linux-stable.git/arch/parisc, branch linux-6.8.y Linux kernel stable tree parisc: add missing export of __cmpxchg_u8() 2024-05-30T07:48:57+00:00 Al Viro viro@zeniv.linux.org.uk 2024-04-02T02:35:54+00:00 4685dee59c3a1b02ac82c21291d3c71bfbe31b26 [ Upstream commit c57e5dccb06decf3cb6c272ab138c033727149b5 ] __cmpxchg_u8() had been added (initially) for the sake of drivers/phy/ti/phy-tusb1210.c; the thing is, that drivers is modular, so we need an export Fixes: b344d6a83d01 "parisc: add support for cmpxchg on u8 pointers" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c57e5dccb06decf3cb6c272ab138c033727149b5 ]

__cmpxchg_u8() had been added (initially) for the sake of
drivers/phy/ti/phy-tusb1210.c; the thing is, that drivers is
modular, so we need an export

Fixes: b344d6a83d01 "parisc: add support for cmpxchg on u8 pointers"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
prctl: generalize PR_SET_MDWE support check to be per-arch 2024-04-03T13:32:37+00:00 Zev Weiss zev@bewilderbeest.net 2024-02-27T01:35:41+00:00 9699d986251d9845d7fb60dff75e2c741685d96e commit d5aad4c2ca057e760a92a9a7d65bd38d72963f27 upstream. Patch series "ARM: prctl: Reject PR_SET_MDWE where not supported". I noticed after a recent kernel update that my ARM926 system started segfaulting on any execve() after calling prctl(PR_SET_MDWE). After some investigation it appears that ARMv5 is incapable of providing the appropriate protections for MDWE, since any readable memory is also implicitly executable. The prctl_set_mdwe() function already had some special-case logic added disabling it on PARISC (commit 793838138c15, "prctl: Disable prctl(PR_SET_MDWE) on parisc"); this patch series (1) generalizes that check to use an arch_*() function, and (2) adds a corresponding override for ARM to disable MDWE on pre-ARMv6 CPUs. With the series applied, prctl(PR_SET_MDWE) is rejected on ARMv5 and subsequent execve() calls (as well as mmap(PROT_READ|PROT_WRITE)) can succeed instead of unconditionally failing; on ARMv6 the prctl works as it did previously. [0] https://lore.kernel.org/all/2023112456-linked-nape-bf19@gregkh/ This patch (of 2): There exist systems other than PARISC where MDWE may not be feasible to support; rather than cluttering up the generic code with additional arch-specific logic let's add a generic function for checking MDWE support and allow each arch to override it as needed. Link: https://lkml.kernel.org/r/20240227013546.15769-4-zev@bewilderbeest.net Link: https://lkml.kernel.org/r/20240227013546.15769-5-zev@bewilderbeest.net Signed-off-by: Zev Weiss <zev@bewilderbeest.net> Acked-by: Helge Deller <deller@gmx.de> [parisc] Cc: Borislav Petkov <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: Florent Revest <revest@chromium.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Kees Cook <keescook@chromium.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sam James <sam@gentoo.org> Cc: Stefan Roesch <shr@devkernel.io> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: <stable@vger.kernel.org> [6.3+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d5aad4c2ca057e760a92a9a7d65bd38d72963f27 upstream.

Patch series "ARM: prctl: Reject PR_SET_MDWE where not supported".

I noticed after a recent kernel update that my ARM926 system started
segfaulting on any execve() after calling prctl(PR_SET_MDWE).  After some
investigation it appears that ARMv5 is incapable of providing the
appropriate protections for MDWE, since any readable memory is also
implicitly executable.

The prctl_set_mdwe() function already had some special-case logic added
disabling it on PARISC (commit 793838138c15, "prctl: Disable
prctl(PR_SET_MDWE) on parisc"); this patch series (1) generalizes that
check to use an arch_*() function, and (2) adds a corresponding override
for ARM to disable MDWE on pre-ARMv6 CPUs.

