From c94a9cb3408d0fb2bec28be7cc966ece0c24e61f Mon Sep 17 00:00:00 2001 From: "Frank Ch. Eigler" Date: Wed, 3 Dec 2008 16:56:03 -0500 Subject: [PATCH] PR6925: tolerate modules left over from previous crashed? stap sessions --- runtime/staprun/ChangeLog | 6 ++++++ runtime/staprun/staprun.c | 14 ++++++++++++-- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/runtime/staprun/ChangeLog b/runtime/staprun/ChangeLog index 35dd77196..aff94da3a 100644 --- a/runtime/staprun/ChangeLog +++ b/runtime/staprun/ChangeLog @@ -1,3 +1,9 @@ +2008-12-03 Frank Ch. Eigler + + PR6925 + * staprun (init_staprun): If a stap_* module load fails, try + to unload possible leftover, and try again. + 2008-11-28 Frank Ch. Eigler PR4783 diff --git a/runtime/staprun/staprun.c b/runtime/staprun/staprun.c index b6d779793..9d647675c 100644 --- a/runtime/staprun/staprun.c +++ b/runtime/staprun/staprun.c @@ -136,6 +136,7 @@ static int enable_uprobes(void) static int insert_stap_module(void) { char bufsize_option[128]; + if (snprintf_chk(bufsize_option, 128, "_stp_bufsize=%d", buffer_size)) return -1; return insert_module(modpath, bufsize_option, modoptions); @@ -209,8 +210,17 @@ int init_staprun(void) else if (!attach_mod) { if (need_uprobes && enable_uprobes() != 0) return -1; - if (insert_stap_module() < 0) - return -1; + if (insert_stap_module() < 0) { + /* staprun or stapio might have crashed or been SIGKILL'd, + without first removing the kernel module. This would block + a subsequent rerun attempt. So here we gingerly try to + unload it first. */ + int ret = delete_module (modname, O_NONBLOCK); + err("Retrying, after attempted removal of module %s (rc %d)\n", modname, ret); + /* Then we try an insert a second time. */ + if (insert_stap_module() < 0) + return -1; + } if (send_relocations() < 0) return -1; } -- 2.43.5