linux-stable.git/arch/sparc, branch linux-5.4.y

sparc/module: Add R_SPARC_UA64 relocation handling

2025-12-03T11:45:13+00:00

[ Upstream commit 05457d96175d25c976ab6241c332ae2eb5e07833 ]

This is needed so that the kernel can handle R_SPARC_UA64 relocations,
which is emitted by LLVM's IAS.

Signed-off-by: Koakuma 
Reviewed-by: Andreas Larsson 
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc: fix error handling in scan_one_device()

2025-10-29T12:59:53+00:00

commit 302c04110f0ce70d25add2496b521132548cd408 upstream.

Once of_device_register() failed, we should call put_device() to
decrement reference count for cleanup. Or it could cause memory leak.
So fix this by calling put_device(), then the name can be freed in
kobject_cleanup().

Calling path: of_device_register() -> of_device_add() -> device_add().
As comment of device_add() says, 'if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count'.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: cf44bbc26cf1 ("[SPARC]: Beginnings of generic of_device framework.")
Signed-off-by: Ma Ke 
Reviewed-by: Andreas Larsson 
Signed-off-by: Andreas Larsson 
Signed-off-by: Greg Kroah-Hartman

sparc64: fix hugetlb for sun4u

2025-10-29T12:59:53+00:00

commit 6fd44a481b3c6111e4801cec964627791d0f3ec5 upstream.

An attempt to exercise sparc hugetlb code in a sun4u-based guest
running under qemu results in the guest hanging due to being stuck
in a trap loop. This is due to invalid hugetlb TTEs being installed
that do not have the expected _PAGE_PMD_HUGE and page size bits set.
Although the breakage has gone apparently unnoticed for several years,
fix it now so there is the option to exercise sparc hugetlb code under
qemu. This can be useful because sun4v support in qemu does not support
linux guests currently and sun4v-based hardware resources may not be
readily available.

Fix tested with a 6.15.2 and 6.16-rc6 kernels by running libhugetlbfs
tests on a qemu guest running Debian 13.

Fixes: c7d9f77d33a7 ("sparc64: Multi-page size support")
Cc: stable@vger.kernel.org
Signed-off-by: Anthony Yznaga 
Tested-by: John Paul Adrian Glaubitz 
Reviewed-by: John Paul Adrian Glaubitz 
Reviewed-by: Andreas Larsson 
Link: https://lore.kernel.org/r/20250716012446.10357-1-anthony.yznaga@oracle.com
Signed-off-by: Andreas Larsson 
Signed-off-by: Greg Kroah-Hartman

sparc: fix accurate exception reporting in copy_{from,to}_user for M7

2025-10-29T12:59:49+00:00

[ Upstream commit 936fb512752af349fc30ccbe0afe14a2ae6d7159 ]

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a couple of bad
calculations. This will fix the return value of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

Fixes: 34060b8fffa7 ("arch/sparc: Add accurate exception reporting in M7memcpy")
Tested-by: John Paul Adrian Glaubitz  # on Oracle SPARC S7
Tested-by: Tony Rodriguez  # S7, see https://lore.kernel.org/r/98564e2e68df2dda0e00c67a75c7f7dfedb33c7e.camel@physik.fu-berlin.de
Signed-off-by: Michael Karcher 
Reviewed-by: Andreas Larsson 
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-5-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc: fix accurate exception reporting in copy_to_user for Niagara 4

2025-10-29T12:59:49+00:00

[ Upstream commit 5a746c1a2c7980de6c888b6373299f751ad7790b ]

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a bad calculation.
This will fix the return value of copy_to_user in a specific faulting case.
The behaviour of memcpy stays unchanged.

Fixes: 957077048009 ("sparc64: Convert NG4copy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz  # on Oracle SPARC T4-1
Signed-off-by: Michael Karcher 
Reviewed-by: Andreas Larsson 
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-4-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc: fix accurate exception reporting in copy_{from_to}_user for Niagara

2025-10-29T12:59:49+00:00

[ Upstream commit 0b67c8fc10b13a9090340c5f8a37d308f4e1571c ]

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a couple of bad
calculations and a broken epilogue in the exception handlers. This will
prevent crashes and ensure correct return values of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

Fixes: 7ae3aaf53f16 ("sparc64: Convert NGcopy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz  # on SPARC T4 with modified kernel to use Niagara 1 code
Tested-by: Magnus Lindholm  # on Sun Fire T2000
Signed-off-by: Michael Karcher 
Tested-by: Ethan Hawke  # on Sun Fire T2000
Tested-by: Ken Link  # on Sun Fire T1000
Reviewed-by: Andreas Larsson 
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-3-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III

2025-10-29T12:59:49+00:00

[ Upstream commit 47b49c06eb62504075f0f2e2227aee2e2c2a58b3 ]

Anthony Yznaga tracked down that a BUG_ON in ext4 code with large folios
enabled resulted from copy_from_user() returning impossibly large values
greater than the size to be copied. This lead to __copy_from_iter()
returning impossible values instead of the actual number of bytes it was
able to copy.

The BUG_ON has been reported in
https://lore.kernel.org/r/b14f55642207e63e907965e209f6323a0df6dcee.camel@physik.fu-berlin.de

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. The exception handlers expect that
%o2 has already been masked during the bulk copy loop, but the masking was
performed after that loop. This will fix the return value of copy_from_user
and copy_to_user in the faulting case. The behaviour of memcpy stays
unchanged.

Fixes: ee841d0aff64 ("sparc64: Convert U3copy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz  # on Sun Netra 240
Reviewed-by: Anthony Yznaga 
Tested-by: René Rebe  # on UltraSparc III+ and UltraSparc IIIi
Signed-off-by: Michael Karcher 
Reviewed-by: Andreas Larsson 
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-2-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC

2025-10-29T12:59:48+00:00

[ Upstream commit 4fba1713001195e59cfc001ff1f2837dab877efb ]

The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. This commit fixes a couple of bad
calculations. This will fix the return value of copy_from_user and
copy_to_user in the faulting case. The behaviour of memcpy stays unchanged.

Fixes: cb736fdbb208 ("sparc64: Convert U1copy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz  # on QEMU 10.0.3
Tested-by: René Rebe  # on Ultra 5 UltraSparc IIi
Tested-by: Jonathan 'theJPster' Pallant  # on Sun Netra T1
Signed-off-by: Michael Karcher 
Reviewed-by: Andreas Larsson 
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-1-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin

sparc/mm: disable preemption in lazy mmu mode

2025-05-02T05:39:16+00:00

commit a1d416bf9faf4f4871cb5a943614a07f80a7d70f upstream.

Since commit 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy
updates") it's been possible for arch_[enter|leave]_lazy_mmu_mode() to be
called without holding a page table lock (for the kernel mappings case),
and therefore it is possible that preemption may occur while in the lazy
mmu mode.  The Sparc lazy mmu implementation is not robust to preemption
since it stores the lazy mode state in a per-cpu structure and does not
attempt to manage that state on task switch.

Powerpc had the same issue and fixed it by explicitly disabling preemption
in arch_enter_lazy_mmu_mode() and re-enabling in
arch_leave_lazy_mmu_mode().  See commit b9ef323ea168 ("powerpc/64s:
Disable preemption in hash lazy mmu mode").

Given Sparc's lazy mmu mode is based on powerpc's, let's fix it in the
same way here.

Link: https://lkml.kernel.org/r/20250303141542.3371656-4-ryan.roberts@arm.com
Fixes: 38e0edb15bd0 ("mm/apply_to_range: call pte function with lazy updates")
Signed-off-by: Ryan Roberts 
Acked-by: David Hildenbrand 
Acked-by: Andreas Larsson 
Acked-by: Juergen Gross 
Cc: Borislav Betkov 
Cc: Boris Ostrovsky 
Cc: Catalin Marinas 
Cc: Dave Hansen 
Cc: David S. Miller 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Juegren Gross 
Cc: Matthew Wilcow (Oracle) 
Cc: Thomas Gleinxer 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

sparc64: Fix incorrect function signature and add prototype for prom_cif_init

2024-08-19T03:33:32+00:00

[ Upstream commit a6c3ea1ec96307dbfbb2f16d96c674c5cc80f445 ]

Remove the unused cif_stack argument and add a protype in oplib_64.h
Commit ef3e035c3a9b ("sparc64: Fix register corruption in top-most
kernel stack frame during boot.") removed the cif_stack argument to
prom_cif init in the declaration at the caller site and the usage of it
within prom_cif_init, but not in the function signature of the function
itself.

This also fixes the following warning:
arch/sparc/prom/p1275.c:52:6: warning: no previous prototype for ‘prom_cif_init’

Fixes: ef3e035c3a9b ("sparc64: Fix register corruption in top-most kernel stack frame during boot.")
Link: https://lore.kernel.org/r/20240710094155.458731-3-andreas@gaisler.com
Signed-off-by: Andreas Larsson 
Signed-off-by: Sasha Levin