Revision tags: v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3, v6.5.2, v6.1.51, v6.5.1, v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45, v6.1.44, v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39, v6.1.38, v6.1.37, v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29 |
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#
3b939ba0 |
| 16-May-2023 |
Arnd Bergmann <arnd@arndb.de> |
x86/usercopy: Include arch_wb_cache_pmem() declaration
arch_wb_cache_pmem() is declared in a global header but defined by the architecture. On x86, the implementation needs to include the header to
x86/usercopy: Include arch_wb_cache_pmem() declaration
arch_wb_cache_pmem() is declared in a global header but defined by the architecture. On x86, the implementation needs to include the header to avoid this warning:
arch/x86/lib/usercopy_64.c:39:6: error: no previous prototype for 'arch_wb_cache_pmem' [-Werror=missing-prototypes]
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://lore.kernel.org/all/20230516193549.544673-18-arnd%40kernel.org
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Revision tags: v6.1.28, v6.1.27, v6.1.26, v6.3, v6.1.25 |
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e1f2750e |
| 19-Apr-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
x86: remove 'zerorest' argument from __copy_user_nocache()
Every caller passes in zero, meaning they don't want any partial copy to zero the remainder of the destination buffer.
Which is just as we
x86: remove 'zerorest' argument from __copy_user_nocache()
Every caller passes in zero, meaning they don't want any partial copy to zero the remainder of the destination buffer.
Which is just as well, because the implementation of that function didn't actually even look at that argument, and wasn't even aware it existed, although some misleading comments did mention it still.
The 'zerorest' thing is a historical artifact of how "copy_from_user()" worked, in that it would zero the rest of the kernel buffer that it copied into.
That zeroing still exists, but it's long since been moved to generic code, and the raw architecture-specific code doesn't do it. See _copy_from_user() in lib/usercopy.c for this all.
However, while __copy_user_nocache() shares some history and superficial other similarities with copy_from_user(), it is in many ways also very different.
In particular, while the code makes it *look* similar to the generic user copy functions that can copy both to and from user space, and take faults on both reads and writes as a result, __copy_user_nocache() does no such thing at all.
__copy_user_nocache() always copies to kernel space, and will never take a page fault on the destination. What *can* happen, though, is that the non-temporal stores take a machine check because one of the use cases is for writing to stable memory, and any memory errors would then take synchronous faults.
So __copy_user_nocache() does look a lot like copy_from_user(), but has faulting behavior that is more akin to our old copy_in_user() (which no longer exists, but copied from user space to user space and could fault on both source and destination).
And it very much does not have the "zero the end of the destination buffer", since a problem with the destination buffer is very possibly the very source of the partial copy.
So this whole thing was just a confusing historical artifact from having shared some code with a completely different function with completely different use cases.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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3639a535 |
| 15-Apr-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
x86: move stac/clac from user copy routines into callers
This is preparatory work for inlining the 'rep movs' case, but also a cleanup. The __copy_user_nocache() function was mis-used by the rdma c
x86: move stac/clac from user copy routines into callers
This is preparatory work for inlining the 'rep movs' case, but also a cleanup. The __copy_user_nocache() function was mis-used by the rdma code to do uncached kernel copies that don't actually want user copies at all, and as a result doesn't want the stac/clac either.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: v6.1.24, v6.1.23, v6.1.22, v6.1.21, v6.1.20 |
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b9da86e3 |
| 15-Mar-2023 |
Ira Weiny <ira.weiny@intel.com> |
x86/uaccess: Remove memcpy_page_flushcache()
Commit 21b56c847753 ("iov_iter: get rid of separate bvec and xarray callbacks") removed the calls to memcpy_page_flushcache().
In addition, memcpy_page_
x86/uaccess: Remove memcpy_page_flushcache()
Commit 21b56c847753 ("iov_iter: get rid of separate bvec and xarray callbacks") removed the calls to memcpy_page_flushcache().
In addition, memcpy_page_flushcache() uses the deprecated kmap_atomic().
Remove the unused x86 memcpy_page_flushcache() implementation and also get rid of one more kmap_atomic() user.
