* Re: [PATCH -v1 1/2] x86/microcode: Add microcode= cmdline parsing
[not found] ` <20250904113752.GDaLl6ELJRd3LZYBQl@fat_crate.local>
@ 2025-09-04 23:29 ` Nathan Chancellor
2025-09-05 10:40 ` Borislav Petkov
2025-09-05 13:17 ` Ryusuke Konishi
0 siblings, 2 replies; 4+ messages in thread
From: Nathan Chancellor @ 2025-09-04 23:29 UTC (permalink / raw)
To: Borislav Petkov
Cc: kernel test robot, Borislav Petkov, oe-lkp, lkp, linux-doc,
linux-kernel, X86 ML, Chang S. Bae, Sohil Mehta, Ryusuke Konishi,
linux-nilfs
Hi Boris and the Intel folks,
+ Ryusuke and linux-nilfs
On Thu, Sep 04, 2025 at 01:37:52PM +0200, Borislav Petkov wrote:
> On Tue, Sep 02, 2025 at 04:45:12PM +0800, kernel test robot wrote:
> >
> >
> > Hello,
> >
> >
> > this could be a noise, we didn't see the relation between the patch with the
> > issue we observed. however, we rebuild the kernels for both this commit and
> > parent 3 times.
> > (
> > our bot chose 894af4a1cde61c as the parent as below
> > * 19f370d45aceea x86/microcode: Add microcode= cmdline parsing
> > * 894af4a1cde61c (tip/x86/core, peterz-queue/x86/core) objtool: Validate kCFI calls
> > )
> >
> > and for each rerun of both this commit and parent, we run more times, but the
> > issue is still quite persistent while parent keeps clean:
> >
> > =========================================================================================
> > tbox_group/testcase/rootfs/kconfig/compiler/runtime/group/nr_groups:
> > vm-snb/trinity/debian-11.1-i386-20220923.cgz/x86_64-randconfig-006-20250826/clang-20/300s/group-01/5
> >
> > 894af4a1cde61c34 19f370d45aceea5ab4c52e3afa0
> > ---------------- ---------------------------
> > fail:runs %reproduction fail:runs
> > | | |
> > :200 74% 149:200 last_state.is_incomplete_run
> > :200 74% 147:200 last_state.running
> > :200 75% 150:200 dmesg.CFI_failure_at_kobj_attr_show
> > :200 75% 150:200 dmesg.Kernel_panic-not_syncing:Fatal_exception
> > :200 75% 150:200 dmesg.Oops:invalid_opcode:#[##]KASAN
> > :200 75% 150:200 dmesg.RIP:kobj_attr_show
> > :200 75% 150:200 dmesg.boot_failures
> >
> > so we just follow our report rule to still report this results FYI.
> >
> > if it's really irrelevant, sorry maybe our env issues (though we still cannot
> > figure out for now). and if you can help us to figure out the potential problem
> > from our dmesg in below link, it will be very apprecidated!
>
> Yeah, I don't know what you did here but building with that .config, I can't
> even boot that kernel in a VM because doing:
>
> qemu-... -kernel bzImage ...
>
> sends me into grub and asks me to select the default kernel.
>
> And my qemu script boots arbitrary kernels just fine.
Does your QEMU boot via UEFI? This configuration has
# CONFIG_EFI is not set
so if I try to boot QEMU via OVMF, I get:
BdsDxe: failed to load Boot0002 "UEFI Non-Block Boot Device" from VenMedia(1428F772-B64A-441E-B8C3-9EBDD7F893C7): Not Found
BdsDxe: No bootable option or device was found.
BdsDxe: Press any key to enter the Boot Manager Menu.
Turning on CONFIG_EFI and CONFIG_EFI_STUB is enough for me to boot this
configuration.
> Also, I used clang-20 from here:
>
> https://mirrors.edge.kernel.org/pub/tools/llvm/
>
> and version 20.1.8 took something like ~10(!) minutes to link vmlinux with
> that config. Just FYI for Nathan, maybe something's weird there.
