On Mon, Mar 20, 2023 at 12:53:00PM +0100, Laszlo Ersek wrote: > In "kernel-5.14.0-269.el9", the "kernel-modules-core" subpackage got split > from the "kernel-core" subpackage. Therefore, a single binary RPM > containing *both* the "/boot/vmlinuz-5.14.0-269.el9.x86_64" file *and* the > "/lib/modules/5.14.0-269.el9.x86_64" directory no longer exists. The file > now belongs to "kernel-core", and the directory to "kernel-modules-core". > > As a result, when we investigate the file list of "kernel-core" (based on > "kernel-core" providing "/boot/vmlinuz-5.14.0-269.el9.x86_64"), the first > match against "/lib/modules/" is not the actual module root directory > "/lib/modules/5.14.0-269.el9.x86_64", but the nonsensical > "/lib/modules/5.14.0-269.el9.x86_64/.vmlinuz.hmac" regular file. This > latter file is never a directory, therefore we rule out "kernel-core" as a > kernel package. > > We also rule out "kernel-modules-core" (even earlier) because it does not > contain "/boot/vmlinuz-5.14.0-269.el9.x86_64". > > Now, the code already deals with the case if the prospective kernel > package *does not provide a match* for the "/lib/modules/" prefix: in that > case, we construct the modpath manually, from said prefix, and the version > number found in "/boot/vmlinuz-<version>". This fallback is good, but it's > unreachable if *there is* a candidate, it's just wrong (i.e., not a > directory). > > Perform the "is_dir" check on the candidate modpath earlier, so that we > can fall back to the manual modpath construction if the modpath candidate > exists, but is wrong. > > With this, the original "is_dir" check becomes superfluous (duplicated) > *except* when the "Not_found" branch is taken. Therefore, hoist the > original "is_dir" check into that branch. > > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2175703 > Reported-by: Vera Wu <vwu(a)redhat.com&gt; > Signed-off-by: Laszlo Ersek <lersek(a)redhat.com&gt; > Tested-by: Vera Wu <vwu(a)redhat.com&gt; > --- > > Notes: > context:-U5 > > mldrivers/linux_kernels.ml | 24 +++++++++++++++----- > 1 file changed, 18 insertions(+), 6 deletions(-) > > diff --git a/mldrivers/linux_kernels.ml b/mldrivers/linux_kernels.ml > index 5b8bdee9923d..23ff76a5504c 100644 > --- a/mldrivers/linux_kernels.ml > +++ b/mldrivers/linux_kernels.ml > @@ -125,31 +125,43 @@ let detect_kernels (g : G.guestfs) root bootloader apps = > *) > let modpath, version = > let prefix = "/lib/modules/" in > let prefix_len = String.length prefix in > try > - List.find_map ( > + let modpath, version = List.find_map ( > fun filename -> > let filename_len = String.length filename in > if filename_len > prefix_len && > String.is_prefix filename prefix then ( > let version = String.sub filename prefix_len > (filename_len - prefix_len) in > Some (filename, version) > ) else > None > - ) files > + ) files in > + (* Fall back to the version in the vmlinuz file name not only if > + * a candidate pathname couldn't be found under /lib/modules/, > + * but also in case the candidate pathname doesn't reference a > + * directory. See RHBZ#2175703. > + * > + * Note that this "is_dir" check is deliberately kept outside of > + * the "find_map"'s mapper function above: we want the first > + * candidate *to be* a directory, and not the first candidate > + * *that is* a directory. > + *) > + if not (g#is_dir ~followsymlinks:true modpath) then > + raise Not_found; > + modpath, version > with Not_found -> > let version = > String.sub vmlinuz 14 (String.length vmlinuz - 14) in > let modpath = prefix ^ version in > + (* Check that the modpath exists. *) > + if not (g#is_dir ~followsymlinks:true modpath) then > + raise Not_found; > modpath, version in > > - (* Check that the modpath exists. *) > - if not (g#is_dir ~followsymlinks:true modpath) then > - raise Not_found; > - > (* Find the initramfs which corresponds to the kernel. > * Since the initramfs is built at runtime, and doesn't have > * to be covered by the RPM file list, this is basically > * guesswork. > *) I see it's upstream, but anyway a late: ACK

That detect_kernels function is horribly complicated and hard to follow. At some point we need to attack it and split it up into manageable chunks.