/* stapkp_refresh is called for two reasons: either a kprobe needs to be
* enabled/disabled (modname is NULL), or a module has been loaded/unloaded and
* kprobes need to be registered/unregistered (modname is !NULL). */
static void
stapkp_refresh(const char *modname,
struct stap_dwarf_probe *probes,
size_t nprobes)
{
size_t i;
for (i = 0; i < nprobes; i++) {
struct stap_dwarf_probe *sdp = &probes[i];
// was this probe's target module loaded/unloaded
if (modname && sdp->module
&& strcmp(modname, sdp->module) == 0) {
int rc;
unsigned long addr = stapkp_relocate_addr(sdp);
// module being loaded?
if (sdp->registered_p == 0 && addr != 0)
stapkp_register_probe(sdp);
// module/section being unloaded?
else if (sdp->registered_p == 1 && addr == 0)
stapkp_unregister_probe(sdp);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
} else if (stapkp_should_enable_probe(sdp)
|| stapkp_should_disable_probe(sdp)) {
stapkp_refresh_probe(sdp);
#endif
}
}
}
static void
stapkp_unregister_probes(struct stap_dwarf_probe *probes,
size_t nprobes)
{
#if defined(STAPCONF_UNREGISTER_KPROBES)
// Unregister using batch mode
stapkp_batch_unregister_probes(probes, nprobes);
#else
// We'll have to unregister them one by one
size_t i;
for (i = 0; i < nprobes; i++) {
struct stap_dwarf_probe *sdp = &probes[i];
if (!sdp->registered_p)
continue;
stapkp_unregister_probe(sdp);
}
#endif
}
static int
stapkp_disable_probe(struct stap_dwarf_probe *sdp)
{
int ret = 0;
dbug_otf("disabling (k%sprobe) pidx %zu\n",
sdp->return_p ? "ret" : "", sdp->probe->index);
ret = sdp->return_p ? disable_kretprobe(&sdp->kprobe->u.krp)
: disable_kprobe(&sdp->kprobe->u.kp);
if (ret != 0) {
stapkp_unregister_probe(sdp);
dbug_otf("failed to disable (k%sprobe) pidx %zu (rc %d)\n",
sdp->return_p ? "ret" : "", sdp->probe->index, ret);
}
return ret;
}
static int
stapkp_enable_probe(struct stap_kprobe_probe *skp)
{
int ret = 0;
dbug_otf("enabling (k%sprobe) pidx %zu\n",
skp->return_p ? "ret" : "", skp->probe->index);
ret = skp->return_p ? enable_kretprobe(&skp->kprobe->u.krp)
: enable_kprobe(&skp->kprobe->u.kp);
if (ret != 0) {
stapkp_unregister_probe(skp);
dbug_otf("failed to enable (k%sprobe) pidx %zu (rc %d)\n",
skp->return_p ? "ret" : "", skp->probe->index, ret);
}
return ret;
}
/* stapkp_refresh is called for two reasons: either a kprobe needs to be
* enabled/disabled (modname is NULL), or a module has been loaded/unloaded and
* kprobes need to be registered/unregistered (modname is !NULL). */
static void
stapkp_refresh(const char *modname,
struct stap_kprobe_probe *probes,
size_t nprobes)
{
size_t i;
dbug_stapkp("refresh %lu probes with module %s\n", nprobes, modname ?: "?");
#ifdef STAPCONF_KALLSYMS_ON_EACH_SYMBOL
if (modname) {
size_t probe_max = 0;
for (i = 0; i < nprobes; i++) {
struct stap_kprobe_probe *skp = &probes[i];
// If this probe is in the same module that is being
// loaded/unloaded and the probe is symbol_name+offset based
// and it isn't registered (so the module must be loaded),
// try to convert all probes in the same module to
// address-based probes.
if (skp->module && strcmp(modname, skp->module) == 0
&& skp->symbol_name && skp->registered_p == 0)
++probe_max;
}
if (probe_max > 0) {
struct stapkp_symbol_data sd;
sd.probes = probes;
sd.nprobes = nprobes;
sd.probe_max = probe_max;
sd.modname = modname;
preempt_disable();
kallsyms_on_each_symbol(stapkp_symbol_callback, &sd);
preempt_enable();
}
}
#endif
for (i = 0; i < nprobes; i++) {
struct stap_kprobe_probe *skp = &probes[i];
// was this probe's target module loaded/unloaded
if (modname && skp->module
&& strcmp(modname, skp->module) == 0) {
int rc;
unsigned long addr = (! skp->symbol_name
? stapkp_relocate_addr(skp) : 0);
// module being loaded?
if (skp->registered_p == 0 && (addr != 0 || skp->symbol_name))
stapkp_register_probe(skp);
// module/section being unloaded?
else if (skp->registered_p == 1 && addr == 0)
stapkp_unregister_probe(skp);
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30)
else if (stapkp_should_enable_probe(skp)
|| stapkp_should_disable_probe(skp)) {
stapkp_refresh_probe(skp);
}
#endif
}
}
