BMC/Intel-BMC/linux.git/arch/powerpc/kernel/hw_breakpoint.c, branch dev-5.2

powerpc: silence a -Wcast-function-type warning in dawr_write_file_bool

2019-07-31T05:24:46+00:00

[ Upstream commit 548c54acba5bd1388d50727a9a126a42d0cd4ad0 ] In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") the following piece of code was added: smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); Since GCC 8 this triggers the following warning about incompatible function types: arch/powerpc/kernel/hw_breakpoint.c:408:21: error: cast between incompatible function types from 'int (*)(struct arch_hw_breakpoint *)' to 'void (*)(void *)' [-Werror=cast-function-type] Since the warning is there for a reason, and should not be hidden behind a cast, provide an intermediate callback function to avoid the warning. Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") Suggested-by: Christoph Hellwig Signed-off-by: Mathieu Malaterre Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc: Add force enable of DAWR on P9 option

2019-04-20T12:20:45+00:00

This adds a flag so that the DAWR can be enabled on P9 via: echo Y > /sys/kernel/debug/powerpc/dawr_enable_dangerous The DAWR was previously force disabled on POWER9 in: 9654153158 powerpc: Disable DAWR in the base POWER9 CPU features Also see Documentation/powerpc/DAWR-POWER9.txt This is a dangerous setting, USE AT YOUR OWN RISK. Some users may not care about a bad user crashing their box (ie. single user/desktop systems) and really want the DAWR. This allows them to force enable DAWR. This flag can also be used to disable DAWR access. Once this is cleared, all DAWR access should be cleared immediately and your machine once again safe from crashing. Userspace may get confused by toggling this. If DAWR is force enabled/disabled between getting the number of breakpoints (via PTRACE_GETHWDBGINFO) and setting the breakpoint, userspace will get an inconsistent view of what's available. Similarly for guests. For the DAWR to be enabled in a KVM guest, the DAWR needs to be force enabled in the host AND the guest. For this reason, this won't work on POWERVM as it doesn't allow the HCALL to work. Writes of 'Y' to the dawr_enable_dangerous file will fail if the hypervisor doesn't support writing the DAWR. To double check the DAWR is working, run this kernel selftest: tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c Any errors/failures/skips mean something is wrong. Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman

perf/arch/powerpc: Implement hw_breakpoint_arch_parse()

2018-06-26T07:07:55+00:00

Migrate to the new API in order to remove arch_validate_hwbkpt_settings() that clumsily mixes up architecture validation and commit Signed-off-by: Frederic Weisbecker Acked-by: Michael Ellerman Cc: Alexander Shishkin Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Chris Zankel Cc: Jiri Olsa Cc: Joel Fernandes Cc: Linus Torvalds Cc: Mark Rutland Cc: Max Filippov Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Rich Felker Cc: Thomas Gleixner Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/1529981939-8231-5-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar

perf/hw_breakpoint: Pass arch breakpoint struct to arch_check_bp_in_kernelspace()

2018-06-26T07:07:54+00:00

We can't pass the breakpoint directly on arch_check_bp_in_kernelspace() anymore because its architecture internal datas (struct arch_hw_breakpoint) are not yet filled by the time we call the function, and most implementation need this backend to be up to date. So arrange the function to take the probing struct instead. Signed-off-by: Frederic Weisbecker Cc: Alexander Shishkin Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Chris Zankel Cc: Jiri Olsa Cc: Joel Fernandes Cc: Linus Torvalds Cc: Mark Rutland Cc: Max Filippov Cc: Michael Ellerman Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Rich Felker Cc: Thomas Gleixner Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/1529981939-8231-3-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar

powerpc/ptrace: Fix enforcement of DAWR constraints

2018-05-21T04:47:44+00:00

Back when we first introduced the DAWR, in commit 4ae7ebe9522a ("powerpc: Change hardware breakpoint to allow longer ranges"), we screwed up the constraint making it a 1024 byte boundary rather than a 512. This makes the check overly permissive. Fortunately GDB is the only real user and it always did they right thing, so we never noticed. This fixes the constraint to 512 bytes. Fixes: 4ae7ebe9522a ("powerpc: Change hardware breakpoint to allow longer ranges") Cc: stable@vger.kernel.org # v3.9+ Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman

powerpc: Update ptrace to use ppc_breakpoint_available()

2018-03-27T12:52:44+00:00

This updates the ptrace code to use ppc_breakpoint_available(). We now advertise via PPC_PTRACE_GETHWDBGINFO zero breakpoints when the DAWR is missing (ie. POWER9). This results in GDB falling back to software emulation of the breakpoint (which is slow). For the features advertised by PPC_PTRACE_GETHWDBGINFO, we keep advertising DAWR as if we don't GDB assumes 1 breakpoint irrespective of the number of breakpoints advertised. GDB then fails later when trying to set this one breakpoint. Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into next

2017-02-18T10:37:14+00:00

Freescale updates from Scott: "Highlights include 8xx breakpoints and perf, t1042rdb display support, and board updates."

powerpc/xmon: Fix data-breakpoint

2017-02-15T09:02:25+00:00

Currently xmon data-breakpoint feature is broken. Whenever there is a watchpoint match occurs, hw_breakpoint_handler will be called by do_break via notifier chains mechanism. If watchpoint is registered by xmon, hw_breakpoint_handler won't find any associated perf_event and returns immediately with NOTIFY_STOP. Similarly, do_break also returns without notifying to xmon. Solve this by returning NOTIFY_DONE when hw_breakpoint_handler does not find any perf_event associated with matched watchpoint, rather than NOTIFY_STOP, which tells the core code to continue calling the other breakpoint handlers including the xmon one. Cc: stable@vger.kernel.org Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman

powerpc/8xx: Implement hw_breakpoint

2017-01-25T08:43:59+00:00

This patch implements HW breakpoint on the 8xx. The 8xx has capability to manage HW breakpoints, which is slightly different than BOOK3S: 1/ The breakpoint match doesn't trigger a DSI exception but a dedicated data breakpoint exception. 2/ The breakpoint happens after the instruction has completed, no need to single step or emulate the instruction, 3/ Matched address is not set in DAR but in BAR, 4/ DABR register doesn't exist, instead we have registers LCTRL1, LCTRL2 and CMPx registers, 5/ The match on one comparator is not on a double word but on a single word. The patch does: 1/ Prepare the dedicated registers in call to __set_dabr(). In order to emulate the double word handling of BOOK3S, comparator E is set to DABR address value and comparator F to address + 4. Then breakpoint 1 is set to match comparator E or F, 2/ Skip the singlestepping stage when compiled for CONFIG_PPC_8xx, 3/ Implement the exception. In that exception, the matched address is taken from SPRN_BAR and manage as if it was from SPRN_DAR. 4/ I/D TLB error exception routines perform a tlbie on bad TLBs. That tlbie triggers the breakpoint exception when performed on the breakpoint address. For this reason, the routine returns if the match is from one of those two tlbie. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood