linux-stable.git/arch/parisc/kernel, branch linux-4.9.y

parisc: Add runtime check to prevent PA2.0 kernels on PA1.x machines

2022-09-15T10:39:45+00:00

[ Upstream commit 591d2108f3abc4db9f9073cae37cf3591fd250d6 ]

If a 32-bit kernel was compiled for PA2.0 CPUs, it won't be able to run
on machines with PA1.x CPUs. Add a check and bail out early if a PA1.x
machine is detected.

Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin

parisc: Fix exception handler for fldw and fstw instructions

2022-09-05T08:23:54+00:00

commit 7ae1f5508d9a33fd58ed3059bd2d569961e3b8bd upstream.

The exception handler is broken for unaligned memory acceses with fldw
and fstw instructions, because it trashes or uses randomly some other
floating point register than the one specified in the instruction word
on loads and stores.

The instruction "fldw 0(addr),%fr22L" (and the other fldw/fstw
instructions) encode the target register (%fr22) in the rightmost 5 bits
of the instruction word. The 7th rightmost bit of the instruction word
defines if the left or right half of %fr22 should be used.

While processing unaligned address accesses, the FR3() define is used to
extract the offset into the local floating-point register set.  But the
calculation in FR3() was buggy, so that for example instead of %fr22,
register %fr12 [((22 * 2) & 0x1f) = 12] was used.

This bug has been since forever in the parisc kernel and I wonder why it
wasn't detected earlier. Interestingly I noticed this bug just because
the libime debian package failed to build on *native* hardware, while it
successfully built in qemu.

This patch corrects the bitshift and masking calculation in FR3().

Signed-off-by: Helge Deller 
Cc: 
Signed-off-by: Greg Kroah-Hartman

parisc: Fix device names in /proc/iomem

2022-08-25T09:09:24+00:00

commit cab56b51ec0e69128909cef4650e1907248d821b upstream.

Fix the output of /proc/iomem to show the real hardware device name
including the pa_pathname, e.g. "Merlin 160 Core Centronics [8:16:0]".
Up to now only the pa_pathname ("[8:16.0]") was shown.

Signed-off-by: Helge Deller 
Cc:  # v4.9+
Signed-off-by: Greg Kroah-Hartman

parisc: Merge model and model name into one line in /proc/cpuinfo

2022-05-12T10:14:56+00:00

commit 5b89966bc96a06f6ad65f64ae4b0461918fcc9d3 upstream.

The Linux tool "lscpu" shows the double amount of CPUs if we have
"model" and "model name" in two different lines in /proc/cpuinfo.
This change combines the model and the model name into one line.

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

parisc/unaligned: Fix ldw() and stw() unalignment handlers

2022-03-02T10:32:00+00:00

commit a97279836867b1cb50a3d4f0b1bf60e0abe6d46c upstream.

Fix 3 bugs:

a) emulate_stw() doesn't return the error code value, so faulting
instructions are not reported and aborted.

b) Tell emulate_ldw() to handle fldw_l as floating point instruction

c) Tell emulate_ldw() to handle ldw_m as integer instruction

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

parisc/unaligned: Fix fldd and fstd unaligned handlers on 32-bit kernel

2022-03-02T10:32:00+00:00

commit dd2288f4a020d693360e3e8d72f8b9d9c25f5ef6 upstream.

Usually the kernel provides fixup routines to emulate the fldd and fstd
floating-point instructions if they load or store 8-byte from/to a not
natuarally aligned memory location.

On a 32-bit kernel I noticed that those unaligned handlers didn't worked and
instead the application got a SEGV.
While checking the code I found two problems:

First, the OPCODE_FLDD_L and OPCODE_FSTD_L cases were ifdef'ed out by the
CONFIG_PA20 option, and as such those weren't built on a pure 32-bit kernel.
This is now fixed by moving the CONFIG_PA20 #ifdef to prevent the compilation
of OPCODE_LDD_L and OPCODE_FSTD_L only, and handling the fldd and fstd
instructions.

The second problem are two bugs in the 32-bit inline assembly code, where the
wrong registers where used. The calculation of the natural alignment used %2
(vall) instead of %3 (ior), and the first word was stored back to address %1
(valh) instead of %3 (ior).

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

parisc: Avoid calling faulthandler_disabled() twice

2022-01-27T07:47:39+00:00

[ Upstream commit 9e9d4b460f23bab61672eae397417d03917d116c ]

In handle_interruption(), we call faulthandler_disabled() to check whether the
fault handler is not disabled. If the fault handler is disabled, we immediately
call do_page_fault(). It then calls faulthandler_disabled(). If disabled,
do_page_fault() attempts to fixup the exception by jumping to no_context:

no_context:

        if (!user_mode(regs) && fixup_exception(regs)) {
                return;
        }

        parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);

Apart from the error messages, the two blocks of code perform the same
function.

We can avoid two calls to faulthandler_disabled() by a simple revision
to the code in handle_interruption().

Note: I didn't try to fix the formatting of this code block.

Signed-off-by: John David Anglin 
Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin

parisc/entry: fix trace test in syscall exit path

2021-11-26T10:48:40+00:00

commit 3ec18fc7831e7d79e2d536dd1f3bc0d3ba425e8a upstream.

commit 8779e05ba8aa ("parisc: Fix ptrace check on syscall return")
fixed testing of TI_FLAGS. This uncovered a bug in the test mask.
syscall_restore_rfi is only used when the kernel needs to exit to
usespace with single or block stepping and the recovery counter
enabled. The test however used _TIF_SYSCALL_TRACE_MASK, which
includes a lot of bits that shouldn't be tested here.

Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly.

I encountered this bug by enabling syscall tracepoints. Both in qemu and
on real hardware. As soon as i enabled the tracepoint (sys_exit_read,
but i guess it doesn't really matter which one), i got random page
faults in userspace almost immediately.

Signed-off-by: Sven Schnelle 
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling

2021-11-26T10:48:32+00:00

[ Upstream commit 66e29fcda1824f0427966fbee2bd2c85bf362c82 ]

With idle polling, IPIs are not sent when a CPU idle, but queued
and run later from do_idle(). The default kgdb_call_nmi_hook()
implementation gets the pointer to struct pt_regs from get_irq_reqs(),
which doesn't work in that case because it was not called from the
IPI interrupt handler. Fix it by defining our own kgdb_roundup()
function which sents an IPI_ENTER_KGDB. When that IPI is received
on the target CPU kgdb_nmicallback() is called.

Signed-off-by: Sven Schnelle 
Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin

parisc: Fix ptrace check on syscall return

2021-11-26T10:48:18+00:00

commit 8779e05ba8aaffec1829872ef9774a71f44f6580 upstream.

The TIF_XXX flags are stored in the flags field in the thread_info
struct (TI_FLAGS), not in the flags field of the task_struct structure
(TASK_FLAGS).

It seems this bug didn't generate any important side-effects, otherwise it
wouldn't have went unnoticed for 12 years (since v2.6.32).

Signed-off-by: Helge Deller 
Fixes: ecd3d4bc06e48 ("parisc: stop using task->ptrace for {single,block}step flags")
Cc: Kyle McMartin 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman