Previously tile was rolling its own method of capturing backtrace data
in the NMI handlers, but it was relying on running printk() from the NMI
handler, which is not always safe. So adopt the nmi_backtrace model
(with the new cpumask extension) instead.
So we can call the nmi_backtrace code directly from the nmi handler,
move the nmi_enter()/exit() into the top-level tile NMI handler.
The semantics of the routine change slightly since it is now synchronous
with the remote cores completing the backtraces. Previously it was
asynchronous, but with protection to avoid starting a new remote
backtrace if the old one was still in progress.
Link: http://lkml.kernel.org/r/1472487169-14923-4-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Cc: Petr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This ensures that we always notify context tracking that we
have exited from user space no matter how we enter the kernel.
It is similar to how arm64 handles context tracking, for example.
This allows the removal of all the exception_enter() calls that
were added in commit 49e4e15619 ("tile: support CONTEXT_TRACKING and
thus NOHZ_FULL").
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
This commit fixes a number of issues with the tile backtrace code.
- Don't try to identify userspace shared object or executable paths
if we are doing a backtrace from an interrupt; it's not legal,
and also unlikely to be interesting. Likewise, don't try to do
it for other address spaces, since d_path() assumes it is being
called in "current" context.
- Move "in_backtrace" from thread_struct to thread_info.
This way we can access it even if our stack thread_info has been
clobbered, which makes backtracing more robust.
- Avoid using "current" directly when testing for is_sigreturn().
Since "current" may be corrupt, we're better off using kbt->task
explicitly to look up the vdso_base for the current task.
Conveniently, this simplifies the internal APIs (we only need
one is_sigreturn() function now).
- Avoid bogus "Odd fault" warning when pc/sp/ex1 are all zero,
as is true for kernel threads above the last frame.
- Hook into Tejun Heo's dump_stack() framework in lib/dump_stack.c.
- Write last entry in save_stack_trace() as ULONG_MAX, not zero,
since ftrace (at least) relies on finding that marker.
- Implement save_stack_trace_regs() and save_strack_trace_user(),
and set CONFIG_USER_STACKTRACE_SUPPORT.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
A new hypervisor service was added some time ago (MDE 4.2.1 or
later, or MDE 4.3 or later) that allows cores to request NMIs
to be delivered to other cores. Use this facility to deliver
a request that causes a backtrace to be generated on each core,
and hook it into the magic SysRq functionality.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Add the TIF_NOHZ flag appropriately.
Add call to user_exit() on entry to do_work_pending() and on entry
to syscalls via do_syscall_trace_enter(), and also the top of
do_syscall_trace_exit() just because it's done in x86.
Add call to user_enter() at the bottom of do_work_pending() once we
have no more work to do before returning to userspace.
Wrap all the trap code in exception_enter() / exception_exit().
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
And other message logging neatening.
Other miscellanea:
o coalesce formats
o realign arguments
o standardize a couple of macros
o use __func__ instead of embedding the function name
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
ARRAY_SIZE is more concise to use when the size of an array is divided
by the size of its type or the size of its first element.
The semantic patch that makes this change is as follows:
// <smpl>
@i@
@@
@@
type T;
T[] E;
@@
- (sizeof(E)/sizeof(T))
+ ARRAY_SIZE(E)
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
remove obsolete calls to strict_strto* and replace them
with kstrto* calls accordingly.
Signed-off-by: Daniel Walter <dwalter@google.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Enter kernel debugger at boot with:
--hvd UART_1=1 --hvx kgdbwait --hvx kgdboc=ttyS1,115200
or at runtime with:
echo ttyS1,115200 > /sys/module/kgdboc/parameters/kgdboc
echo g > /proc/sysrq-trigger
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The existing code relied on the hardware definition (<arch/chip.h>)
to specify how much VA and PA space was available. It's convenient
to allow customizing this for some configurations, so provide symbols
MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified
if desired.
Additionally, move away from the MEM_XX_INTRPT nomenclature to
define the start of various regions within the VA space. In fact
the cleaner symbol is, for example, MEM_SV_START, to indicate the
start of the area used for supervisor code; the actual address of the
interrupt vectors is not as important, and can be changed if desired.
As part of this change, convert from "intrpt1" nomenclature (which
built in the old privilege-level 1 model) to a simple "intrpt".
