1570af302Sopenharmony_ci#define _GNU_SOURCE 2570af302Sopenharmony_ci#include <unistd.h> 3570af302Sopenharmony_ci#include <signal.h> 4570af302Sopenharmony_ci#include "syscall.h" 5570af302Sopenharmony_ci#include "libc.h" 6570af302Sopenharmony_ci 7570af302Sopenharmony_cistruct ctx { 8570af302Sopenharmony_ci size_t count; 9570af302Sopenharmony_ci const gid_t *list; 10570af302Sopenharmony_ci int ret; 11570af302Sopenharmony_ci}; 12570af302Sopenharmony_ci 13570af302Sopenharmony_cistatic void do_setgroups(void *p) 14570af302Sopenharmony_ci{ 15570af302Sopenharmony_ci struct ctx *c = p; 16570af302Sopenharmony_ci if (c->ret<0) return; 17570af302Sopenharmony_ci int ret = __syscall(SYS_setgroups, c->count, c->list); 18570af302Sopenharmony_ci if (ret && !c->ret) { 19570af302Sopenharmony_ci /* If one thread fails to set groups after another has already 20570af302Sopenharmony_ci * succeeded, forcibly killing the process is the only safe 21570af302Sopenharmony_ci * thing to do. State is inconsistent and dangerous. Use 22570af302Sopenharmony_ci * SIGKILL because it is uncatchable. */ 23570af302Sopenharmony_ci __block_all_sigs(0); 24570af302Sopenharmony_ci __syscall(SYS_kill, __syscall(SYS_getpid), SIGKILL); 25570af302Sopenharmony_ci } 26570af302Sopenharmony_ci c->ret = ret; 27570af302Sopenharmony_ci} 28570af302Sopenharmony_ci 29570af302Sopenharmony_ciint setgroups(size_t count, const gid_t list[]) 30570af302Sopenharmony_ci{ 31570af302Sopenharmony_ci /* ret is initially nonzero so that failure of the first thread does not 32570af302Sopenharmony_ci * trigger the safety kill above. */ 33570af302Sopenharmony_ci struct ctx c = { .count = count, .list = list, .ret = 1 }; 34570af302Sopenharmony_ci __synccall(do_setgroups, &c); 35570af302Sopenharmony_ci return __syscall_ret(c.ret); 36570af302Sopenharmony_ci} 37