Go to file
Leo Yan 7100b12cf4 perf cs-etm: Generate branch sample for exception packet
The exception packet appears as one element with 'elem_type' ==
OCSD_GEN_TRC_ELEM_EXCEPTION or OCSD_GEN_TRC_ELEM_EXCEPTION_RET, which is
present for exception entry and exit respectively.  The decoder sets the
packet fields 'packet->exc' and 'packet->exc_ret' to indicate the
exception packets; but exception packets don't have a dedicated sample
type and shares the same sample type CS_ETM_RANGE with normal
instruction packets.

As a result, the exception packets are taken as normal instruction
packets and this introduces confusion in mixing different packet types.
Furthermore, these instruction range packets will be processed for
branch samples only when 'packet->last_instr_taken_branch' is true,
otherwise they will be omitted, this can introduce a mess for exception
and exception returning due to not having the complete address range
info for context switching.

To process exception packets properly, this patch introduces two new
sample types: CS_ETM_EXCEPTION and CS_ETM_EXCEPTION_RET; these two types
of packets will be handled by cs_etm__exception().  The function
cs_etm__exception() forces setting the previous CS_ETM_RANGE packet flag
'prev_packet->last_instr_taken_branch' to true, this matches well with
the program flow when the exception is trapped from user space to kernel
space, no matter if the most recent flow has branch taken or not; this
is also safe for returning to user space after exception handling.

After exception packets have their own sample type, the packet fields
'packet->exc' and 'packet->exc_ret' aren't needed anymore, so remove
them.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight ml <coresight@lists.linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-9-git-send-email-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-12-18 12:24:00 -03:00
arch kprobes/x86: Remove unneeded arch_within_kprobe_blacklist from x86 2018-12-17 17:48:40 +01:00
block block: Fix null_blk_zoned creation failure with small number of zones 2018-12-11 16:19:38 -07:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: user - Disable statistics interface 2018-12-07 13:56:08 +08:00
Documentation XArray updates for 4.20-rc7 2018-12-13 16:35:58 -08:00
drivers One fix for the qcom QCS404 clk driver that was merged for this release. 2018-12-14 12:14:41 -08:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge branch 'akpm' (patches from Andrew) 2018-12-14 15:35:30 -08:00
include kprobes: Blacklist symbols in arch-defined prohibited area 2018-12-17 17:48:38 +01:00
init psi: fix reference to kernel commandline enable 2018-12-14 15:05:45 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel kprobes: Blacklist symbols in arch-defined prohibited area 2018-12-17 17:48:38 +01:00
lib XArray: Fix xa_alloc when id exceeds max 2018-12-13 14:07:33 -05:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm hugetlbfs: call VM_BUG_ON_PAGE earlier in free_huge_page() 2018-12-14 15:05:45 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-09 15:12:33 -08:00
samples VFIO updates for v4.20 2018-10-31 11:01:38 -07:00
scripts scripts/spdxcheck.py: always open files in binary mode 2018-12-14 15:05:45 -08:00
security selinux/stable-4.20 PR 20181129 2018-11-29 10:15:06 -08:00
sound ALSA: hda/realtek: Enable audio jacks of ASUS UX433FN/UX333FA with ALC294 2018-12-10 11:25:22 +01:00
tools perf cs-etm: Generate branch sample for exception packet 2018-12-18 12:24:00 -03:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" 2018-10-26 16:25:19 -07:00
.clang-format page cache: Convert find_get_pages_contig to XArray 2018-10-21 10:46:34 -04:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap mailmap: Update email for Punit Agrawal 2018-11-05 10:02:11 +00:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: update entry for MMP platform 2018-12-03 12:39:57 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS drm vmwgfx, mediatek, nouveau, amdgpu, rockchip, intel fixes 2018-12-14 09:12:02 -08:00
Makefile Linux 4.20-rc7 2018-12-16 15:46:55 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.