No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Steven Rostedt (VMware) a69af5baed ftrace: Handle tracing when switching between context
commit 726b3d3f141fba6f841d715fc4d8a4a84f02c02a upstream.

When an interrupt or NMI comes in and switches the context, there's a delay
from when the preempt_count() shows the update. As the preempt_count() is
used to detect recursion having each context have its own bit get set when
tracing starts, and if that bit is already set, it is considered a recursion
and the function exits. But if this happens in that section where context
has changed but preempt_count() has not been updated, this will be
incorrectly flagged as a recursion.

To handle this case, create another bit call TRANSITION and test it if the
current context bit is already set. Flag the call as a recursion if the
TRANSITION bit is already set, and if not, set it and continue. The
TRANSITION bit will be cleared normally on the return of the function that
set it, or if the current context bit is clear, set it and clear the
TRANSITION bit to allow for another transition between the current context
and an even higher one.

Cc: stable@vger.kernel.org
Fixes: edc15cafcb ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 12:37:28 +01:00
arch arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S 2020-11-10 12:37:24 +01:00
block
certs
crypto
Documentation linkage: Introduce new macros for assembler symbols 2020-11-10 12:37:24 +01:00
drivers mtd: spi-nor: Don't copy self-pointing struct around 2020-11-10 12:37:28 +01:00
fs gfs2: Wake up when sd_glock_disposal becomes zero 2020-11-10 12:37:27 +01:00
include mm: always have io_remap_pfn_range() set pgprot_decrypted() 2020-11-10 12:37:27 +01:00
init printk: reduce LOG_BUF_SHIFT range for H8300 2020-11-05 11:43:16 +01:00
ipc
kernel ftrace: Handle tracing when switching between context 2020-11-10 12:37:28 +01:00
lib lib/crc32test: remove extra local_irq_disable/enable 2020-11-10 12:37:27 +01:00
LICENSES
mm mm: mempolicy: fix potential pte_unmap_unlock pte error 2020-11-10 12:37:27 +01:00
net sctp: Fix COMM_LOST/CANT_STR_ASSOC err reporting on big-endian platforms 2020-11-10 12:37:26 +01:00
samples samples/bpf: Fix possible deadlock in xdpsock 2020-11-05 11:43:17 +01:00
scripts
security evm: Check size of security.evm before using it 2020-11-01 12:01:05 +01:00
sound ALSA: usb-audio: Add implicit feedback quirk for MODX 2020-11-10 12:37:27 +01:00
tools perf python scripting: Fix printable strings in python3 scripts 2020-11-05 11:43:32 +01:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.75 2020-11-05 11:43:38 +01:00
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.