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Linux kernel modifications for the Kernel Hacking exam
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Mark Rutland 853e2dac25 arm64: perf: reject CHAIN events at creation time 
Currently it's possible for a user to open CHAIN events arbitrarily,
which we previously tried to rule out in commit:

  ca2b497253 ("arm64: perf: Reject stand-alone CHAIN events for PMUv3")

Which allowed the events to be opened, but prevented them from being
scheduled by by using an arm_pmu::filter_match hook to reject the
relevant events.

The CHAIN event filtering in the arm_pmu::filter_match hook was silently
removed in commit:

  bd27568117 ("perf: Rewrite core context handling")

As a result, it's now possible for users to open CHAIN events, and for
these to be installed arbitrarily.

Fix this by rejecting CHAIN events at creation time. This avoids the
creation of events which will never count, and doesn't require using the
dynamic filtering.

Attempting to open a CHAIN event (0x1e) will now be rejected:

| # ./perf stat -e armv8_pmuv3/config=0x1e/ ls
| perf
|
|  Performance counter stats for 'ls':
|
|    <not supported>      armv8_pmuv3/config=0x1e/
|
|        0.002197470 seconds time elapsed
|
|        0.000000000 seconds user
|        0.002294000 seconds sys

Other events (e.g. CPU_CYCLES / 0x11) will open as usual:

| # ./perf stat -e armv8_pmuv3/config=0x11/ ls
| perf
|
|  Performance counter stats for 'ls':
|
|            2538761      armv8_pmuv3/config=0x11/
|
|        0.002227330 seconds time elapsed
|
|        0.002369000 seconds user
|        0.000000000 seconds sys

Fixes: bd27568117 ("perf: Rewrite core context handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230216141240.3833272-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-02-16 21:23:52 +00:00
arch arm64: perf: reject CHAIN events at creation time 2023-02-16 21:23:52 +00:00
block treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto This update includes the following changes: 2022-12-14 12:31:09 -08:00
Documentation arm64: errata: Workaround possible Cortex-A715 [ESR|FAR]_ELx corruption 2023-01-06 17:14:55 +00:00
drivers arm_pmu: fix event CPU filtering 2023-02-16 21:23:52 +00:00
fs elfcore: Add a cprm parameter to elf_core_extra_{phdrs,data_size} 2023-01-05 15:12:12 +00:00
include arm_pmu: fix event CPU filtering 2023-02-16 21:23:52 +00:00
init Kbuild updates for v6.2 2022-12-19 12:33:32 -06:00
io_uring io_uring/net: fix cleanup after recycle 2022-12-19 08:28:28 -07:00
ipc Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
kernel kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
lib test_maple_tree: add test for mas_spanning_rebalance() on insufficient data 2022-12-21 14:31:52 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm hugetlb: really allocate vma lock for all sharable vmas 2022-12-21 14:31:52 -08:00
net treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
rust rust: types: add Opaque type 2022-12-04 01:59:16 +01:00
samples Char/Misc driver changes for 6.2-rc1 2022-12-16 03:49:24 -08:00
scripts modernize use of grep in coccicheck 2022-12-23 13:56:41 -08:00
security kernel hardening fixes for v6.2-rc1 2022-12-23 12:00:24 -08:00
sound treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
tools perf tools fixes and improvements for v6.2: 2nd batch 2022-12-22 11:07:29 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt ARM64: 2022-12-15 11:12:21 -08:00
.clang-format iommufd for 6.2 2022-12-14 09:15:43 -08:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore kbuild: Cleanup DT Overlay intermediate files as appropriate 2022-11-18 14:45:30 -06:00
.mailmap Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS MAINTAINERS: zram: zsmalloc: Add an additional co-maintainer 2022-12-15 16:37:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS io_uring-6.2-2022-12-19 2022-12-21 16:28:25 -08:00
Makefile Linux 6.2-rc1 2022-12-25 13:41:39 -08:00
README

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.