With the series applied, prctl(PR_SET_MDWE) is rejected on ARMv5 and
subsequent execve() calls (as well as mmap(PROT_READ|PROT_WRITE)) can
succeed instead of unconditionally failing; on ARMv6 the prctl works as it
did previously.

[0] https://lore.kernel.org/all/2023112456-linked-nape-bf19@gregkh/


This patch (of 2):

There exist systems other than PARISC where MDWE may not be feasible to
support; rather than cluttering up the generic code with additional
arch-specific logic let's add a generic function for checking MDWE support
and allow each arch to override it as needed.

Link: https://lkml.kernel.org/r/20240227013546.15769-4-zev@bewilderbeest.net
Link: https://lkml.kernel.org/r/20240227013546.15769-5-zev@bewilderbeest.net
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Acked-by: Helge Deller <deller@gmx.de>	[parisc]
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Florent Revest <revest@chromium.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Sam James <sam@gentoo.org>
Cc: Stefan Roesch <shr@devkernel.io>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: <stable@vger.kernel.org>	[6.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parisc: Strip upper 32 bit of sum in csum_ipv6_magic for 64-bit builds 2024-04-03T13:32:08+00:00 Guenter Roeck linux@roeck-us.net 2024-02-27T20:33:51+00:00 a8bac29efef06603d7913a48fb5e3e788e47f7fb [ Upstream commit 0568b6f0d863643db2edcc7be31165740c89fa82 ] IPv6 checksum tests with unaligned addresses on 64-bit builds result in unexpected failures. Expected expected == csum_result, but expected == 46591 (0xb5ff) csum_result == 46381 (0xb52d) with alignment offset 1 Oddly enough, the problem disappeared after adding test code into the beginning of csum_ipv6_magic(). As it turns out, the 'sum' parameter of csum_ipv6_magic() is declared as __wsum, which is a 32-bit variable. However, it is treated as 64-bit variable in the 64-bit assembler code. Tests showed that the upper 32 bit of the register used to pass the variable are _not_ cleared when entering the function. This can result in checksum calculation errors. Clearing the upper 32 bit of 'sum' as first operation in the assembler code fixes the problem. Acked-by: Helge Deller <deller@gmx.de> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0568b6f0d863643db2edcc7be31165740c89fa82 ]

IPv6 checksum tests with unaligned addresses on 64-bit builds result
in unexpected failures.

Expected expected == csum_result, but
    expected == 46591 (0xb5ff)
    csum_result == 46381 (0xb52d)
with alignment offset 1

Oddly enough, the problem disappeared after adding test code into
the beginning of csum_ipv6_magic().

As it turns out, the 'sum' parameter of csum_ipv6_magic() is declared as
__wsum, which is a 32-bit variable. However, it is treated as 64-bit
variable in the 64-bit assembler code. Tests showed that the upper 32 bit
of the register used to pass the variable are _not_ cleared when entering
the function. This can result in checksum calculation errors.

Clearing the upper 32 bit of 'sum' as first operation in the assembler
code fixes the problem.

Acked-by: Helge Deller <deller@gmx.de>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
parisc: Fix csum_ipv6_magic on 64-bit systems 2024-04-03T13:32:08+00:00 Guenter Roeck linux@roeck-us.net 2024-02-13T23:46:31+00:00 51de72136b602fc836481e3f91de6a64fbd1effe [ Upstream commit 4b75b12d70506e31fc02356bbca60f8d5ca012d0 ] hppa 64-bit systems calculates the IPv6 checksum using 64-bit add operations. The last add folds protocol and length fields into the 64-bit result. While unlikely, this operation can overflow. The overflow can be triggered with a code sequence such as the following. /* try to trigger massive overflows */ memset(tmp_buf, 0xff, sizeof(struct in6_addr)); csum_result = csum_ipv6_magic((struct in6_addr *)tmp_buf, (struct in6_addr *)tmp_buf, 0xffff, 0xff, 0xffffffff); Fix the problem by adding any overflows from the final add operation into the calculated checksum. Fortunately, we can do this without additional cost by replacing the add operation used to fold the checksum into 32 bit with "add,dc" to add in the missing carry. Cc: Palmer Dabbelt <palmer@rivosinc.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4b75b12d70506e31fc02356bbca60f8d5ca012d0 ]

