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cd69fedf58
It turns out that arch/x86/events/intel/core.c makes use of "empty"
attributes.
static struct attribute *empty_attrs;
__init int intel_pmu_init(void)
{
struct attribute **extra_skl_attr = &empty_attrs;
struct attribute **extra_attr = &empty_attrs;
struct attribute **td_attr = &empty_attrs;
struct attribute **mem_attr = &empty_attrs;
struct attribute **tsx_attr = &empty_attrs;
...
That breaks the assumption __first_visible() that expects that if
grp->attrs is set then grp->attrs[0] must also be set and results in
backtraces like:
BUG: kernel NULL pointer dereference, address: 00rnel mode
#PF: error_code(0x0000) - not-present ] PREEMPT SMP NOPTI
CPU: 1 PID: 1 Comm: swapper/IP: 0010:exra_is_visible+0x14/0x20
? exc_page_fault+0x68/0x190
internal_create_groups+0x42/0xa0
pmu_dev_alloc+0xc0/0xe0
perf_event_sysfs_init+0x580000000000 ]---
RIP: 0010:exra_is_visible+0x14/0
Check for non-empty attributes array before calling is_visible().
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Closes: https://github.com/thesofproject/linux/pull/4799#issuecomment-1958537212
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.