diff options
Diffstat (limited to '')
| -rw-r--r-- | third_party/socket_wrapper/socket_wrapper.c | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/third_party/socket_wrapper/socket_wrapper.c b/third_party/socket_wrapper/socket_wrapper.c index c759d35..37799c8 100644 --- a/third_party/socket_wrapper/socket_wrapper.c +++ b/third_party/socket_wrapper/socket_wrapper.c @@ -1388,6 +1388,9 @@ static ssize_t libc_writev(int fd, const struct iovec *iov, int iovcnt) return swrap.libc.symbols._libc_writev.f(fd, iov, iovcnt); } +/* JEMALLOC: This tells socket_wrapper if it should handle syscall() */ +static bool swrap_handle_syscall; + #ifdef HAVE_SYSCALL DO_NOT_SANITIZE_ADDRESS_ATTRIBUTE static long int libc_vsyscall(long int sysno, va_list va) @@ -1396,7 +1399,27 @@ static long int libc_vsyscall(long int sysno, va_list va) long int rc; int i; - swrap_bind_symbol_all(); + /* + * JEMALLOC: + * + * This is a workaround to prevent a deadlock in jemalloc calling + * malloc_init() twice. The first allocation call will trigger a + * malloc_init() of jemalloc. The functions calls syscall(SYS_open, ...) + * so it goes to socket or uid wrapper. In this code path we need to + * avoid any allocation calls. This will prevent the deadlock. + * + * We also need to avoid dlopen() as that would trigger the recursion + * into malloc_init(), so we use dlsym(RTLD_NEXT), until we reached + * swrap_constructor() or any real socket call at that time + * swrap_bind_symbol_all() will replace the function pointer again after + * dlopen of libc. + */ + if (swrap_handle_syscall) { + swrap_bind_symbol_all(); + } else if (swrap.libc.symbols._libc_syscall.obj == NULL) { + swrap.libc.symbols._libc_syscall.obj = dlsym(RTLD_NEXT, + "syscall"); + } for (i = 0; i < 8; i++) { args[i] = va_arg(va, long int); @@ -1517,6 +1540,8 @@ static void __swrap_bind_symbol_all_once(void) swrap_bind_symbol_rtld_default_optional(uid_wrapper_syscall_valid); swrap_bind_symbol_rtld_default_optional(uid_wrapper_syscall_va); #endif + + swrap_handle_syscall = true; } static void swrap_bind_symbol_all(void) @@ -8745,6 +8770,21 @@ long int syscall(long int sysno, ...) va_start(va, sysno); /* + * JEMALLOC: + * + * This is a workaround to prevent a deadlock in jemalloc calling + * malloc_init() twice. The first allocation call will trigger a + * malloc_init() of jemalloc. The functions calls syscall(SYS_open, ...) + * so it goes to socket or uid wrapper. In this code path we need to + * avoid any allocation calls. This will prevent the deadlock. + */ + if (!swrap_handle_syscall) { + rc = libc_vsyscall(sysno, va); + va_end(va); + return rc; + } + + /* * We should only handle the syscall numbers * we care about... */ @@ -8860,6 +8900,9 @@ void swrap_constructor(void) pthread_atfork(&swrap_thread_prepare, &swrap_thread_parent, &swrap_thread_child); + + /* Let socket_wrapper handle syscall() */ + swrap_handle_syscall = true; } /**************************** |