[DTrace-devel] [PATCH 1/2] uprobes: name uprobes based on offset in inode rather than address

[Kris Van Hees]

When PIC code is used, USDT probes (using uprobes) can appear at different
addresses for distinct instances of the same ELF object because the base
address is not fixed.  As a result, uprobes were being created using names
that were not stable.  Since (dev, inode, offset) is a unique triplet for
any uprobe, use that instead of (dev, inode, address).

Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
---
 libcommon/uprobes.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libcommon/uprobes.c b/libcommon/uprobes.c
index cf82882c..3bb423fc 100644
--- a/libcommon/uprobes.c
+++ b/libcommon/uprobes.c
@@ -307,6 +307,7 @@ uprobe_create_from_addr(ps_prochandle *P, uint64_t addr, int is_enabled,
 	if (!spec)
 		return NULL;
 
+	addr -= mapp.pr_file->first_segment->pr_vaddr;
 	name = uprobe_create_named(mapp.pr_dev, mapp.pr_inum, addr, spec, 0,
 				   is_enabled, prv, mod, fun, prb);
 	free(spec);
-- 
2.40.1