diff options
Diffstat (limited to 'usr/src/lib/libidmap/common/idmap_api.c')
| -rw-r--r-- | usr/src/lib/libidmap/common/idmap_api.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/usr/src/lib/libidmap/common/idmap_api.c b/usr/src/lib/libidmap/common/idmap_api.c index 06a849f902..09b26bb26c 100644 --- a/usr/src/lib/libidmap/common/idmap_api.c +++ b/usr/src/lib/libidmap/common/idmap_api.c @@ -39,6 +39,7 @@ #include <sys/stat.h> #include <dlfcn.h> #include <libintl.h> +#include <ucontext.h> #include "idmap_impl.h" static struct timeval TIMEOUT = { 25, 0 }; @@ -103,6 +104,8 @@ idmap_free(void *ptr) { } +#define MIN_STACK_NEEDS 16384 + /* * Create and Initialize idmap client handle for rpc/doors * @@ -113,13 +116,45 @@ idmap_stat idmap_init(idmap_handle_t **handle) { CLIENT *clnt = NULL; struct idmap_handle *hptr; + uint_t sendsz = 0; + stack_t st; *handle = NULL; hptr = (struct idmap_handle *)calloc(1, sizeof (*hptr)); if (hptr == NULL) return (IDMAP_ERR_MEMORY); - clnt = clnt_door_create(IDMAP_PROG, IDMAP_V1, 0); + /* + * clnt_door_call() alloca()s sendsz bytes (twice too, once for + * the call args buffer and once for the call result buffer), so + * we want to pick a sendsz that will be large enough, but not + * too large. + */ + if (stack_getbounds(&st) == 0) { + /* + * Estimate how much stack space is left; + * st.ss_sp is the top of stack. + */ + if ((char *)&sendsz < (char *)st.ss_sp) + /* stack grows up */ + sendsz = ((char *)st.ss_sp - (char *)&sendsz); + else + /* stack grows down */ + sendsz = ((char *)&sendsz - (char *)st.ss_sp); + + /* + * Take much of the stack space left, divided by two, + * but leave enough for our needs (just a guess!), and + * if we can't, then roll the dice. + */ + sendsz = RNDUP(sendsz / 2); + if (sendsz < MIN_STACK_NEEDS) + sendsz = 0; /* RPC call may fail */ + else if (sendsz > IDMAP_MAX_DOOR_RPC) + sendsz = IDMAP_MAX_DOOR_RPC; + } + + clnt = clnt_door_create(IDMAP_PROG, IDMAP_V1, sendsz); if (clnt == NULL) { free(hptr); return (IDMAP_ERR_RPC); |