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Message-Id: <20180223165849.16388-1-alexander.sverdlin@nokia.com>
Date: Fri, 23 Feb 2018 17:58:46 +0100
From: Alexander Sverdlin <alexander.sverdlin@...ia.com>
To: Steven Rostedt <rostedt@...dmis.org>,
Ingo Molnar <mingo@...hat.com>,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: Alexander Sverdlin <alexander.sverdlin@...ia.com>,
Russell King <linux@...linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Steven Miao <realmz6@...il.com>,
Tony Luck <tony.luck@...el.com>,
Fenghua Yu <fenghua.yu@...el.com>,
James Hogan <jhogan@...nel.org>,
Michal Simek <monstr@...str.eu>,
Ralf Baechle <ralf@...ux-mips.org>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>,
Martin Schwidefsky <schwidefsky@...ibm.com>,
Heiko Carstens <heiko.carstens@...ibm.com>,
Yoshinori Sato <ysato@...rs.sourceforge.jp>,
Rich Felker <dalias@...c.org>,
"David S. Miller" <davem@...emloft.net>,
Chris Metcalf <cmetcalf@...lanox.com>,
Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
adi-buildroot-devel@...ts.sourceforge.net,
linux-ia64@...r.kernel.org, linux-metag@...r.kernel.org,
linux-mips@...ux-mips.org, linuxppc-dev@...ts.ozlabs.org,
linux-s390@...r.kernel.org, linux-sh@...r.kernel.org,
sparclinux@...r.kernel.org
Subject: [PATCH 0/3] ARM: Implement MODULE_PLT support in FTRACE
FTRACE's function tracer currently doesn't always work on ARM with
MODULE_PLT option enabled. If the module is loaded too far, FTRACE's
code modifier cannot cope with introduced veneers and turns the
function tracer off globally.
ARM64 already has a solution for the problem, refer to the following
patches:
arm64: ftrace: emit ftrace-mod.o contents through code
arm64: module-plts: factor out PLT generation code for ftrace
arm64: ftrace: fix !CONFIG_ARM64_MODULE_PLTS kernels
arm64: ftrace: fix building without CONFIG_MODULES
arm64: ftrace: add support for far branches to dynamic ftrace
arm64: ftrace: don't validate branch via PLT in ftrace_make_nop()
But the presented ARM variant has just a half of the footprint in terms of
the changed LoCs. It also retains the code validation-before-modification
instead of switching it off.
Alexander Sverdlin (3):
ftrace: Add module to ftrace_make_call() parameters
ARM: PLT: Move struct plt_entries definition to header
ftrace: Add MODULE_PLTS support
arch/arm/include/asm/module.h | 10 ++++++
arch/arm/kernel/ftrace.c | 73 ++++++++++++++++++++++++++++++++------
arch/arm/kernel/module-plts.c | 58 +++++++++++++++++++-----------
arch/arm64/kernel/ftrace.c | 3 +-
arch/blackfin/kernel/ftrace.c | 3 +-
arch/ia64/kernel/ftrace.c | 3 +-
arch/metag/kernel/ftrace.c | 3 +-
arch/microblaze/kernel/ftrace.c | 3 +-
arch/mips/kernel/ftrace.c | 3 +-
arch/powerpc/kernel/trace/ftrace.c | 3 +-
arch/s390/kernel/ftrace.c | 3 +-
arch/sh/kernel/ftrace.c | 3 +-
arch/sparc/kernel/ftrace.c | 3 +-
arch/tile/kernel/ftrace.c | 3 +-
arch/x86/kernel/ftrace.c | 3 +-
include/linux/ftrace.h | 4 ++-
kernel/trace/ftrace.c | 6 ++--
17 files changed, 140 insertions(+), 47 deletions(-)
--
2.4.6
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