From: Dave.Martin@arm.com (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 00/10] arm64: Use BRK instruction for generic BUG traps
Date: Mon, 13 Jul 2015 14:25:47 +0100 [thread overview]
Message-ID: <1436793967-7138-1-git-send-email-Dave.Martin@arm.com> (raw)
Changes since v1:
* Modified BRK immediate for BUG so that it doesn't overlap the range
allocated for KGDB.
* Typo fixes.
* Don't assume that BUG() kills the thread, so that catching BUGs in
kgdb works again.
* Separate header for the BRK immediates removed, at Will's request.
I've retained the other refactoring since it contains useful tidy-
ups, but some of that could go away if desired.
Original cover letter:
Currently, the minimal default BUG() implementation from asm-generic is
used for arm64.
This series uses the BRK software breakpoint instruction to generate a
trap instead, similarly to most other arches, with the generic BUG code
generating the dmesg boilerplate. This eliminates a fair amount of
inlined code at BUG() and WARN() sites.
This work makes it look increasingly desirable to collect BRK immediates
together in one place. Patches 1-7 do some refactoring to prepare for
this, and patch 8 moves the definitions to a fresh header, <asm/brk.h>.
Patch 9 provides the BRK-based GENERIC_BUG support for arm64.
A side-effect of this change is that WARNs are now generated via a
different bit of generic code (lib/bug.c:report_bug()) that no longer
prints a backtrace (compare kernel/panic.c:warn_slowpath_common()).) I
will post a separate mini-RFC series to address that in the generic
code. Patch 10 hacks a backtrace back into the arm64 arch code in the
meantime.
Comments and testing welcome.
Quick testing suggests a kernel size reduction of ~110K for arm64
defconfig.
Dave Martin (10):
arm64/debug: Eliminate magic number for size of BRK instruction
arm64/debug: Mask off all reserved bits from generated ESR values
arm64: esr.h type fixes and cleanup
arm64/debug: Eliminate magic number from ESR template definition
arm64/debug: More consistent naming for the BRK ESR template macro
arm64/debug: Move BRK ESR template macro into <asm/esr.h>
arm64/debug: Simplify BRK insn opcode declarations
arm64/debug: Add missing #include
arm64/BUG: Use BRK instruction for generic BUG traps
arm64/BUG: Show explicit backtrace for WARNs
arch/arm64/Kconfig | 8 ++
arch/arm64/include/asm/bug.h | 64 +++++++++++++++
arch/arm64/include/asm/debug-monitors.h | 36 +++------
arch/arm64/include/asm/esr.h | 135 ++++++++++++++++---------------
arch/arm64/include/asm/memory.h | 3 +-
arch/arm64/kernel/kgdb.c | 12 +--
arch/arm64/kernel/traps.c | 61 +++++++++++++-
arch/arm64/mm/fault.c | 12 ++-
8 files changed, 233 insertions(+), 98 deletions(-)
create mode 100644 arch/arm64/include/asm/bug.h
--
1.7.10.4
next reply other threads:[~2015-07-13 13:25 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-13 13:25 Dave Martin [this message]
2015-07-13 13:25 ` [PATCH v2 01/10] arm64/debug: Eliminate magic number for size of BRK instruction Dave Martin
2015-07-13 14:47 ` Mark Rutland
2015-07-13 13:25 ` [PATCH v2 02/10] arm64/debug: Mask off all reserved bits from generated ESR values Dave Martin
2015-07-13 14:14 ` Mark Rutland
2015-07-13 14:22 ` Dave Martin
2015-07-13 13:25 ` [PATCH v2 03/10] arm64: esr.h type fixes and cleanup Dave Martin
2015-07-14 15:54 ` Mark Rutland
2015-07-14 16:53 ` Dave Martin
2015-07-13 13:25 ` [PATCH v2 04/10] arm64/debug: Eliminate magic number from ESR template definition Dave Martin
2015-07-13 14:16 ` Mark Rutland
2015-07-13 13:25 ` [PATCH v2 05/10] arm64/debug: More consistent naming for the BRK ESR template macro Dave Martin
2015-07-13 14:19 ` Mark Rutland
2015-07-13 13:25 ` [PATCH v2 06/10] arm64/debug: Move BRK ESR template macro into <asm/esr.h> Dave Martin
2015-07-13 14:18 ` Mark Rutland
2015-07-13 13:25 ` [PATCH v2 07/10] arm64/debug: Simplify BRK insn opcode declarations Dave Martin
2015-07-13 14:38 ` Mark Rutland
2015-07-13 13:25 ` [PATCH v2 08/10] arm64/debug: Add missing #include Dave Martin
2015-07-13 14:34 ` Mark Rutland
2015-07-13 14:44 ` Dave Martin
2015-07-13 14:45 ` Mark Rutland
2015-07-13 13:25 ` [PATCH v2 09/10] arm64/BUG: Use BRK instruction for generic BUG traps Dave Martin
2015-07-13 16:43 ` Mark Rutland
2015-07-13 16:51 ` Dave Martin
2015-07-13 16:56 ` Mark Rutland
2015-07-13 17:05 ` Dave P Martin
2015-07-14 10:20 ` Dave Martin
2015-07-14 11:09 ` Mark Rutland
2015-07-14 11:34 ` Dave Martin
2015-07-14 15:51 ` Mark Rutland
2015-07-14 16:53 ` Dave Martin
2015-07-14 16:11 ` Catalin Marinas
2015-07-14 16:55 ` Dave Martin
2015-07-13 13:25 ` [PATCH v2 10/10] arm64/BUG: Show explicit backtrace for WARNs Dave Martin
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