[ dhansen: tweak changelog ]
Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/20221230-kmap-x86-v1-1-15f1ecccab50%40intel.com
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Revision tags: v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14, v6.0.13, v6.1, v6.0.12, v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42 |
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#
0db7058e |
| 24-May-2022 |
Borislav Petkov <bp@suse.de> |
x86/clear_user: Make it faster
Based on a patch by Mark Hemment <markhemm@googlemail.com> and incorporating very sane suggestions from Linus.
The point here is to have the default case with FSRM -
x86/clear_user: Make it faster
Based on a patch by Mark Hemment <markhemm@googlemail.com> and incorporating very sane suggestions from Linus.
The point here is to have the default case with FSRM - which is supposed to be the majority of x86 hw out there - if not now then soon - be directly inlined into the instruction stream so that no function call overhead is taking place.
Drop the early clobbers from the @size and @addr operands as those are not needed anymore since we have single instruction alternatives.
The benchmarks I ran would show very small improvements and a PF benchmark would even show weird things like slowdowns with higher core counts.
So for a ~6m running the git test suite, the function gets called under 700K times, all from padzero():
<...>-2536 [006] ..... 261.208801: padzero: to: 0x55b0663ed214, size: 3564, cycles: 21900 <...>-2536 [006] ..... 261.208819: padzero: to: 0x7f061adca078, size: 3976, cycles: 17160 <...>-2537 [008] ..... 261.211027: padzero: to: 0x5572d019e240, size: 3520, cycles: 23850 <...>-2537 [008] ..... 261.211049: padzero: to: 0x7f1288dc9078, size: 3976, cycles: 15900 ...
which is around 1%-ish of the total time and which is consistent with the benchmark numbers.
So Mel gave me the idea to simply measure how fast the function becomes. I.e.:
start = rdtsc_ordered(); ret = __clear_user(to, n); end = rdtsc_ordered();
Computing the mean average of all the samples collected during the test suite run then shows some improvement:
clear_user_original: Amean: 9219.71 (Sum: 6340154910, samples: 687674)
fsrm: Amean: 8030.63 (Sum: 5522277720, samples: 687652)
That's on Zen3.
The situation looks a lot more confusing on Intel:
Icelake:
clear_user_original: Amean: 19679.4 (Sum: 13652560764, samples: 693750) Amean: 19743.7 (Sum: 13693470604, samples: 693562)
(I ran it twice just to be sure.)
ERMS: Amean: 20374.3 (Sum: 13910601024, samples: 682752) Amean: 20453.7 (Sum: 14186223606, samples: 693576)
FSRM: Amean: 20458.2 (Sum: 13918381386, sample s: 680331)
The original microbenchmark which people were complaining about:
for i in $(seq 1 10); do dd if=/dev/zero of=/dev/null bs=1M status=progress count=65536; done 2>&1 | grep copied 32207011840 bytes (32 GB, 30 GiB) copied, 1 s, 32.2 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.93069 s, 35.6 GB/s 37597741056 bytes (38 GB, 35 GiB) copied, 1 s, 37.6 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.78017 s, 38.6 GB/s 62020124672 bytes (62 GB, 58 GiB) copied, 2 s, 31.0 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 2.13716 s, 32.2 GB/s 60010004480 bytes (60 GB, 56 GiB) copied, 1 s, 60.0 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.14129 s, 60.2 GB/s 53212086272 bytes (53 GB, 50 GiB) copied, 1 s, 53.2 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.28398 s, 53.5 GB/s 55698259968 bytes (56 GB, 52 GiB) copied, 1 s, 55.7 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.22507 s, 56.1 GB/s 55306092544 bytes (55 GB, 52 GiB) copied, 1 s, 55.3 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.23647 s, 55.6 GB/s 54387539968 bytes (54 GB, 51 GiB) copied, 1 s, 54.4 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.25693 s, 54.7 GB/s 50566529024 bytes (51 GB, 47 GiB) copied, 1 s, 50.6 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.35096 s, 50.9 GB/s 58308165632 bytes (58 GB, 54 GiB) copied, 1 s, 58.3 GB/s 68719476736 bytes (69 GB, 64 GiB) copied, 1.17394 s, 58.5 GB/s
Now the same thing with smaller buffers:
for i in $(seq 1 10); do dd if=/dev/zero of=/dev/null bs=1M status=progress count=8192; done 2>&1 | grep copied 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.28485 s, 30.2 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.276112 s, 31.1 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.29136 s, 29.5 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.283803 s, 30.3 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.306503 s, 28.0 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.349169 s, 24.6 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.276912 s, 31.0 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.265356 s, 32.4 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.28464 s, 30.2 GB/s 8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.242998 s, 35.3 GB/s
is also not conclusive because it all depends on the buffer sizes, their alignments and when the microcode detects that cachelines can be aggregated properly and copied in bigger sizes.
Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/CAHk-=wh=Mu_EYhtOmPn6AxoQZyEh-4fo2Zx3G7rBv1g7vwoKiw@mail.gmail.com
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Revision tags: v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35 |
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a6823e4e |
| 19-Apr-2022 |
Mikulas Patocka <mpatocka@redhat.com> |
x86: __memcpy_flushcache: fix wrong alignment if size > 2^32
The first "if" condition in __memcpy_flushcache is supposed to align the "dest" variable to 8 bytes and copy data up to this alignment.
x86: __memcpy_flushcache: fix wrong alignment if size > 2^32
The first "if" condition in __memcpy_flushcache is supposed to align the "dest" variable to 8 bytes and copy data up to this alignment. However, this condition may misbehave if "size" is greater than 4GiB.
The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both arguments to unsigned int and selects the smaller one. However, the cast truncates high bits in "size" and it results in misbehavior.
For example:
suppose that size == 0x100000001, dest == 0x200000002 min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1; ... dest += 0x1;
so we copy just one byte "and" dest remains unaligned.
This patch fixes the bug by replacing unsigned with size_t.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15, v5.16, v5.15.10, v5.15.9, v5.15.8, v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3, v5.15.2 |
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d5d797dc |
| 10-Nov-2021 |
Peter Zijlstra <peterz@infradead.org> |
x86/usercopy: Remove .fixup usage
Typically usercopy does whole word copies followed by a number of byte copies to finish the tail. This means that on exception it needs to compute the remaining len
x86/usercopy: Remove .fixup usage
Typically usercopy does whole word copies followed by a number of byte copies to finish the tail. This means that on exception it needs to compute the remaining length as: words*sizeof(long) + bytes.
Create a new extable handler to do just this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20211110101326.081701085@infradead.org
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#
4640802e |
| 19-Apr-2022 |
Mikulas Patocka <mpatocka@redhat.com> |
x86: __memcpy_flushcache: fix wrong alignment if size > 2^32
[ Upstream commit a6823e4e360fe975bd3da4ab156df7c74c8b07f3 ]
The first "if" condition in __memcpy_flushcache is supposed to align the "d
x86: __memcpy_flushcache: fix wrong alignment if size > 2^32
[ Upstream commit a6823e4e360fe975bd3da4ab156df7c74c8b07f3 ]
The first "if" condition in __memcpy_flushcache is supposed to align the "dest" variable to 8 bytes and copy data up to this alignment. However, this condition may misbehave if "size" is greater than 4GiB.
The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both arguments to unsigned int and selects the smaller one. However, the cast truncates high bits in "size" and it results in misbehavior.
For example:
suppose that size == 0x100000001, dest == 0x200000002 min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1; ... dest += 0x1;
so we copy just one byte "and" dest remains unaligned.
This patch fixes the bug by replacing unsigned with size_t.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Revision tags: v5.15.1, v5.15, v5.14.14, v5.14.13, v5.14.12, v5.14.11, v5.14.10, v5.14.9, v5.14.8, v5.14.7, v5.14.6, v5.10.67, v5.10.66, v5.14.5, v5.14.4, v5.10.65, v5.14.3, v5.10.64, v5.14.2, v5.10.63, v5.14.1, v5.10.62, v5.14, v5.10.61, v5.10.60, v5.10.53, v5.10.52, v5.10.51, v5.10.50, v5.10.49, v5.13, v5.10.46, v5.10.43, v5.10.42, v5.10.41, v5.10.40, v5.10.39, v5.4.119, v5.10.36, v5.10.35, v5.10.34, v5.4.116, v5.10.33, v5.12, v5.10.32, v5.10.31, v5.10.30, v5.10.27, v5.10.26, v5.10.25, v5.10.24, v5.10.23, v5.10.22, v5.10.21, v5.10.20, v5.10.19, v5.4.101, v5.10.18, v5.10.17, v5.11, v5.10.16, v5.10.15, v5.10.14, v5.10, v5.8.17, v5.8.16, v5.8.15, v5.9, v5.8.14 |
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#
ec6347bb |
| 05-Oct-2020 |
Dan Williams <dan.j.williams@intel.com> |
x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast() implementation Linus points out that memcpy_mcsafe() is poorly named
x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast() implementation Linus points out that memcpy_mcsafe() is poorly named relative to communicating the scope of the interface. Specifically what addresses are valid to pass as source, destination, and what faults / exceptions are handled.
