diff options
Diffstat (limited to 'nptl/allocatestack.c')
| -rw-r--r-- | nptl/allocatestack.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 9095ef4..d95ffe9 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -1059,6 +1059,25 @@ setxid_signal_thread (struct xid_command *cmdp, struct pthread *t) return 0; } +/* Check for consistency across set*id system call results. The abort + should not happen as long as all privileges changes happen through + the glibc wrappers. ERROR must be 0 (no error) or an errno + code. */ +void +attribute_hidden +__nptl_setxid_error (struct xid_command *cmdp, int error) +{ + do + { + int olderror = cmdp->error; + if (olderror == error) + break; + if (olderror != -1) + /* Mismatch between current and previous results. */ + abort (); + } + while (atomic_compare_and_exchange_bool_acq (&cmdp->error, error, -1)); +} int attribute_hidden @@ -1070,6 +1089,7 @@ __nptl_setxid (struct xid_command *cmdp) __xidcmd = cmdp; cmdp->cntr = 0; + cmdp->error = -1; struct pthread *self = THREAD_SELF; @@ -1153,11 +1173,14 @@ __nptl_setxid (struct xid_command *cmdp) INTERNAL_SYSCALL_DECL (err); result = INTERNAL_SYSCALL_NCS (cmdp->syscall_no, err, 3, cmdp->id[0], cmdp->id[1], cmdp->id[2]); - if (INTERNAL_SYSCALL_ERROR_P (result, err)) + int error = 0; + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err))) { - __set_errno (INTERNAL_SYSCALL_ERRNO (result, err)); + error = INTERNAL_SYSCALL_ERRNO (result, err); + __set_errno (error); result = -1; } + __nptl_setxid_error (cmdp, error); lll_unlock (stack_cache_lock, LLL_PRIVATE); return result; |