork(), then the child exit code | ||
11 | from fork (in nptl/sysdeps/unix/sysv/linux/fork.c in our case) re-initializes | ||
12 | dl_load_lock but does not restore r_state to RT_CONSISTENT. If the child | ||
13 | subsequently requires ld.so functionality before calling exec(), then the | ||
14 | assertion will fire. | ||
15 | |||
16 | The patch acquires dl_load_lock on entry to fork() and releases it on exit | ||
17 | from the parent path. The child path is initialized as currently done. | ||
18 | This is essentially pthreads_atfork, but forced to be first because the | ||
19 | acquisition of dl_load_lock must happen before malloc_atfork is active | ||
20 | to avoid a deadlock. | ||
21 | |||
22 | The patch has not yet been integrated upstream. | ||
23 | |||
24 | Upstream-Status: Pending [ Not Author See bugzilla] | ||
25 | |||
26 | Signed-off-by: Raghunath Lolur <Raghunath.Lolur@kpit.com> | ||
27 | Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com> | ||
28 | Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com> | ||
29 | Signed-off-by: Khem Raj <raj.khem@gmail.com> | ||
30 | --- | ||
31 | sysdeps/nptl/fork.c | 9 +++++++++ | ||
32 | 1 file changed, 9 insertions(+) | ||
33 | |||
34 | diff --git a/sysdeps/nptl/fork.c b/sysdeps/nptl/fork.c | ||
35 | index f87506f398..225e7b51f8 100644 | ||
36 | --- a/sysdeps/nptl/fork.c | ||
37 | +++ b/sysdeps/nptl/fork.c | ||
38 | @@ -25,6 +25,7 @@ | ||
39 | #include <tls.h> | ||
40 | #include <hp-timing.h> | ||
41 | #include <ldsodefs.h> | ||
42 | +#include <libc-lock.h> | ||
43 | #include <stdio-lock.h> | ||
44 | #include <atomic.h> | ||
45 | #include <nptl/pthreadP.h> | ||
46 | @@ -60,6 +61,10 @@ __libc_fork (void) | ||
47 | but our current fork implementation is not. */ | ||
48 | bool multiple_threads = THREAD_GETMEM (THREAD_SELF, header.multiple_threads); | ||
49 | |||
50 | + /* grab ld.so lock BEFORE switching to malloc_atfork */ | ||
51 | + __rtld_lock_lock_recursive (GL(dl_load_lock)); | ||
52 | + __rtld_lock_lock_recursive (GL(dl_load_write_lock)); | ||
53 | + | ||
54 | /* Run all the registered preparation handlers. In reverse order. | ||
55 | While doing this we build up a list of all the entries. */ | ||
56 | struct fork_handler *runp; | ||
57 | @@ -246,6 +251,10 @@ __libc_fork (void) | ||
58 | |||
59 | allp = allp->next; | ||
60 | } | ||
61 | + | ||
62 | + /* unlock ld.so last, because we locked it first */ | ||
63 | + __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); | ||
64 | + __rtld_lock_unlock_recursive (GL(dl_load_lock)); | ||
65 | } | ||
66 | |||
67 | return pid; | ||
68 | -- | ||
69 | 2.16.1 | ||
70 | |||