Of particular concern is that even though x86 might be able to handle the semantics of copy_mc_to_user() with its common copy_user_generic() implementation other archs likely need / want an explicit path for this case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote: > > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote: > > > > However now I see that copy_user_generic() works for the wrong reason. > > It works because the exception on the source address due to poison > > looks no different than a write fault on the user address to the > > caller, it's still just a short copy. So it makes copy_to_user() work > > for the wrong reason relative to the name. > > Right. > > And it won't work that way on other architectures. On x86, we have a > generic function that can take faults on either side, and we use it > for both cases (and for the "in_user" case too), but that's an > artifact of the architecture oddity. > > In fact, it's probably wrong even on x86 - because it can hide bugs - > but writing those things is painful enough that everybody prefers > having just one function.
Replace a single top-level memcpy_mcsafe() with either copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the low-level x86 implementation formerly named memcpy_mcsafe(). It is used as the slow / careful backend that is supplanted by a fast copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S to its own file means that perf no longer needs to track dependencies for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: <stable@vger.kernel.org> Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
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Revision tags: v5.8.13, v5.8.12 |
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#
a1cd6c2a |
| 25-Sep-2020 |
Mikulas Patocka <mpatocka@redhat.com> |
arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
If we copy less than 8 bytes and if the destination crosses a cache line, __copy_user_flushcache would invalidate only the fi
arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback
If we copy less than 8 bytes and if the destination crosses a cache line, __copy_user_flushcache would invalidate only the first cache line.
This patch makes it invalidate the second cache line as well.
Fixes: 0aed55af88345b ("x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dan Williams <dan.j.wiilliams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: v5.8.11, v5.8.10, v5.8.9, v5.8.8, v5.8.7, v5.8.6, v5.4.62, v5.8.5, v5.8.4, v5.4.61, v5.8.3, v5.4.60, v5.8.2, v5.4.59, v5.8.1, v5.4.58, v5.4.57, v5.4.56, v5.8, v5.7.12, v5.4.55, v5.7.11, v5.4.54, v5.7.10, v5.4.53, v5.4.52, v5.7.9, v5.7.8, v5.4.51, v5.4.50, v5.7.7, v5.4.49, v5.7.6, v5.7.5, v5.4.48, v5.7.4 |
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#
bb5570ad |
| 18-Jun-2020 |
Matt Fleming <matt@codeblueprint.co.uk> |
x86/asm/64: Align start of __clear_user() loop to 16-bytes
x86 CPUs can suffer severe performance drops if a tight loop, such as the ones in __clear_user(), straddles a 16-byte instruction fetch win
x86/asm/64: Align start of __clear_user() loop to 16-bytes
x86 CPUs can suffer severe performance drops if a tight loop, such as the ones in __clear_user(), straddles a 16-byte instruction fetch window, or worse, a 64-byte cacheline. This issues was discovered in the SUSE kernel with the following commit,
1153933703d9 ("x86/asm/64: Micro-optimize __clear_user() - Use immediate constants")
which increased the code object size from 10 bytes to 15 bytes and caused the 8-byte copy loop in __clear_user() to be split across a 64-byte cacheline.
Aligning the start of the loop to 16-bytes makes this fit neatly inside a single instruction fetch window again and restores the performance of __clear_user() which is used heavily when reading from /dev/zero.
