parisc: Fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Avoid using hardware single-step in kprobes

This patch changes the kprobe and kretprobe feature to use another
break instruction instead of relying on the hardware single-step
feature.
That way those kprobes now work in qemu as well, because in qemu we
don't emulate yet single-stepping.

Signed-off-by: Helge Deller <deller@gmx.de>

kprobes: treewide: Make it harder to refer kretprobe_trampoline directly

Since now there is kretprobe_trampoline_addr() for referring the
address of kretprobe trampoline code, we don't need to access
kretprobe_trampoline directly.

Make it harder to refer by renaming it to __kretprobe_trampoline().

Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()

The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:

dereference_kernel_function_descriptor(kretprobe_trampoline)

In fact we had bugs in arch code where it wasn't replicated correctly.

So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.

Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parisc: kprobes: Use generic kretprobe trampoline handler

Use the generic kretprobe trampoline handler. Don't use
framepointer verification.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870609708.1229682.1861714117180719169.stgit@devnote2

kprobes/parisc: remove arch_kprobe_on_func_entry()

The common kprobes provides a weak implementation of
arch_kprobe_on_func_entry(). The parisc version is the same as the
common version, so remove it.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Avoid kernel panic triggered by invalid kprobe

When running gdb I was able to trigger this kernel panic:

Kernel Fault: Code=26 (Data memory access rights trap) at addr 0000000000000060
CPU: 0 PID: 1401 Comm: gdb-crash Not tainted 5.2.0-rc7-64bit+ #1053

YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001000000000000001111 Not tainted
r00-03 000000000804000f 0000000040dee1a0 0000000040c78cf0 00000000b8d50160
r04-07 0000000040d2b1a0 000000004360a098 00000000bbbe87b8 0000000000000003
r08-11 00000000fac20a70 00000000fac24160 00000000fac1bbe0 0000000000000000
r12-15 00000000fabfb79a 00000000fac244a4 0000000000010000 0000000000000001
r16-19 00000000bbbe87b8 00000000f8f02910 0000000000010034 0000000000000000
r20-23 00000000fac24630 00000000fac24630 000000006474e552 00000000fac1aa52
r24-27 0000000000000028 00000000bbbe87b8 00000000bbbe87b8 0000000040d2b1a0
r28-31 0000000000000000 00000000b8d501c0 00000000b8d501f0 0000000003424000
sr00-03 0000000000423000 0000000000000000 0000000000000000 0000000000423000
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 0000000040c78cf0 0000000040c78cf4
IIR: 539f00c0 ISR: 0000000000000000 IOR: 0000000000000060
CPU: 0 CR30: 00000000b8d50000 CR31: 00000000d22345e2
ORIG_R28: 0000000040250798
IAOQ[0]: parisc_kprobe_ss_handler+0x58/0x170
IAOQ[1]: parisc_kprobe_ss_handler+0x5c/0x170
RP(r2): parisc_kprobe_ss_handler+0x58/0x170
Backtrace:
[<0000000040206ff8>] handle_interruption+0x178/0xbb8
Kernel panic - not syncing: Kernel Fault

Avoid this panic by checking the return value of kprobe_running() and
skip kprobe if none is currently active.

Cc: <stable@vger.kernel.org> # v5.2
Acked-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Implement kretprobes

Implement kretprobes on parisc, parts stolen from powerpc.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Implement kprobes

Implement kprobes support for PA-RISC.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>