hppa 64-bit systems calculates the IPv6 checksum using 64-bit add
operations. The last add folds protocol and length fields into the 64-bit
result. While unlikely, this operation can overflow. The overflow can be
triggered with a code sequence such as the following.

	/* try to trigger massive overflows */
	memset(tmp_buf, 0xff, sizeof(struct in6_addr));
	csum_result = csum_ipv6_magic((struct in6_addr *)tmp_buf,
				      (struct in6_addr *)tmp_buf,
				      0xffff, 0xff, 0xffffffff);

Fix the problem by adding any overflows from the final add operation into
the calculated checksum. Fortunately, we can do this without additional
cost by replacing the add operation used to fold the checksum into 32 bit
with "add,dc" to add in the missing carry.

Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
parisc: Fix csum_ipv6_magic on 32-bit systems 2024-04-03T13:32:08+00:00 Guenter Roeck linux@roeck-us.net 2024-02-10T19:15:56+00:00 44f21d397495d607cd87f95f603ea454f834bd47 [ Upstream commit 4408ba75e4ba80c91fde7e10bccccf388f5c09be ] Calculating the IPv6 checksum on 32-bit systems missed overflows when adding the proto+len fields into the checksum. This results in the following unit test failure. # test_csum_ipv6_magic: ASSERTION FAILED at lib/checksum_kunit.c:506 Expected ( u64)csum_result == ( u64)expected, but ( u64)csum_result == 46722 (0xb682) ( u64)expected == 46721 (0xb681) not ok 5 test_csum_ipv6_magic This is probably rarely seen in the real world because proto+len are usually small values which will rarely result in overflows when calculating the checksum. However, the unit test code uses large values for the length field, causing the test to fail. Fix the problem by adding the missing carry into the final checksum. Cc: Palmer Dabbelt <palmer@rivosinc.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4408ba75e4ba80c91fde7e10bccccf388f5c09be ]

Calculating the IPv6 checksum on 32-bit systems missed overflows when
adding the proto+len fields into the checksum. This results in the
following unit test failure.

    # test_csum_ipv6_magic: ASSERTION FAILED at lib/checksum_kunit.c:506
    Expected ( u64)csum_result == ( u64)expected, but
        ( u64)csum_result == 46722 (0xb682)
        ( u64)expected == 46721 (0xb681)
    not ok 5 test_csum_ipv6_magic

This is probably rarely seen in the real world because proto+len are
usually small values which will rarely result in overflows when calculating
the checksum. However, the unit test code uses large values for the length
field, causing the test to fail.

Fix the problem by adding the missing carry into the final checksum.

Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
parisc: Fix ip_fast_csum 2024-04-03T13:32:08+00:00 Guenter Roeck linux@roeck-us.net 2024-02-10T17:55:26+00:00 b7ae1fa5c099b747b784566fe519c3f7ec4f74ca [ Upstream commit a2abae8f0b638c31bb9799d9dd847306e0d005bd ] IP checksum unit tests report the following error when run on hppa/hppa64. # test_ip_fast_csum: ASSERTION FAILED at lib/checksum_kunit.c:463 Expected ( u64)csum_result == ( u64)expected, but ( u64)csum_result == 33754 (0x83da) ( u64)expected == 10946 (0x2ac2) not ok 4 test_ip_fast_csum 0x83da is the expected result if the IP header length is 20 bytes. 0x2ac2 is the expected result if the IP header length is 24 bytes. The test fails with an IP header length of 24 bytes. It appears that ip_fast_csum() always returns the checksum for a 20-byte header, no matter how long the header actually is. Code analysis shows a suspicious assembler sequence in ip_fast_csum(). " addc %0, %3, %0\n" "1: ldws,ma 4(%1), %3\n" " addib,< 0, %2, 1b\n" <--- While my understanding of HPPA assembler is limited, it does not seem to make much sense to subtract 0 from a register and to expect the result to ever be negative. Subtracting 1 from the length parameter makes more sense. On top of that, the operation should be repeated if and only if the result is still > 0, so change the suspicious instruction to " addib,> -1, %2, 1b\n" The IP checksum unit test passes after this change. Cc: Palmer Dabbelt <palmer@rivosinc.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a2abae8f0b638c31bb9799d9dd847306e0d005bd ]

IP checksum unit tests report the following error when run on hppa/hppa64.

    # test_ip_fast_csum: ASSERTION FAILED at lib/checksum_kunit.c:463
    Expected ( u64)csum_result == ( u64)expected, but
        ( u64)csum_result == 33754 (0x83da)
        ( u64)expected == 10946 (0x2ac2)
    not ok 4 test_ip_fast_csum

0x83da is the expected result if the IP header length is 20 bytes. 0x2ac2
is the expected result if the IP header length is 24 bytes. The test fails
with an IP header length of 24 bytes. It appears that ip_fast_csum()
always returns the checksum for a 20-byte header, no matter how long
the header actually is.

Code analysis shows a suspicious assembler sequence in ip_fast_csum().

 "      addc            %0, %3, %0\n"
 "1:    ldws,ma         4(%1), %3\n"
 "      addib,<         0, %2, 1b\n"	<---

While my understanding of HPPA assembler is limited, it does not seem
to make much sense to subtract 0 from a register and to expect the result
to ever be negative. Subtracting 1 from the length parameter makes more
sense. On top of that, the operation should be repeated if and only if
the result is still > 0, so change the suspicious instruction to
 "      addib,>         -1, %2, 1b\n"

The IP checksum unit test passes after this change.

Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
parisc: Avoid clobbering the C/B bits in the PSW with tophys and tovirt macros 2024-04-03T13:32:07+00:00 John David Anglin dave.anglin@bell.net 2024-02-23T15:40:51+00:00 faa60ecd28006a572f09ca186fe6f8142cb6fd51 [ Upstream commit 4603fbaa76b5e703b38ac8cc718102834eb6e330 ] Use add,l to avoid clobbering the C/B bits in the PSW. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4603fbaa76b5e703b38ac8cc718102834eb6e330 ]

Use add,l to avoid clobbering the C/B bits in the PSW.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Sasha Levin <sashal@kernel.org>
parisc/unaligned: Rewrite 64-bit inline assembly of emulate_ldd() 2024-04-03T13:32:07+00:00 Guenter Roeck linux@roeck-us.net 2024-02-16T13:26:55+00:00 24498ddb4d09131483adf213b0be4258567ca064 [ Upstream commit e5db6a74571a8baf87a116ea39aab946283362ff ] Convert to use real temp variables instead of clobbering processor registers. This aligns the 64-bit inline assembly code with the 32-bit assembly code which was rewritten with commit 427c1073a2a1 ("parisc/unaligned: Rewrite 32-bit inline assembly of emulate_ldd()"). While at it, fix comment in 32-bit rewrite code. Temporary variables are now used for both 32-bit and 64-bit code, so move their declarations to the function header. No functional change intended. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e5db6a74571a8baf87a116ea39aab946283362ff ]

Convert to use real temp variables instead of clobbering processor
registers. This aligns the 64-bit inline assembly code with the 32-bit
assembly code which was rewritten with commit 427c1073a2a1
("parisc/unaligned: Rewrite 32-bit inline assembly of emulate_ldd()").