Here are some numbers from running libmicro's read_z* and pread_z* microbenchmarks which read from /dev/zero:
Zen 1 (Naples)
libmicro-file 5.7.0-rc6 5.7.0-rc6 5.7.0-rc6 revert-1153933703d9+ align16+ Time mean95-pread_z100k 9.9195 ( 0.00%) 5.9856 ( 39.66%) 5.9938 ( 39.58%) Time mean95-pread_z10k 1.1378 ( 0.00%) 0.7450 ( 34.52%) 0.7467 ( 34.38%) Time mean95-pread_z1k 0.2623 ( 0.00%) 0.2251 ( 14.18%) 0.2252 ( 14.15%) Time mean95-pread_zw100k 9.9974 ( 0.00%) 6.0648 ( 39.34%) 6.0756 ( 39.23%) Time mean95-read_z100k 9.8940 ( 0.00%) 5.9885 ( 39.47%) 5.9994 ( 39.36%) Time mean95-read_z10k 1.1394 ( 0.00%) 0.7483 ( 34.33%) 0.7482 ( 34.33%)
Note that this doesn't affect Haswell or Broadwell microarchitectures which seem to avoid the alignment issue by executing the loop straight out of the Loop Stream Detector (verified using perf events).
Fixes: 1153933703d9 ("x86/asm/64: Micro-optimize __clear_user() - Use immediate constants") Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # v4.19+ Link: https://lkml.kernel.org/r/20200618102002.30034-1-matt@codeblueprint.co.uk
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Revision tags: v5.7.3, v5.4.47, v5.4.46, v5.7.2, v5.4.45, v5.7.1, v5.4.44, v5.7, v5.4.43, v5.4.42, v5.4.41, v5.4.40, v5.4.39, v5.4.38, v5.4.37, v5.4.36, v5.4.35, v5.4.34, v5.4.33, v5.4.32, v5.4.31, v5.4.30, v5.4.29, v5.6, v5.4.28, v5.4.27, v5.4.26, v5.4.25, v5.4.24, v5.4.23, v5.4.22, v5.4.21, v5.4.20, v5.4.19, v5.4.18, v5.4.17, v5.4.16, v5.5, v5.4.15, v5.4.14, v5.4.13, v5.4.12, v5.4.11, v5.4.10, v5.4.9, v5.4.8, v5.4.7, v5.4.6, v5.4.5, v5.4.4, v5.4.3, v5.3.15, v5.4.2, v5.4.1, v5.3.14, v5.4, v5.3.13, v5.3.12, v5.3.11, v5.3.10, v5.3.9, v5.3.8, v5.3.7, v5.3.6, v5.3.5, v5.3.4, v5.3.3, v5.3.2, v5.3.1, v5.3, v5.2.14, v5.3-rc8, v5.2.13, v5.2.12, v5.2.11, v5.2.10, v5.2.9, v5.2.8, v5.2.7, v5.2.6, v5.2.5, v5.2.4, v5.2.3, v5.2.2 |
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#
5e307a6b |
| 17-Jul-2019 |
Josh Poimboeuf <jpoimboe@redhat.com> |
x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail()
After adding mcsafe_handle_tail() to the objtool uaccess safe list, objtool reports:
arch/x86/lib/usercopy_64.o: warning: obj
x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail()
After adding mcsafe_handle_tail() to the objtool uaccess safe list, objtool reports:
arch/x86/lib/usercopy_64.o: warning: objtool: mcsafe_handle_tail()+0x0: call to __fentry__() with UACCESS enabled
With SMAP, this function is called with AC=1, so it needs to be careful about which functions it calls. Disable the ftrace entry hook, which can potentially pull in a lot of extra code.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/8e13d6f0da1c8a3f7603903da6cbf6d582bbfe10.1563413318.git.jpoimboe@redhat.com
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Revision tags: v5.2.1, v5.2, v5.1.16, v5.1.15, v5.1.14, v5.1.13, v5.1.12, v5.1.11, v5.1.10, v5.1.9, v5.1.8, v5.1.7, v5.1.6, v5.1.5, v5.1.4 |
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#
457c8996 |
| 19-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was use
treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Revision tags: v5.1.3, v5.1.2, v5.1.1, v5.0.14, v5.1, v5.0.13, v5.0.12, v5.0.11, v5.0.10, v5.0.9, v5.0.8, v5.0.7, v5.0.6, v5.0.5, v5.0.4, v5.0.3, v4.19.29, v5.0.2, v4.19.28, v5.0.1, v4.19.27, v5.0 |
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#
3693ca81 |
| 01-Mar-2019 |
Peter Zijlstra <peterz@infradead.org> |
x86/uaccess: Move copy_user_handle_tail() into asm
By writing the function in asm we avoid cross object code flow and objtool no longer gets confused about a 'stray' CLAC.
