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 @@ +From 94225ab4bcc1613531558a632270b5edce779bc9 Mon Sep 17 00:00:00 2001 +From: Khem Raj <raj.khem@gmail.com> +Date: Sat, 27 Jan 2018 10:08:04 -0800 +Subject: [PATCH 27/27] Acquire ld.so lock before switching to malloc_atfork + +The patch is from + https://sourceware.org/bugzilla/show_bug.cgi?id=4578 + +If a thread happens to hold dl_load_lock and have r_state set to RT_ADD or +RT_DELETE at the time another thread calls fork(), then the child exit code +from fork (in nptl/sysdeps/unix/sysv/linux/fork.c in our case) re-initializes +dl_load_lock but does not restore r_state to RT_CONSISTENT. If the child +subsequently requires ld.so functionality before calling exec(), then the +assertion will fire. + +The patch acquires dl_load_lock on entry to fork() and releases it on exit +from the parent path. The child path is initialized as currently done. +This is essentially pthreads_atfork, but forced to be first because the +acquisition of dl_load_lock must happen before malloc_atfork is active +to avoid a deadlock. + +The patch has not yet been integrated upstream. + +Upstream-Status: Pending [ Not Author See bugzilla] + +Signed-off-by: Raghunath Lolur <Raghunath.Lolur@kpit.com> +Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com> +Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com> +Signed-off-by: Khem Raj <raj.khem@gmail.com> +--- + sysdeps/nptl/fork.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +diff --git a/sysdeps/nptl/fork.c b/sysdeps/nptl/fork.c +index f87506f398..225e7b51f8 100644 +--- a/sysdeps/nptl/fork.c ++++ b/sysdeps/nptl/fork.c +@@ -25,6 +25,7 @@ + #include <tls.h> + #include <hp-timing.h> + #include <ldsodefs.h> ++#include <libc-lock.h> + #include <stdio-lock.h> + #include <atomic.h> + #include <nptl/pthreadP.h> +@@ -60,6 +61,10 @@ __libc_fork (void) + but our current fork implementation is not. */ + bool multiple_threads = THREAD_GETMEM (THREAD_SELF, header.multiple_threads); + ++ /* grab ld.so lock BEFORE switching to malloc_atfork */ ++ __rtld_lock_lock_recursive (GL(dl_load_lock)); ++ __rtld_lock_lock_recursive (GL(dl_load_write_lock)); ++ + /* Run all the registered preparation handlers. In reverse order. + While doing this we build up a list of all the entries. */ + struct fork_handler *runp; +@@ -246,6 +251,10 @@ __libc_fork (void) + + allp = allp->next; + } ++ ++ /* unlock ld.so last, because we locked it first */ ++ __rtld_lock_unlock_recursive (GL(dl_load_write_lock)); ++ __rtld_lock_unlock_recursive (GL(dl_load_lock)); + } + + return pid; +-- +2.16.1 + |