Looks like this configuration has
CONFIG_LTO_CLANG_FULL=y
so that's not too surprising :) turning that off or making it
CONFIG_LTO_CLANG_THIN=y
should be much quicker.
> > below is full report.
>
> Leaving it in.
As for the actual report...
I ran 200 boots using our simple Buildroot initrd and QEMU wrapper
script [1] and saw no issues, however...
[1]: https://github.com/ClangBuiltLinux/boot-utils
> > kernel test robot noticed "CFI_failure_at_kobj_attr_show" on:
> >
> > commit: 19f370d45aceea5ab4c52e3afa00226fb99c3fc8 ("[PATCH -v1 1/2] x86/microcode: Add microcode= cmdline parsing")
> > url: https://github.com/intel-lab-lkp/linux/commits/Borislav-Petkov/x86-microcode-Add-microcode-cmdline-parsing/20250820-215624
> > base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 894af4a1cde61c3401f237184fb770f72ff12df8
> > patch link: https://lore.kernel.org/all/20250820135043.19048-2-bp@kernel.org/
> > patch subject: [PATCH -v1 1/2] x86/microcode: Add microcode= cmdline parsing
> >
> > in testcase: trinity
> > version: trinity-i386-abe9de86-1_20230429
> > with following parameters:
> >
> > runtime: 300s
> > group: group-01
> > nr_groups: 5
> >
> >
> >
> > config: x86_64-randconfig-006-20250826
> > compiler: clang-20
> > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> >
> > (please refer to attached dmesg/kmsg for entire log/backtrace)
> >
> >
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <oliver.sang@intel.com>
> > | Closes: https://lore.kernel.org/oe-lkp/202509021646.bc78d9ef-lkp@intel.com
> >
> >
> > The kernel config and materials to reproduce are available at:
> > https://download.01.org/0day-ci/archive/20250902/202509021646.bc78d9ef-lkp@intel.com
> >
> >
> > [ 453.382281][ T7761] CFI failure at kobj_attr_show+0x59/0x80 (target: nilfs_feature_revision_show+0x0/0x30; expected type: 0x1b8aae92)
I am surprised that this was not reproducible at 894af4a1cde61c34 for
the Intel folks because it does for me assuming I actually try to read
that file (maybe trinity was not hitting it on the older revision?):
$ cat /sys/fs/nilfs2/features/revision
[ 6.975426][ T150] CFI failure at kobj_attr_show+0x59/0x80 (target: nilfs_feature_revision_show+0x0/0x30; expected type: 0xed60cafc)
[ 6.976822][ T150] Oops: invalid opcode: 0000 [#1] KASAN
[ 6.977407][ T150] CPU: 0 UID: 0 PID: 150 Comm: cat Not tainted 6.17.0-rc2-00016-g894af4a1cde6 #1 NONE
[ 6.978432][ T150] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 6.979752][ T150] RIP: 0010:kobj_attr_show+0x59/0x80
[ 6.980321][ T150] Code: 08 00 74 08 4c 89 e7 e8 05 6b d6 fb 4d 8b 1c 24 4d 85 db 74 1f 4c 89 ff 4c 89 f6 48 89 da 41 ba 04 35 9f 12 45 03 53 f1 74 02 <0f> 0b 41 ff d3 0f 1f 00 eb 07 48 c7 c0 fb ff ff ff 5b 41 5c 41 5e
[ 6.982456][ T150] RSP: 0018:ffa0000000e17b28 EFLAGS: 00010216
[ 6.983163][ T150] RAX: 1ffffffff3753765 RBX: ff11000109eca000 RCX: dffffc0000000000
[ 6.984012][ T150] RDX: ff11000109eca000 RSI: ffffffff9ba9bb00 RDI: ff11000100b4f250
[ 6.984900][ T150] RBP: ffa0000000e17b48 R08: ff11000109ecafff R09: ff11000109eca000
[ 6.985830][ T150] R10: 000000007b3f6fc3 R11: ffffffff9541ea80 R12: ffffffff9ba9bb28
