avoid __synccall for setrlimit on kernels with prlimit syscall

resource limits have been process-wide since linux 2.6.10, and the
prlimit syscall was added in 2.6.36, so prlimit can be assumed to set
the resource limits correctly for the whole process.

diff --git a/src/misc/setrlimit.c b/src/misc/setrlimit.c
index 7a66ab2..8340aee 100644 (file)
--- a/src/misc/setrlimit.c
+++ b/src/misc/setrlimit.c
@@ -6,25 +6,8 @@
 #define MIN(a, b) ((a)<(b) ? (a) : (b))
 #define FIX(x) do{ if ((x)>=SYSCALL_RLIM_INFINITY) (x)=RLIM_INFINITY; }while(0)
 
-static int __setrlimit(int resource, const struct rlimit *rlim)
-{
-       unsigned long k_rlim[2];
-       struct rlimit tmp;
-       if (SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
-               tmp = *rlim;
-               FIX(tmp.rlim_cur);
-               FIX(tmp.rlim_max);
-               rlim = &tmp;
-       }
-       int ret = __syscall(SYS_prlimit64, 0, resource, rlim, 0);
-       if (ret != -ENOSYS) return ret;
-       k_rlim[0] = MIN(rlim->rlim_cur, MIN(-1UL, SYSCALL_RLIM_INFINITY));
-       k_rlim[1] = MIN(rlim->rlim_max, MIN(-1UL, SYSCALL_RLIM_INFINITY));
-       return __syscall(SYS_setrlimit, resource, k_rlim);
-}
-
 struct ctx {
-       const struct rlimit *rlim;
+       unsigned long lim[2];
        int res;
        int err;
 };
@@ -33,12 +16,26 @@ static void do_setrlimit(void *p)
 {
        struct ctx *c = p;
        if (c->err>0) return;
-       c->err = -__setrlimit(c->res, c->rlim);
+       c->err = -__syscall(SYS_setrlimit, c->res, c->lim);
 }
 
 int setrlimit(int resource, const struct rlimit *rlim)
 {
-       struct ctx c = { .res = resource, .rlim = rlim, .err = -1 };
+       struct rlimit tmp;
+       if (SYSCALL_RLIM_INFINITY != RLIM_INFINITY) {
+               tmp = *rlim;
+               FIX(tmp.rlim_cur);
+               FIX(tmp.rlim_max);
+               rlim = &tmp;
+       }
+       int ret = __syscall(SYS_prlimit64, 0, resource, rlim, 0);
+       if (ret != -ENOSYS) return __syscall_ret(ret);
+
+       struct ctx c = {
+               .lim[0] = MIN(rlim->rlim_cur, MIN(-1UL, SYSCALL_RLIM_INFINITY)),
+               .lim[1] = MIN(rlim->rlim_max, MIN(-1UL, SYSCALL_RLIM_INFINITY)),
+               .res = resource, .err = -1
+       };
        __synccall(do_setrlimit, &c);
        if (c.err) {
                if (c.err>0) errno = c.err;