/* The task_finder_callback we use for ET_EXEC targets.
We used to perform uprobe insertion/removal here, but not any more.
(PR10524) */
static int stap_uprobe_process_found (struct stap_task_finder_target *tgt, struct task_struct *tsk, int register_p, int process_p) {
const struct stap_uprobe_tf *stf = container_of(tgt, struct stap_uprobe_tf, finder);
if (! process_p) return 0; /* ignore threads */
dbug_task_vma(1, "%cproc pid %d stf %p %p path %s\n", register_p?'+':'-', tsk->tgid, tgt, stf, stf->pathname);
/* ET_EXEC events are like shlib events, but with 0 relocation bases */
if (register_p) {
int rc = stap_uprobe_change_plus (tsk, 0, TASK_SIZE, stf, 0, 0);
stap_uprobe_change_semaphore_plus (tsk, 0, TASK_SIZE, stf);
return rc;
} else
return stap_uprobe_change_minus (tsk, 0, TASK_SIZE, stf);
}
/* The task_finder_mmap_callback */
static int
stap_uprobe_mmap_found (struct stap_task_finder_target *tgt,
struct task_struct *tsk, char *path,
struct dentry *dentry, unsigned long addr,
unsigned long length, unsigned long offset,
unsigned long vm_flags)
{
int rc = 0;
const struct stap_uprobe_tf *stf = container_of(tgt, struct stap_uprobe_tf, finder);
/* 1 - shared libraries' executable segments load from offset 0
* - ld.so convention offset != 0 is now allowed
* so stap_uprobe_change_plus can set a semaphore,
* i.e. a static extern, in a shared object
* 2 - the shared library we're interested in
* 3 - mapping should be executable or writable (for semaphore in .so)
* NB: or both, on kernels that lack noexec mapping
*/
if (path == NULL || strcmp (path, stf->pathname))
return 0;
/* Check non-writable, executable sections for probes. */
if ((vm_flags & VM_EXEC) && !(vm_flags & VM_WRITE)) {
dbug_task_vma (1,
"+mmap X pid %d path %s addr %p length %u offset %p stf %p %p path %s\n",
tsk->tgid, path, (void *) addr, (unsigned)length, (void*) offset,
tgt, stf, stf->pathname);
rc = stap_uprobe_change_plus (tsk, addr, length, stf, offset, vm_flags);
}
/* Check writable sections for semaphores.
* NB: They may have also been executable for the check above, if we're
* running a kernel that lacks noexec mappings. So long as there's
* no error (rc == 0), we need to look for semaphores too.
*/
if ((rc == 0) && (vm_flags & VM_WRITE)) {
dbug_task_vma (1,
"+mmap W pid %d path %s addr %p length %u offset %p stf %p %p path %s\n",
tsk->tgid, path, (void *) addr, (unsigned)length, (void*) offset,
tgt, stf, stf->pathname);
rc = stap_uprobe_change_semaphore_plus (tsk, addr, length, stf);
}
return rc;
}
/* The task_finder_mmap_callback */
static int stap_uprobe_mmap_found (struct stap_task_finder_target *tgt, struct task_struct *tsk, char *path, struct dentry *dentry, unsigned long addr, unsigned long length, unsigned long offset, unsigned long vm_flags) {
const struct stap_uprobe_tf *stf = container_of(tgt, struct stap_uprobe_tf, finder);
/* 1 - shared libraries' executable segments load from offset 0
- ld.so convention offset != 0 is now allowed
so stap_uprobe_change_plus can set a semaphore,
i.e. a static extern, in a shared object
2 - the shared library we're interested in
3 - mapping should be executable or writeable (for semaphore in .so) */
if (path == NULL || strcmp (path, stf->pathname)) return 0;
if (vm_flags & VM_EXEC) {
#ifdef DEBUG_TASK_FINDER_VMA
_stp_dbug (__FUNCTION__,__LINE__, "+mmap R-X pid %d path %s addr %p length %u offset %p stf %p %p path %s\n", tsk->tgid, path, (void *) addr, (unsigned)length, (void*) offset, tgt, stf, stf->pathname);
#endif
return stap_uprobe_change_plus (tsk, addr, length, stf, offset, vm_flags);
} else if (vm_flags & VM_WRITE) {
#ifdef DEBUG_TASK_FINDER_VMA
_stp_dbug (__FUNCTION__,__LINE__, "+mmap RW- pid %d path %s addr %p length %u offset %p stf %p %p path %s\n", tsk->tgid, path, (void *) addr, (unsigned)length, (void*) offset, tgt, stf, stf->pathname);
#endif
return stap_uprobe_change_semaphore_plus (tsk, addr, length, stf);
} else return 0;
}