[ 6.986658][ T150] R13: 1fe2200020fdfe80 R14: ffffffff9ba9bb00 R15: ff11000100b4f250
[ 6.987542][ T150] FS: 00007f4818d2b740(0000) GS:0000000000000000(0000) knlGS:0000000000000000
[ 6.988508][ T150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6.989241][ T150] CR2: 00007f481899a000 CR3: 0000000109f3b002 CR4: 0000000000371eb0
[ 6.990120][ T150] Call Trace:
[ 6.990498][ T150] <TASK>
[ 6.990867][ T150] sysfs_kf_seq_show+0x2a6/0x390
[ 6.991410][ T150] ? __cfi_kobj_attr_show+0x10/0x10
[ 6.992015][ T150] kernfs_seq_show+0x104/0x15b
[ 6.992542][ T150] seq_read_iter+0x580/0xe2b
[ 6.993076][ T150] kernfs_fop_read_iter+0x137/0x470
[ 6.993650][ T150] new_sync_read+0x27e/0x365
[ 6.994185][ T150] vfs_read+0x1e8/0x46b
[ 6.994650][ T150] ksys_read+0xc2/0x170
[ 6.995129][ T150] __x64_sys_read+0x7f/0x90
[ 6.995631][ T150] ? entry_SYSCALL_64_after_hwframe+0x6b/0x73
[ 6.996299][ T150] x64_sys_call+0x2589/0x2cdb
[ 6.996843][ T150] do_syscall_64+0x89/0xfa0
[ 6.997343][ T150] ? irqentry_exit+0x33/0x70
[ 6.997882][ T150] ? exc_page_fault+0x96/0xe0
[ 6.998400][ T150] entry_SYSCALL_64_after_hwframe+0x6b/0x73
[ 6.999068][ T150] RIP: 0033:0x7f4818dc11ce
[ 6.999564][ T150] Code: 4d 89 d8 e8 64 be 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa
[ 7.001627][ T150] RSP: 002b:00007ffc2d325600 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
[ 7.002558][ T150] RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f4818dc11ce
[ 7.003443][ T150] RDX: 0000000000040000 RSI: 00007f481899b000 RDI: 0000000000000003
[ 7.004363][ T150] RBP: 00007ffc2d325610 R08: 0000000000000000 R09: 0000000000000000
[ 7.005260][ T150] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000040000
[ 7.006143][ T150] R13: 00007f481899b000 R14: 0000000000000003 R15: 0000000000000000
[ 7.007027][ T150] </TASK>
[ 7.007411][ T150] Modules linked in:
[ 7.007994][ T150] ---[ end trace 0000000000000000 ]---
[ 7.008711][ T150] RIP: 0010:kobj_attr_show+0x59/0x80
[ 7.009430][ T150] Code: 08 00 74 08 4c 89 e7 e8 05 6b d6 fb 4d 8b 1c 24 4d 85 db 74 1f 4c 89 ff 4c 89 f6 48 89 da 41 ba 04 35 9f 12 45 03 53 f1 74 02 <0f> 0b 41 ff d3 0f 1f 00 eb 07 48 c7 c0 fb ff ff ff 5b 41 5c 41 5e
[ 7.011712][ T150] RSP: 0018:ffa0000000e17b28 EFLAGS: 00010216
[ 7.012369][ T150] RAX: 1ffffffff3753765 RBX: ff11000109eca000 RCX: dffffc0000000000
[ 7.013214][ T150] RDX: ff11000109eca000 RSI: ffffffff9ba9bb00 RDI: ff11000100b4f250
[ 7.014202][ T150] RBP: ffa0000000e17b48 R08: ff11000109ecafff R09: ff11000109eca000
[ 7.015201][ T150] R10: 000000007b3f6fc3 R11: ffffffff9541ea80 R12: ffffffff9ba9bb28
[ 7.016202][ T150] R13: 1fe2200020fdfe80 R14: ffffffff9ba9bb00 R15: ff11000100b4f250
[ 7.017212][ T150] FS: 00007f4818d2b740(0000) GS:0000000000000000(0000) knlGS:0000000000000000
[ 7.018332][ T150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.019154][ T150] CR2: 00007f481899a000 CR3: 0000000109f3b002 CR4: 0000000000371eb0
[ 7.020147][ T150] Kernel panic - not syncing: Fatal exception
[ 7.020837][ T150] Kernel Offset: 0x12e00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
The fix should be something like the following, which resolves the issue
for me.
