process maps: Check why agent fails to find referred mapped object

[kakkoyun]

level=warn ts=2022-08-04T12:14:20.873202543Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/26597/root/usr/lib/libexpat.so.1.8.8 err="failed to open elf: open /proc/26597/root/usr/lib/libexpat.so.1.8.8: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974094999Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libm.so.6 err="failed to open elf: open /proc/72167/root/usr/lib/libm.so.6: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974109479Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libexpat.so.1.8.8 err="failed to open elf: open /proc/72167/root/usr/lib/libexpat.so.1.8.8: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974124849Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libdbus-1.so.3.32.0 err="failed to open elf: open /proc/72167/root/usr/lib/libdbus-1.so.3.32.0: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974139679Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libdrm.so.2.4.0 err="failed to open elf: open /proc/72167/root/usr/lib/libdrm.so.2.4.0: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974155249Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libgio-2.0.so.0.7200.3 err="failed to open elf: open /proc/72167/root/usr/lib/libgio-2.0.so.0.7200.3: no such file or directory"
level=warn ts=2022-08-04T12:13:50.9741707Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libcups.so.2 err="failed to open elf: open /proc/72167/root/usr/lib/libcups.so.2: no such file or directory"
level=warn ts=2022-08-04T12:13:50.97418925Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libatk-bridge-2.0.so.0.0.0 err="failed to open elf: open /proc/72167/root/usr/lib/libatk-bridge-2.0.so.0.0.0: no such file or directory"
level=warn ts=2022-08-04T12:13:50.97420458Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libatk-1.0.so.0.23809.1 err="failed to open elf: open /proc/72167/root/usr/lib/libatk-1.0.so.0.23809.1: no such file or directory"
level=warn ts=2022-08-04T12:13:50.97422049Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libnspr4.so err="failed to open elf: open /proc/72167/root/usr/lib/libnspr4.so: no such file or directory"
level=warn ts=2022-08-04T12:13:50.97423528Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libsmime3.so err="failed to open elf: open /proc/72167/root/usr/lib/libsmime3.so: no such file or directory"
level=warn ts=2022-08-04T12:13:50.97425043Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libnssutil3.so err="failed to open elf: open /proc/72167/root/usr/lib/libnssutil3.so: no such file or directory"
level=warn ts=2022-08-04T12:13:50.97426537Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libnss3.so err="failed to open elf: open /proc/72167/root/usr/lib/libnss3.so: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974281051Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libglib-2.0.so.0.7200.3 err="failed to open elf: open /proc/72167/root/usr/lib/libglib-2.0.so.0.7200.3: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974295901Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libgobject-2.0.so.0.7200.3 err="failed to open elf: open /proc/72167/root/usr/lib/libgobject-2.0.so.0.7200.3: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974311351Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libpthread.so.0 err="failed to open elf: open /proc/72167/root/usr/lib/libpthread.so.0: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974326031Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/libdl.so.2 err="failed to open elf: open /proc/72167/root/usr/lib/libdl.so.2: no such file or directory"
level=warn ts=2022-08-04T12:13:50.974340531Z caller=maps.go:106 msg="failed to read object build ID" object=/proc/72167/root/usr/lib/ld-linux-x86-64.so.2 err="failed to open elf: open /proc/72167/root/usr/lib/ld-linux-x86-64.so.2: no such file or directory"

[brancz]

I suspect this is an artifact of a short-lived process that exited between reading the mapping and reading the object file. We could tell reasonably easily by checking if that process is still alive right after (that certainly leaves the possibility for that to be racy, but it would tell us if the process is actually still running in which case this is probably more severe).

[kakkoyun]

We have improved the support of the short-lived processes as much as we can, but this can still occur, even if it's seldom.