Also strip out some tilepro-specific code supporting modifying the
PL the kernel could run at, since we don't actually support using
different PLs in tilepro, only tilegx.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change includes support for Kprobes, Jprobes and Return Probes.
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Tony Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
First, don't re-enable interrupts blindly in the Linux trap handler.
We already handle page faults this way; synchronous interrupts like
ILL_TRANS will fire even when interrupts are disabled, and we don't
want to re-enable interrupts in that case.
For ILL_TRANS, we now pass the ILL_VA_PC reason into the trap handler
so we can report it properly; this is the address that caused the
illegal translation trap. We print the address as part of the
pr_alert() message now if it's coming from the kernel.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
If the kernel unexpectedly takes a bad trap, it's convenient to
have it report the type of trap as part of the error. This gives
customers a bit more context before they call up customer support.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We now respond to MEM_ERROR traps (e.g. an atomic instruction to
non-cacheable memory) with a SIGBUS.
We also no longer generate a console crash message if a user
process die due to a SIGTRAP.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
In certain circumstances we need to do a bunch of jump-and-link
instructions to fill the hardware return-address stack with nonzero values.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The kernel code was using some <asm> headers that included a mix
of hardware-specific information (typically found in Tilera <arch>
headers) and structures, enums, and function declarations supporting
the disassembly function of the tile-desc.c sources.
This change refactors that code so that a hardware-specific, but
OS- and application-agnostic header, is created: <arch/opcode.h>.
This header is then exported to userspace along with the other
<arch> headers and can be used to build userspace code; in particular,
it is used by glibc as part of implementing the backtrace() function.
The new header, together with a header that specifically describes
the disassembly code (<asm/tile-desc.h> with _32 and _64 variants),
replaces the old <asm/opcode-tile*.h> and <asm/opcode_constants*.h>
headers.
As part of this change, we are also renaming the 32-bit constants
from TILE_xxx to TILEPRO_xxx to better reflect the fact that they
are specific to the TILEPro architecture, and not to TILE-Gx
and any successor "tile" architecture chips.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This change adds support for /proc/sys/debug/exception-trace to tile.
Like x86 and sparc, by default it is set to "1", generating a one-line
printk whenever a user process crashes. By setting it to "2", we get
a much more complete userspace diagnostic at crash time, including
a user-space backtrace, register dump, and memory dump around the
address of the crash.
Some vestiges of the Tilera-internal version of this support are
removed with this patch (the show_crashinfo variable and the
arch_coredump_signal function). We retain a "crashinfo" boot parameter
which allows you to set the boot-time value of exception-trace.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This is not quite the complete support, since we're not yet shipping
intvec_64.S, but it is the support relevant to the set of files we are
currently shipping, and makes it easier to track changes between
our internal sources and our public GIT repository.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
While not a port to KVM (yet), this change modifies the kernel
to be able to build either at PL1 or at PL2 with a suitable
config switch. Pushing up this change avoids handling branch
merge issues going forward with the KVM work.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This functionality was stubbed out until recently. Now we support our
normal backtracing API on TILE-Gx as well as on TILE64/TILEPro.
This change includes a tweak to the instruction encoding caused by
adding addxli for compat mode.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is primarily changes caused by reviewing "sparse"
and "checkpatch" output on our sources, so is somewhat noisy, since
things like "printk() -> pr_err()" (or whatever) throughout the
codebase tend to get tedious to read. Rather than trying to tease
apart precisely which things changed due to which type of code
review, this commit includes various cleanups in the code:
- sparse: Add declarations in headers for globals.
- sparse: Fix __user annotations.
- sparse: Using gfp_t consistently instead of int.
- sparse: removing functions not actually used.
- checkpatch: Clean up printk() warnings by using pr_info(), etc.;
also avoid partial-line printks except in bootup code.
- checkpatch: Use exposed structs rather than typedefs.
- checkpatch: Change some C99 comments to C89 comments.
In addition, a couple of minor other changes are rolled in
to this commit:
- Add support for a "raise" instruction to cause SIGFPE, etc., to be raised.
- Remove some compat code that is unnecessary when we fully eliminate
some of the deprecated syscalls from the generic syscall ABI.
- Update the tile_defconfig to reflect current config contents.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.
This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>
