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

parisc: Fix itlb miss handler for 64-bit programs

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

commit 9542130937e9dc707dd7c6b7af73326437da2d50 upstream.

For an itlb miss when executing code above 4 Gb on ILP64 adjust the
iasq/iaoq in the same way isr/ior was adjusted.  This fixes signal
delivery for the 64-bit static test program from
http://ftp.parisc-linux.org/src/64bit.tar.gz.  Note that signals are
handled by the signal trampoline code in the 64-bit VDSO which is mapped
into high userspace memory region above 4GB for 64-bit processes.

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

parisc/pgtable: Do not drop upper 5 address bits of physical address

2023-11-28T16:50:20+00:00

commit 166b0110d1ee53290bd11618df6e3991c117495a upstream.

When calculating the pfn for the iitlbt/idtlbt instruction, do not
drop the upper 5 address bits. This doesn't seem to have an effect
on physical hardware which uses less physical address bits, but in
qemu the missing bits are visible.

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

parisc/entry: fix trace test in syscall exit path

2021-11-21T12:38:50+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: Fix ptrace check on syscall return

2021-11-17T08:48:17+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

parisc: Do not use an ordered store in pa_tlb_lock()

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

commit e72b23dec1da5e62a0090c5da1d926778284e230 upstream.

No need to use an ordered store in pa_tlb_lock() and update the comment
regarng usage of the sid register to unlocak a spinlock in
tlb_unlock0().

Signed-off-by: John David Anglin 
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

parisc: fix frame pointer in ftrace_regs_caller()

2019-10-30T20:24:40+00:00

The current code in ftrace_regs_caller() doesn't assign
%r3 to contain the address of the current frame. This
is hidden if the kernel is compiled with FRAME_POINTER,
but without it just crashes because it tries to dereference
an arbitrary address. Fix this by always setting %r3 to the
current stack frame.

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

parisc/ftrace: Add KPROBES_ON_FTRACE

2019-08-03T06:56:57+00:00

Allow KPROBES to use the ftrace infrastructure on PA-RISC.

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

parisc: Wire up clone3 syscall

2019-07-17T21:11:28+00:00

Signed-off-by: Helge Deller 
Tested-by: Sven Schnelle 
Acked-by: Christian Brauner

parisc: add dynamic ftrace

2019-06-08T10:56:29+00:00

This patch implements dynamic ftrace for PA-RISC. The required mcount
call sequences can get pretty long, so instead of patching the
whole call sequence out of the functions, we are using
-fpatchable-function-entry from gcc. This puts a configurable amount of
NOPS before/at the start of the function. Taking do_sys_open() as example,
which would look like this when the call is patched out:

1036b248:       08 00 02 40     nop
1036b24c:       08 00 02 40     nop
1036b250:       08 00 02 40     nop
1036b254:       08 00 02 40     nop

1036b258 :
1036b258:       08 00 02 40     nop
1036b25c:       08 03 02 41     copy r3,r1
1036b260:       6b c2 3f d9     stw rp,-14(sp)
1036b264:       08 1e 02 43     copy sp,r3
1036b268:       6f c1 01 00     stw,ma r1,80(sp)

When ftrace gets enabled for this function the kernel will patch these
NOPs to:

1036b248:       10 19 57 20     
1036b24c:       6f c1 00 80     stw,ma r1,40(sp)
1036b250:       48 21 3f d1     ldw -18(r1),r1
1036b254:       e8 20 c0 02     bv,n r0(r1)

1036b258 :
1036b258:       e8 3f 1f df     b,l,n .-c,r1
1036b25c:       08 03 02 41     copy r3,r1
1036b260:       6b c2 3f d9     stw rp,-14(sp)
1036b264:       08 1e 02 43     copy sp,r3
1036b268:       6f c1 01 00     stw,ma r1,80(sp)

So the first NOP in do_sys_open() will be patched to jump backwards into
some minimal trampoline code which pushes a stackframe, saves r1 which
holds the return address, loads the address of the real ftrace function,
and branches to that location. For 64 Bit things are getting a bit more
complicated (and longer) because we must make sure that the address of
ftrace location is 8 byte aligned, and the offset passed to ldd for
fetching the address is 8 byte aligned as well.

Note that gcc has a bug which misplaces the function label, and needs a
patch to make dynamic ftrace work. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90751 for details.

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