nilfs_sysfs_init() ->
kset_create_and_add() ->
kset_create()
has
kset->kobj.ktype = &kset_ktype
which is
static const struct kobj_type kset_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = kset_release,
.get_ownership = kset_get_ownership,
};
Note the kobj_sysfs_ops.
const struct sysfs_ops kobj_sysfs_ops = {
.show = kobj_attr_show,
.store = kobj_attr_store,
};
nilfs_feature_attr_group is added to the nilfs_kset->kobj via
sysfs_create_group(), where the kernfs_ops for each file in
nilfs_feature_attr_group becomes
sysfs_create_group() ->
internal_create_group() ->
create_files() ->
sysfs_add_file_mode_ns() ->
ops = &sysfs_file_kfops_rw;
__kernfs_create_file() ->
kn->attr.ops = ops;
static const struct kernfs_ops sysfs_file_kfops_rw = {
.seq_show = sysfs_kf_seq_show,
.write = sysfs_kf_write,
};
sysfs_kf_seq_show() calls kobj_attr_show() via
const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
...
count = ops->show(kobj, of->kn->priv, buf);
kobj_attr_show() calls one of the nilfs_feature_*_show() functions via
after casting to 'struct kobj_attribute':
kattr = container_of(attr, struct kobj_attribute, attr);
if (kattr->show)
ret = kattr->show(kobj, kattr, buf);
struct kobj_attribute {
struct attribute attr;
ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
char *buf);
ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count);
};
So the types of nilfs_feature_*_show() need to match
kobj_attribute->show() to avoid triggering CFI here.
Cheers,
Nathan
diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 14868a3dd592..bc52afbfc5c7 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -1075,7 +1075,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
************************************************************************/
static ssize_t nilfs_feature_revision_show(struct kobject *kobj,
- struct attribute *attr, char *buf)
+ struct kobj_attribute *attr, char *buf)
{
return sysfs_emit(buf, "%d.%d\n",
NILFS_CURRENT_REV, NILFS_MINOR_REV);
@@ -1087,7 +1087,7 @@ static const char features_readme_str[] =
"(1) revision\n\tshow current revision of NILFS file system driver.\n";
static ssize_t nilfs_feature_README_show(struct kobject *kobj,
- struct attribute *attr,
+ struct kobj_attribute *attr,
char *buf)
{
return sysfs_emit(buf, features_readme_str);
diff --git a/fs/nilfs2/sysfs.h b/fs/nilfs2/sysfs.h
index 78a87a016928..d370cd5cce3f 100644
--- a/fs/nilfs2/sysfs.h
+++ b/fs/nilfs2/sysfs.h
@@ -50,16 +50,16 @@ struct nilfs_sysfs_dev_subgroups {
struct completion sg_segments_kobj_unregister;
};
-#define NILFS_COMMON_ATTR_STRUCT(name) \
+#define NILFS_KOBJ_ATTR_STRUCT(name) \
struct nilfs_##name##_attr { \
struct attribute attr; \
- ssize_t (*show)(struct kobject *, struct attribute *, \
+ ssize_t (*show)(struct kobject *, struct kobj_attribute *, \
char *); \
- ssize_t (*store)(struct kobject *, struct attribute *, \
+ ssize_t (*store)(struct kobject *, struct kobj_attribute *, \
const char *, size_t); \
}
-NILFS_COMMON_ATTR_STRUCT(feature);
+NILFS_KOBJ_ATTR_STRUCT(feature);
#define NILFS_DEV_ATTR_STRUCT(name) \
struct nilfs_##name##_attr { \
^ permalink raw reply related [flat|nested] 4+ messages in thread