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Michael Karcher 91eda032eb sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III
[ 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: ee841d0aff ("sparc64: Convert U3copy_{from,to}_user to accurate exception reporting.")
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # on Sun Netra 240
Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Tested-by: René Rebe <rene@exactcode.com> # on UltraSparc III+ and UltraSparc IIIi
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20250905-memcpy_series-v4-2-1ca72dda195b@mkarcher.dialup.fu-berlin.de
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15 11:56:35 +02:00
arch sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III 2025-10-15 11:56:35 +02:00
block block: use int to store blk_stack_limits() return value 2025-10-15 11:56:27 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2025-04-25 10:44:04 +02:00
crypto crypto: rng - Ensure set_ent is always present 2025-10-15 11:56:24 +02:00
Documentation Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram 2025-10-15 11:56:35 +02:00
drivers wifi: ath10k: avoid unnecessary wait for service ready message 2025-10-15 11:56:35 +02:00
fs f2fs: fix zero-sized extent for precache extents 2025-10-15 11:56:34 +02:00
include bpf: Enforce expected_attach_type for tailcall compatibility 2025-10-15 11:56:29 +02:00
init init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRD 2025-10-15 11:56:25 +02:00
io_uring io_uring: include dying ring in task_work "should cancel" state 2025-09-25 10:58:53 +02:00
ipc ipc: fix to protect IPCS lookups using RCU 2025-06-27 11:07:30 +01:00
kernel bpf: Enforce expected_attach_type for tailcall compatibility 2025-10-15 11:56:29 +02:00
lib minmax: don't use max() in situations that want a C constant expression 2025-10-15 11:56:21 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm minmax: make generic MIN() and MAX() macros available everywhere 2025-10-02 13:40:43 +02:00
net wifi: mac80211: fix Rx packet handling when pubsta information is not available 2025-10-15 11:56:35 +02:00
rust rust: module: place cleanup_module() in .exit.text section 2025-07-06 10:57:54 +02:00
samples ftrace/samples: Fix function size computation 2025-09-19 16:29:56 +02:00
scripts gcc-plugins: Remove TODO_verify_il for GCC >= 16 2025-10-15 11:56:20 +02:00
security apparmor: use the condition in AA_BUG_FMT even with debug disabled 2025-08-28 16:26:01 +02:00
sound ASoC: Intel: bytcr_rt5651: Fix invalid quirk input mapping 2025-10-15 11:56:33 +02:00
tools tools/nolibc: make time_t robust if __kernel_old_time_t is missing in host headers 2025-10-15 11:56:29 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-06-27 11:07:25 +01:00
virt KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() 2024-06-27 13:46:21 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Remove *.orig pattern from .gitignore 2024-10-17 15:21:15 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS sign-file,extract-cert: move common SSL helper functions to a header 2025-04-25 10:44:04 +02:00
Makefile Linux 6.1.155 2025-10-02 13:40:43 +02:00
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