Also; the asm version is
x86/uaccess: Move copy_user_handle_tail() into asm
By writing the function in asm we avoid cross object code flow and objtool no longer gets confused about a 'stray' CLAC.
Also; the asm version is actually _simpler_.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Revision tags: v4.19.26, v4.19.25, v4.19.24, v4.19.23, v4.19.22, v4.19.21, v4.19.20, v4.19.19, v4.19.18, v4.19.17, v4.19.16, v4.19.15, v4.19.14 |
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#
96d4f267 |
| 03-Jan-2019 |
Linus Torvalds <torvalds@linux-foundation.org> |
Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old
Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Revision tags: v4.19.13, v4.19.12, v4.19.11, v4.19.10, v4.19.9, v4.19.8, v4.19.7, v4.19.6, v4.19.5, v4.19.4, v4.18.20, v4.19.3, v4.18.19, v4.19.2, v4.18.18, v4.18.17, v4.19.1, v4.19, v4.18.16, v4.18.15, v4.18.14, v4.18.13, v4.18.12, v4.18.11, v4.18.10, v4.18.9, v4.18.7, v4.18.6, v4.18.5, v4.17.18, v4.18.4, v4.18.3, v4.17.17, v4.18.2, v4.17.16, v4.17.15, v4.18.1, v4.18, v4.17.14 |
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#
02101c45 |
| 08-Aug-2018 |
Mikulas Patocka <mpatocka@redhat.com> |
x86/asm: Optimize memcpy_flushcache()
I use memcpy_flushcache() in my persistent memory driver for metadata updates, there are many 8-byte and 16-byte updates and it turns out that the overhead of m
x86/asm: Optimize memcpy_flushcache()
I use memcpy_flushcache() in my persistent memory driver for metadata updates, there are many 8-byte and 16-byte updates and it turns out that the overhead of memcpy_flushcache causes 2% performance degradation compared to "movnti" instruction explicitly coded using inline assembler.
The tests were done on a Skylake processor with persistent memory emulated using the "memmap" kernel parameter. dd was used to copy data to the dm-writecache target.
This patch recognizes memcpy_flushcache calls with constant short length and turns them into inline assembler - so that I don't have to use inline assembler in the driver.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: device-mapper development <dm-devel@redhat.com> Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1808081720460.24747@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
75045f77 |
| 28-Aug-2018 |
Jann Horn <jannh@google.com> |
x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups
Currently, most fixups for attempting to access userspace memory are handled using _ASM_EXTABLE, which is also used for various other types
x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups
Currently, most fixups for attempting to access userspace memory are handled using _ASM_EXTABLE, which is also used for various other types of fixups (e.g. safe MSR access, IRET failures, and a bunch of other things). In order to make it possible to add special safety checks to uaccess fixups (in particular, checking whether the fault address is actually in userspace), introduce a new exception table handler ex_handler_uaccess() and wire it up to all the user access fixups (excluding ones that already use _ASM_EXTABLE_EX).
Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: kernel-hardening@lists.openwall.com Cc: dvyukov@google.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20180828201421.157735-5-jannh@google.com
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Revision tags: v4.17.13, v4.17.12, v4.17.11, v4.17.10, v4.17.9, v4.17.8, v4.17.7, v4.17.6, v4.17.5, v4.17.4, v4.17.3, v4.17.2, v4.17.1, v4.17 |
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#
12c89130 |
| 03-May-2018 |
Dan Williams <dan.j.williams@intel.com> |
x86/asm/memcpy_mcsafe: Add write-protection-fault handling
In preparation for using memcpy_mcsafe() to handle user copies it needs to be to handle write-protection faults while writing user pages. A
x86/asm/memcpy_mcsafe: Add write-protection-fault handling
In preparation for using memcpy_mcsafe() to handle user copies it needs to be to handle write-protection faults while writing user pages. Add MMU-fault handlers alongside the machine-check exception handlers.
Note that the machine check fault exception handling makes assumptions about source buffer alignment and poison alignment. In the write fault case, given the destination buffer is arbitrarily aligned, it needs a separate / additional fault handling approach. The mcsafe_handle_tail() helper is reused. The @limit argument is set to @len since there is no safety concern about retriggering an MMU fault, and this simplifies the assembly.
