linux-stable.git/arch/parisc/kernel/syscall.S, branch linux-5.4.y

parisc: Fix 64-bit userspace syscall path

2024-11-08T15:20:40+00:00

commit d24449864da5838936669618356b0e30ca2999c3 upstream.

Currently the glibc isn't yet ported to 64-bit for hppa, so
there is no usable userspace available yet.
But it's possible to manually build a static 64-bit binary
and run that for testing. One such 64-bit test program is
available at http://ftp.parisc-linux.org/src/64bit.tar.gz
and it shows various issues with the existing 64-bit syscall
path in the kernel.
This patch fixes those issues.

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org      # v4.19+
Signed-off-by: Greg Kroah-Hartman

parisc: Correct completer in lws start

2021-12-29T11:23:36+00:00

commit 8f66fce0f46560b9e910787ff7ad0974441c4f9c upstream.

The completer in the "or,ev %r1,%r30,%r30" instruction is reversed, so we are
not clipping the LWS number when we are called from a 32-bit process (W=0).
We need to nulify the following depdi instruction when the least-significant
bit of %r30 is 1.

If the %r20 register is not clipped, a user process could perform a LWS call
that would branch to an undefined location in the kernel and potentially crash
the machine.

Signed-off-by: John David Anglin 
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Revert "Release spinlocks using ordered store""

2020-08-19T06:16:26+00:00

commit 157e9afcc4fa25068b0e8743bc254a9b56010e13 upstream.

This reverts commit 86d4d068df573a8c2105554624796c086d6bec3d.

Signed-off-by: Helge Deller 
Cc:  # v5.0+
Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Use ldcw instruction for SMP spinlock release barrier"

2020-08-19T06:16:26+00:00

commit 6e9f06ee6c9566f3606d93182ac8f803a148504b upstream.

This reverts commit 9e5c602186a692a7e848c0da17aed40f49d30519.
No need to use the ldcw instruction as SMP spinlock release barrier.
Revert it to gain back speed again.

Signed-off-by: Helge Deller 
Cc:  # v5.2+
Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Drop LDCW barrier in CAS code when running UP"

2020-08-19T06:16:26+00:00

commit 462fb756c7de1ffe5bc6099149136031c2d9c02a upstream.

This reverts commit e6eb5fe9123f05dcbf339ae5c0b6d32fcc0685d5.
We need to optimize it differently. A follow up patch will correct it.

Signed-off-by: Helge Deller 
Cc:  # v5.2+
Signed-off-by: Greg Kroah-Hartman

parisc: Drop LDCW barrier in CAS code when running UP

2019-05-10T19:00:24+00:00

When running an SMP kernel on a single-CPU machine, we can speed up the
CAS code by replacing the LDCW sync barrier with NOP.

Signed-off-by: Helge Deller

parisc: Rename LEVEL to PA_ASM_LEVEL to avoid name clash with DRBD code

2019-05-05T22:09:56+00:00

LEVEL is a very common word, and now after many years it suddenly
clashed with another LEVEL define in the DRBD code.
Rename it to PA_ASM_LEVEL instead.

Reported-by: kbuild test robot 
Signed-off-by: Helge Deller 
Cc:

parisc: Use ldcw instruction for SMP spinlock release barrier

2019-05-03T21:47:40+00:00

There are only a couple of instructions that can function as a memory
barrier on parisc.  Currently, we use the sync instruction as a memory
barrier when releasing a spinlock.  However, the ldcw instruction is a
better barrier when we have a handy memory location since it operates in
the cache on coherent machines.

This patch updates the spinlock release code to use ldcw.  I also
changed the "stw,ma" instructions to "stw" instructions as it is not an
adequate barrier.

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

parisc: generate uapi header and system call table files

2018-12-10T07:26:04+00:00

System call table generation script must be run to gener-
ate unistd_32/64.h and syscall_table_32/64/c32.h files.
This patch will have changes which will invokes the script.

This patch will generate unistd_32/64.h and syscall_table-
_32/64/c32.h files by the syscall table generation script
invoked by parisc/Makefile and the generated files against
the removed files must be identical.

The generated uapi header file will be included in uapi/-
asm/unistd.h and generated system call table header file
will be included by kernel/syscall.S file.

Signed-off-by: Firoz Khan 
Acked-by: Helge Deller 
Signed-off-by: Helge Deller

parisc: Revert "Release spinlocks using ordered store"

2018-11-06T11:03:22+00:00

This reverts commit d27dfa13b9f77ae7e6ed09d70a0426ed26c1a8f9.

Unfortunately, this patch needs to be reverted.  We need the full sync
barrier and not the limited barrier provided by using an ordered store.
The sync ensures that all accesses and cache purge instructions that
follow the sync are performed after all such instructions prior the sync
instruction have completed executing.

The patch breaks the rwlock implementation in glibc.  This caused the
test-lock application in the libprelude testsuite to hang.  With the
change reverted, the test runs correctly and the libprelude package
builds successfully.

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