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path: root/arch/sh/kernel/hw_breakpoint.c
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2010-05-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (127 commits) sh: update defconfigs. sh: Fix up the NUMA build for recent LMB changes. sh64: provide a stub per_cpu_trap_init() definition. sh: fix up CONFIG_KEXEC=n build. sh: fixup the docbook paths for clock framework shuffling. driver core: Early dev_name() depends on slab_is_available(). sh: simplify WARN usage in SH clock driver sh: Check return value of clk_get on ms7724 sh: Check return value of clk_get on ecovec24 sh: move sh clock-cpg.c contents to drivers/sh/clk-cpg.c sh: move sh clock.c contents to drivers/sh/clk. sh: move sh asm/clock.h contents to linux/sh_clk.h V2 sh: remove unused clock lookup sh: switch boards to clkdev sh: switch sh4-202 to clkdev sh: switch shx3 to clkdev sh: switch sh7757 to clkdev sh: switch sh7763 to clkdev sh: switch sh7780 to clkdev sh: switch sh7786 to clkdev ...
2010-05-01hw-breakpoints: Change/Enforce some breakpoints policiesFrederic Weisbecker
The current policies of breakpoints in x86 and SH are the following: - task bound breakpoints can only break on userspace addresses - cpu wide breakpoints can only break on kernel addresses The former rule prevents ptrace breakpoints to be set to trigger on kernel addresses, which is good. But as a side effect, we can't breakpoint on kernel addresses for task bound breakpoints. The latter rule simply makes no sense, there is no reason why we can't set breakpoints on userspace while performing cpu bound profiles. We want the following new policies: - task bound breakpoint can set userspace address breakpoints, with no particular privilege required. - task bound breakpoints can set kernelspace address breakpoints but must be privileged to do that. - cpu bound breakpoints can do what they want as they are privileged already. To implement these new policies, this patch checks if we are dealing with a kernel address breakpoint, if so and if the exclude_kernel parameter is set, we tell the user that the breakpoint is invalid, which makes a good generic ptrace protection. If we don't have exclude_kernel, ensure the user has the right privileges as kernel breakpoints are quite sensitive (risk of trap recursion attacks and global performance impacts). [ Paul Mundt: keep addr space check for sh signal delivery and fix double function declaration] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: K. Prasad <prasad@linux.vnet.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-04-21sh: hw-breakpoints: Kill off stub unthrottle callback.Paul Mundt
This follows the x86 change and kills off the unthrottle stub. As the x86 change killed off the generic callback it isn't used anymore anyways. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-03-01sh: hw-breakpoints: Accept breakpoints on NULL addresses.Paul Mundt
This follows the x86 change 84d710926797a6e317e7e94654a3ccd771cfd8a3 ("hw-breakpoints: Accept breakpoints on NULL address") and restores the previous expected ptrace behaviour. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-05sh: Abstracted SH-4A UBC support on hw-breakpoint core.Paul Mundt
This is the next big chunk of hw_breakpoint support. This decouples the SH-4A support from the core and moves it out in to its own stub, following many of the conventions established with the perf events layering. In addition to extending SH-4A support to encapsulate the remainder of the UBC channels, clock framework support for handling the UBC interface clock is added as well, allowing for dynamic clock gating. This also fixes up a regression introduced by the SIGTRAP handling that broke the ksym_tracer, to the extent that the current support works well with all of the ksym_tracer/ptrace/kgdb. The kprobes singlestep code will follow in turn. With this in place, the remaining UBC variants (SH-2A and SH-4) can now be trivially plugged in. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-12-28sh: Convert ptrace to hw_breakpoint API.Paul Mundt
This is the initial step for converting singlestep handling via ptrace over to hw_breakpoints. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-12-22sh: Don't NOTIFY_STOP for non-UBC breakpoint traps.Paul Mundt
Presently the hw_breakpoint code is the primary notifier dispatch for breakpoint traps, although it's only UBC traps that are of particular interest there. This patches in a check to allow non-UBC generated breakpoints to pass through down the remainder of the notifier chain, giving things like kgdb a chance at getting notified. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-12-21sh: Fix up hw-breakpoints build for API changes.Paul Mundt
The event callback handling has been removed in favour of going through a generic event handler to handle overflows. Follows the x86 change. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-12-08sh: hw-breakpoints: Add preliminary support for SH-4A UBC.Paul Mundt
This adds preliminary support for the SH-4A UBC to the hw-breakpoints API. Presently only a single channel is implemented, and the ptrace interface still needs to be converted. This is the first step to cleaning up the long-standing UBC mess, making the UBC more generally accessible, and finally making it SMP safe. An additional abstraction will be layered on top of this as with the perf events code to permit the various CPU families to wire up support for their own specific UBCs, as many variations exist. Signed-off-by: Paul Mundt <lethal@linux-sh.org>