Em Tue, Oct 04, 2022 at 03:10:06PM -0600, Bitweasil escreveu: > When trying to extract the layout of kernel structures that should exist on > recent kernels from the Ubuntu debug kernel repo, I get the following error: > > die__process: DW_TAG_compile_unit, DW_TAG_type_unit or DW_TAG_partial_unit > expected got INVALID! > pahole: type 'mount' not found > > As far as I can tell, 'struct mount' should still exist - and I can pull > other structures out without trouble. The issue starts appearing somewhere > in the 5.15 kernel version - earlier kernels work exactly as expected and I > can extract the full offsets. > > https://elixir.bootlin.com/linux/v5.15.48/source/fs/mount.h indicates that > 'struct mount' still exists in the source, and it remains present into the > 6.0 kernel with no substantial changes. I can also produce the same response > with some of the other structures in that file - mountpoint, mnt_namespace, > and mnt_pcp all lead to the same error message. > > I've tried building pahole from head (Oct 4, 2022, e819d737) without any > changes to the behavior, and v1.21 and 1.24 both lead to the same results. Are you sure? The error message should be this in 1.24: because: if (tag == DW_TAG_skeleton_unit) { static bool warned; if (!warned) { fprintf(stderr, "WARNING: DW_TAG_skeleton_unit used, please look for a .dwo file and use it instead.\n" " A future version of pahole will support do this automagically.\n"); warned = true; } return 0; // so that other units can be processed } if (tag == DW_TAG_partial_unit) { static bool warned; if (!warned) { fprintf(stderr, "WARNING: DW_TAG_partial_unit used, some types will not be considered!\n" " Probably this was optimized using a tool like 'dwz'\n" " A future version of pahole will support this.\n"); warned = true; } return 0; // so that other units can be processed } if (tag != DW_TAG_compile_unit && tag != DW_TAG_type_unit) { fprintf(stderr, "%s: DW_TAG_compile_unit, DW_TAG_type_unit, DW_TAG_partial_unit or DW_TAG_skeleton_unit expected got %s (0x%x)!\n", __FUNCTION__, dwarf_tag_name(tag), tag); return -EINVAL; } But its strange, there are no units other than DW_TAG_compile_unit in that vmlinux file: ⬢[acme@toolbox boot]$ readelf -wi vmlinux-5.15.0-48-generic | grep 'DW_TAG_.*_unit' | grep -v DW_TAG_compile_unit ⬢[acme@toolbox boot]$ > Steps to reproduce (warning, will take ~10GB - the unzipped kernel debug > symbols are rather large): > cd /tmp > wget http://ddebs.ubuntu.com/pool/main/l/linux/linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb > ar x linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb > tar -xf data.tar.xz > cd usr/lib/debug/boot > pahole -C mount vmlinux-5.15.0-48-generic > die__process: DW_TAG_compile_unit, DW_TAG_type_unit or DW_TAG_partial_unit > expected got INVALID! > pahole: type 'mount' not found > Any suggestions on how to resolve this? I'm not familiar enough with the > various debug formats to know how to troubleshoot beyond this point right > now. Works for me: ⬢[acme@toolbox pahole]$ wget http://ddebs.ubuntu.com/pool/main/l/linux/linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb --2022-10-05 09:11:56-- http://ddebs.ubuntu.com/pool/main/l/linux/linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb Resolving ddebs.ubuntu.com (ddebs.ubuntu.com)... 185.125.190.17, 91.189.91.48, 91.189.91.49, ... Connecting to ddebs.ubuntu.com (ddebs.ubuntu.com)|185.125.190.17|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 1055842672 (1007M) [application/vnd.debian.binary-package] Saving to: ‘linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb’ linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.dde 100%[===================================================================================================================================================================>] 1007M 13.3MB/s in 74s 2022-10-05 09:13:11 (13.5 MB/s) - ‘linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb’ saved [1055842672/1055842672] ⬢[acme@toolbox pahole]$ mkdir ubuntu-kernel ⬢[acme@toolbox pahole]$ mv linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb ubuntu-kernel ⬢[acme@toolbox pahole]$ cd ubuntu-kernel ⬢[acme@toolbox ubuntu-kernel]$ ls -la total 1031148 drwxr-xr-x. 1 acme acme 138 Oct 5 09:13 . drwxrwxr-x. 1 acme acme 5074 Oct 5 09:13 .. -rw-r--r--. 1 acme acme 1055842672 Aug 31 08:39 linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb ⬢[acme@toolbox ubuntu-kernel]$ ar x linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb ⬢[acme@toolbox ubuntu-kernel]$ ls -la total 2062252 drwxr-xr-x. 1 acme acme 214 Oct 5 09:13 . drwxrwxr-x. 1 acme acme 5074 Oct 5 09:13 .. -rw-r--r--. 1 acme acme 155352 Oct 5 09:13 control.tar.xz -rw-r--r--. 1 acme acme 1055687128 Oct 5 09:13 data.tar.xz -rw-r--r--. 1 acme acme 4 Oct 5 09:13 debian-binary -rw-r--r--. 1 acme acme 1055842672 Aug 31 08:39 linux-image-unsigned-5.15.0-48-generic-dbgsym_5.15.0-48.54_amd64.ddeb ⬢[acme@toolbox ubuntu-kernel]$ tar -xf data.tar.xz ⬢[acme@toolbox ubuntu-kernel]$ cd usr/lib/debug/boot ⬢[acme@toolbox boot]$ ls -la total 719136 drwxr-xr-x. 1 acme acme 50 Aug 26 06:12 . drwxr-xr-x. 1 acme acme 14 Oct 5 09:13 .. -rw-r--r--. 1 acme acme 736393784 Aug 26 06:12 vmlinux-5.15.0-48-generic ⬢[acme@toolbox boot]$ ls -la total 719136 drwxr-xr-x. 1 acme acme 50 Aug 26 06:12 . drwxr-xr-x. 1 acme acme 14 Oct 5 09:13 .. -rw-r--r--. 1 acme acme 736393784 Aug 26 06:12 vmlinux-5.15.0-48-generic ⬢[acme@toolbox boot]$ pahole -C mount vmlinux-5.15.0-48-generic struct mount { struct hlist_node mnt_hash; /* 0 16 */ struct mount * mnt_parent; /* 16 8 */ struct dentry * mnt_mountpoint; /* 24 8 */ struct vfsmount mnt; /* 32 32 */ /* --- cacheline 1 boundary (64 bytes) --- */ union { struct callback_head mnt_rcu __attribute__((__aligned__(8))); /* 64 16 */ struct llist_node mnt_llist; /* 64 8 */ } __attribute__((__aligned__(8))); /* 64 16 */ struct mnt_pcp * mnt_pcp; /* 80 8 */ struct list_head mnt_mounts; /* 88 16 */ struct list_head mnt_child; /* 104 16 */ struct list_head mnt_instance; /* 120 16 */ /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */ const char * mnt_devname; /* 136 8 */ struct list_head mnt_list; /* 144 16 */ struct list_head mnt_expire; /* 160 16 */ struct list_head mnt_share; /* 176 16 */ /* --- cacheline 3 boundary (192 bytes) --- */ struct list_head mnt_slave_list; /* 192 16 */ struct list_head mnt_slave; /* 208 16 */ struct mount * mnt_master; /* 224 8 */ struct mnt_namespace * mnt_ns; /* 232 8 */ struct mountpoint * mnt_mp; /* 240 8 */ union { struct hlist_node mnt_mp_list; /* 248 16 */ struct hlist_node mnt_umount; /* 248 16 */ }; /* 248 16 */ /* --- cacheline 4 boundary (256 bytes) was 8 bytes ago --- */ struct list_head mnt_umounting; /* 264 16 */ struct fsnotify_mark_connector * mnt_fsnotify_marks; /* 280 8 */ __u32 mnt_fsnotify_mask; /* 288 4 */ int mnt_id; /* 292 4 */ int mnt_group_id; /* 296 4 */ int mnt_expiry_mark; /* 300 4 */ struct hlist_head mnt_pins; /* 304 8 */ struct hlist_head mnt_stuck_children; /* 312 8 */ /* size: 320, cachelines: 5, members: 27 */ /* forced alignments: 1 */ } __attribute__((__aligned__(8))); ⬢[acme@toolbox boot]$ pahole --version v1.24 ⬢[acme@toolbox boot]$ And it even has BTF info, which makes processing much faster but without some attributes: ⬢[acme@toolbox boot]$ readelf -SW vmlinux-5.15.0-48-generic | grep -i btf [28] .BTF PROGBITS ffffffff8279d1e0 199d1e0 4ef6b2 00 A 0 0 1 [29] .BTF_ids PROGBITS ffffffff82c8c894 1e8c894 0005e8 00 A 0 0 1 ⬢[acme@toolbox boot]$ ⬢[acme@toolbox boot]$ pahole -F btf -C mount vmlinux-5.15.0-48-generic struct mount { struct hlist_node mnt_hash; /* 0 16 */ struct mount * mnt_parent; /* 16 8 */ struct dentry * mnt_mountpoint; /* 24 8 */ struct vfsmount mnt; /* 32 32 */ /* --- cacheline 1 boundary (64 bytes) --- */ union { struct callback_head mnt_rcu; /* 64 16 */ struct llist_node mnt_llist; /* 64 8 */ }; /* 64 16 */ struct mnt_pcp * mnt_pcp; /* 80 8 */ struct list_head mnt_mounts; /* 88 16 */ struct list_head mnt_child; /* 104 16 */ struct list_head mnt_instance; /* 120 16 */ /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */ const char * mnt_devname; /* 136 8 */ struct list_head mnt_list; /* 144 16 */ struct list_head mnt_expire; /* 160 16 */ struct list_head mnt_share; /* 176 16 */ /* --- cacheline 3 boundary (192 bytes) --- */ struct list_head mnt_slave_list; /* 192 16 */ struct list_head mnt_slave; /* 208 16 */ struct mount * mnt_master; /* 224 8 */ struct mnt_namespace * mnt_ns; /* 232 8 */ struct mountpoint * mnt_mp; /* 240 8 */ union { struct hlist_node mnt_mp_list; /* 248 16 */ struct hlist_node mnt_umount; /* 248 16 */ }; /* 248 16 */ /* --- cacheline 4 boundary (256 bytes) was 8 bytes ago --- */ struct list_head mnt_umounting; /* 264 16 */ struct fsnotify_mark_connector * mnt_fsnotify_marks; /* 280 8 */ __u32 mnt_fsnotify_mask; /* 288 4 */ int mnt_id; /* 292 4 */ int mnt_group_id; /* 296 4 */ int mnt_expiry_mark; /* 300 4 */ struct hlist_head mnt_pins; /* 304 8 */ struct hlist_head mnt_stuck_children; /* 312 8 */ /* size: 320, cachelines: 5, members: 27 */ }; ⬢[acme@toolbox boot]$
