linux-stable.git/arch/parisc/kernel/entry.S, branch v5.18.2

parisc: Simplify fast path for non-access data TLB faults

2022-03-11T18:49:30+00:00

With the latest cache fix for non-access faults and the support for
non-access faults (code 17) in handle_interruption, we can remove
the fast path emulation for fdc, fic, pdc, lpa, probe and probei
instructions.

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

parisc: Convert PTE lookup to use extru_safe() macro

2021-11-22T06:37:31+00:00

Convert the PTE lookup functions to use the safer extru_safe macro.

Signed-off-by: Helge Deller

parisc/entry: fix trace test in syscall exit path

2021-11-13T21:10:56+00:00

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

parisc: Move thread_info into task struct

2021-11-01T06:35:59+00:00

This implements the CONFIG_THREAD_INFO_IN_TASK option.

With this change:
- before thread_info was part of the stack and located at the beginning of the stack
- now the thread_info struct is moved and located inside the task_struct structure
- the stack is allocated and handled like the major other platforms
- drop the cpu field of thread_info and use instead the one in task_struct

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

parisc: move virt_map macro to assembly.h

2021-11-01T06:35:59+00:00

This macro will also be used by the TOC code, so move it
into asm/assembly.h to avoid duplication.

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

parisc: Fix ptrace check on syscall return

2021-11-01T06:35:58+00:00

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

parisc: Use PRIV_USER instead of 3 in entry.S

2021-10-30T21:11:01+00:00

Signed-off-by: Helge Deller

parisc: fix preempt_count() check in entry.S

2021-10-30T21:11:01+00:00

preempt_count in struct thread_info is unsigned int,
but the entry.S code used LDREG, which generates a 64 bit
load when compiled for 64 bit. Fix this to use an ldw and
also change the condition in the compare one line below
to only compares 32 bits, although ldw zero extends, and
that should work with a 64 bit compare.

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

parisc: Optimize per-pagetable spinlocks

2021-02-12T15:39:42+00:00

On parisc a spinlock is stored in the next page behind the pgd which
protects against parallel accesses to the pgd. That's why one additional
page (PGD_ALLOC_ORDER) is allocated for the pgd.

Matthew Wilcox suggested that we instead should use a pointer in the
struct page table for this spinlock and noted, that the comments for the
PGD_ORDER and PMD_ORDER defines were wrong.

Both suggestions are addressed with this patch. Instead of having an own
spinlock to protect the pgd, we now switch to use the existing
page_table_lock.  Additionally, beside loading the pgd into cr25 in
switch_mm_irqs_off(), the physical address of this lock is loaded into
cr28 (tr4), so that we can avoid implementing a complicated lookup in
assembly for this lock in the TLB fault handlers.

The existing Hybrid L2/L3 page table scheme (where the pmd is adjacent
to the pgd) has been dropped with this patch.

Remove the locking in set_pte() and the huge-page pte functions too.
They trigger a spinlock recursion on 32bit machines and seem unnecessary.

Suggested-by: Matthew Wilcox 
Fixes: b37d1c1898b2 ("parisc: Use per-pagetable spinlock")
Signed-off-by: John David Anglin 
Signed-off-by: Helge Deller

parisc: Enable -mlong-calls gcc option by default when !CONFIG_MODULES

2021-01-26T19:16:21+00:00

When building a kernel without module support, the CONFIG_MLONGCALL option
needs to be enabled in order to reach symbols which are outside of a 22-bit
branch.

This patch changes the autodetection in the Kconfig script to always enable
CONFIG_MLONGCALL when modules are disabled and uses a far call to
preempt_schedule_irq() in intr_do_preempt() to reach the symbol in all cases.

Signed-off-by: Helge Deller 
Reported-by: kernel test robot 
Cc: stable@vger.kernel.org # v5.6+