diff options
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/musl/patch/0001-avoid-set-id-setrlimit-misbehavior-and-hang-in-vfork.patch | 49 | ||||
| -rw-r--r-- | pkg/musl/ver | 2 |
2 files changed, 50 insertions, 1 deletions
diff --git a/pkg/musl/patch/0001-avoid-set-id-setrlimit-misbehavior-and-hang-in-vfork.patch b/pkg/musl/patch/0001-avoid-set-id-setrlimit-misbehavior-and-hang-in-vfork.patch new file mode 100644 index 00000000..f8e80031 --- /dev/null +++ b/pkg/musl/patch/0001-avoid-set-id-setrlimit-misbehavior-and-hang-in-vfork.patch @@ -0,0 +1,49 @@ +From 1fce9805c251a187b75bd527cad0b1e1021c296b Mon Sep 17 00:00:00 2001 +From: Rich Felker <dalias@aerifal.cx> +Date: Thu, 17 Sep 2020 15:09:46 -0400 +Subject: [PATCH] avoid set*id/setrlimit misbehavior and hang in vforked/cloned + child + +taking the deprecated/dropped vfork spec strictly, doing pretty much +anything but execve in the child is wrong and undefined. however, +these are commonly needed operations to setup the child state before +exec, and historical implementations tolerated them. + +for single-threaded parents, these operations already worked as +expected in the vforked child. however, due to the need for __synccall +to synchronize id/resource limit changes among all threads, calling +these functions in the vforked child of a multithreaded parent caused +a misdirected broadcast signaling of all threads in the parent. these +signals could kill the parent entirely if the synccall signal handler +had never been installed in the parent, or could be ignored if it had, +or could signal/kill one or more utterly wrong processes if the parent +already terminated (due to vfork semantics, only possible via fatal +signal) and the parent tids were recycled. in any case, the expected +number of semaphore posts would never happen, so the child would +permanently hang (with all signals blocked) waiting for them. + +to mitigate this, and also make the normal usage case work as +intended, treat the condition where the caller's actual tid does not +match the tid in its thread structure as single-threaded, and bypass +the entire synccall broadcast operation. +--- + src/thread/synccall.c | 3 ++- + 1 file changed, 2 insertions(+), 1 deletion(-) + +diff --git a/src/thread/synccall.c b/src/thread/synccall.c +index 648a6ad4..d58c851f 100644 +--- a/src/thread/synccall.c ++++ b/src/thread/synccall.c +@@ -63,7 +63,8 @@ void __synccall(void (*func)(void *), void *ctx) + sem_init(&target_sem, 0, 0); + sem_init(&caller_sem, 0, 0); + +- if (!libc.threads_minus_1) goto single_threaded; ++ if (!libc.threads_minus_1 || __syscall(SYS_gettid) != self->tid) ++ goto single_threaded; + + callback = func; + context = ctx; +-- +2.28.0 + diff --git a/pkg/musl/ver b/pkg/musl/ver index 97fe035b..608f1b9b 100644 --- a/pkg/musl/ver +++ b/pkg/musl/ver @@ -1 +1 @@ -1.2.1 r0 +1.2.1 r1 |