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| author | Linus Torvalds <[email protected]> | 2024-10-30 02:03:31 +0000 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2024-10-30 21:38:10 +0000 |
| commit | 0fc810ae3ae110f9e2fcccce80fc8c8d62f97907 (patch) | |
| tree | 983d3b661ca5c20363d7066b01252b6473ee95a3 /drivers/acpi/cppc_acpi.c | |
| parent | Merge tag 'perf-tools-fixes-for-v6.12-2-2024-10-30' of git://git.kernel.org/p... (diff) | |
| download | kernel-0fc810ae3ae110f9e2fcccce80fc8c8d62f97907.tar.gz kernel-0fc810ae3ae110f9e2fcccce80fc8c8d62f97907.zip | |
x86/uaccess: Avoid barrier_nospec() in 64-bit copy_from_user()
The barrier_nospec() in 64-bit copy_from_user() is slow. Instead use
pointer masking to force the user pointer to all 1's for an invalid
address.
The kernel test robot reports a 2.6% improvement in the per_thread_ops
benchmark [1].
This is a variation on a patch originally by Josh Poimboeuf [2].
Link: https://lore.kernel.org/[email protected] [1]
Link: https://lore.kernel.org/5b887fe4c580214900e21f6c61095adf9a142735.1730166635.git.jpoimboe@kernel.org [2]
Tested-and-reviewed-by: Josh Poimboeuf <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'drivers/acpi/cppc_acpi.c')
0 files changed, 0 insertions, 0 deletions