While at it, fix comment in 32-bit rewrite code. Temporary variables are
now used for both 32-bit and 64-bit code, so move their declarations
to the function header.

No functional change intended.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # v6.0+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge tag 'parisc-for-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2024-02-23T18:40:20+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-02-23T18:40:20+00:00 603c04e27c3e9891ce7afa5cd6b496bfacff4206 Pull parisc architecture fixes from Helge Deller: "Fixes CPU hotplug, the parisc stack unwinder and two possible build errors in kprobes and ftrace area: - Fix CPU hotplug - Fix unaligned accesses and faults in stack unwinder - Fix potential build errors by always including asm-generic/kprobes.h - Fix build bug by add missing CONFIG_DYNAMIC_FTRACE check" * tag 'parisc-for-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix stack unwinder parisc/kprobes: always include asm-generic/kprobes.h parisc/ftrace: add missing CONFIG_DYNAMIC_FTRACE check Revert "parisc: Only list existing CPUs in cpu_possible_mask" 
Pull parisc architecture fixes from Helge Deller:
 "Fixes CPU hotplug, the parisc stack unwinder and two possible build
  errors in kprobes and ftrace area:

   - Fix CPU hotplug

   - Fix unaligned accesses and faults in stack unwinder

   - Fix potential build errors by always including asm-generic/kprobes.h

   - Fix build bug by add missing CONFIG_DYNAMIC_FTRACE check"

* tag 'parisc-for-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix stack unwinder
  parisc/kprobes: always include asm-generic/kprobes.h
  parisc/ftrace: add missing CONFIG_DYNAMIC_FTRACE check
  Revert "parisc: Only list existing CPUs in cpu_possible_mask"
parisc: Fix stack unwinder 2024-02-19T20:55:22+00:00 Guenter Roeck linux@roeck-us.net 2024-02-15T21:51:45+00:00 882a2a724ee964c1ebe7268a91d5c8c8ddc796bf Debugging shows a large number of unaligned access traps in the unwinder code. Code analysis reveals a number of issues with this code: - handle_interruption is passed twice through dereference_kernel_function_descriptor() - ret_from_kernel_thread, syscall_exit, intr_return, _switch_to_ret, and _call_on_stack are passed through dereference_kernel_function_descriptor() even though they are not declared as function pointers. To fix the problems, drop one of the calls to dereference_kernel_function_descriptor() for handle_interruption, and compare the other pointers directly. Fixes: 6414b30b39f9 ("parisc: unwind: Avoid missing prototype warning for handle_interruption()") Fixes: 8e0ba125c2bf ("parisc/unwind: fix unwinder when CONFIG_64BIT is enabled") Cc: Helge Deller <deller@gmx.de> Cc: Sven Schnelle <svens@stackframe.org> Cc: John David Anglin <dave.anglin@bell.net> Cc: Charlie Jenkins <charlie@rivosinc.com> Cc: David Laight <David.Laight@ACULAB.COM> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Helge Deller <deller@gmx.de> 
Debugging shows a large number of unaligned access traps in the unwinder
code. Code analysis reveals a number of issues with this code:

- handle_interruption is passed twice through
  dereference_kernel_function_descriptor()
- ret_from_kernel_thread, syscall_exit, intr_return,
  _switch_to_ret, and _call_on_stack are passed through
  dereference_kernel_function_descriptor() even though they are
  not declared as function pointers.

To fix the problems, drop one of the calls to
dereference_kernel_function_descriptor() for handle_interruption,
and compare the other pointers directly.

Fixes: 6414b30b39f9 ("parisc: unwind: Avoid missing prototype warning for handle_interruption()")
Fixes: 8e0ba125c2bf ("parisc/unwind: fix unwinder when CONFIG_64BIT is enabled")
Cc: Helge Deller <deller@gmx.de>
Cc: Sven Schnelle <svens@stackframe.org>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>