Co-developed-by: Tony Luck <tony.luck@intel.com> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539238635.31796.14056325365122961778.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
11539337 |
| 07-May-2018 |
Alexey Dobriyan <adobriyan@gmail.com> |
x86/asm/64: Micro-optimize __clear_user() - Use immediate constants
Save two registers. Adding constants should be just as fast as adding registers.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.
x86/asm/64: Micro-optimize __clear_user() - Use immediate constants
Save two registers. Adding constants should be just as fast as adding registers.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180507213937.GB32406@avx2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Revision tags: v4.16, v4.15, v4.13.16, v4.14, v4.13.5, v4.13, v4.12 |
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#
4e4f00a9 |
| 30-May-2017 |
Dan Williams <dan.j.williams@intel.com> |
x86, dax, libnvdimm: remove wb_cache_pmem() indirection
With all handling of the CONFIG_ARCH_HAS_PMEM_API case being moved to libnvdimm and the pmem driver directly we do not need to provide global
x86, dax, libnvdimm: remove wb_cache_pmem() indirection
With all handling of the CONFIG_ARCH_HAS_PMEM_API case being moved to libnvdimm and the pmem driver directly we do not need to provide global wrappers and fallbacks in the CONFIG_ARCH_HAS_PMEM_API=n case. The pmem driver will simply not link to arch_wb_cache_pmem() in that case. Same as before, pmem flushing is only defined for x86_64, via clean_cache_range(), but it is straightforward to add other archs in the future.
arch_wb_cache_pmem() is an exported function since the pmem module needs to find it, but it is privately declared in drivers/nvdimm/pmem.h because there are no consumers outside of the pmem driver.
Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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#
0aed55af |
| 29-May-2017 |
Dan Williams <dan.j.williams@intel.com> |
x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations
The pmem driver has a need to transfer data with a persistent memory destination and be able to rely on the fact
x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations
The pmem driver has a need to transfer data with a persistent memory destination and be able to rely on the fact that the destination writes are not cached. It is sufficient for the writes to be flushed to a cpu-store-buffer (non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync() to ensure data-writes have reached a power-fail-safe zone in the platform. The fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn around and fence previous writes with an "sfence".
Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and memcpy_flushcache, that guarantee that the destination buffer is not dirty in the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines will be used to replace the "pmem api" (include/linux/pmem.h + arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache() and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE config symbol, and fallback to copy_from_iter_nocache() and plain memcpy() otherwise.
This is meant to satisfy the concern from Linus that if a driver wants to do something beyond the normal nocache semantics it should be something private to that driver [1], and Al's concern that anything uaccess related belongs with the rest of the uaccess code [2].
The first consumer of this interface is a new 'copy_from_iter' dax operation so that pmem can inject cache maintenance operations without imposing this overhead on other dax-capable drivers.
[1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html
Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Revision tags: v4.10.17, v4.10.16, v4.10.15, v4.10.14, v4.10.13, v4.10.12, v4.10.11, v4.10.10, v4.10.9, v4.10.8, v4.10.7, v4.10.6 |
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#
a41e0d75 |
| 25-Mar-2017 |
Al Viro <viro@zeniv.linux.org.uk> |
x86: don't wank with magical size in __copy_in_user()
... especially since copy_in_user() doesn't
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
122b05dd |
| 25-Mar-2017 |
Al Viro <viro@zeniv.linux.org.uk> |
amd64: get rid of zeroing
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Revision tags: v4.10.5, v4.10.4, v4.10.3, v4.10.2, v4.10.1, v4.10, v4.9, openbmc-4.4-20161121-1, v4.4.33, v4.4.32, v4.4.31, v4.4.30, v4.4.29, v4.4.28, v4.4.27, v4.7.10, openbmc-4.4-20161021-1, v4.7.9, v4.4.26, v4.7.8, v4.4.25, v4.4.24, v4.7.7, v4.8, v4.4.23, v4.7.6, v4.7.5, v4.4.22, v4.4.21, v4.7.4, v4.7.3, v4.4.20, v4.7.2, v4.4.19, openbmc-4.4-20160819-1, v4.7.1, v4.4.18, v4.4.17, openbmc-4.4-20160804-1, v4.4.16, v4.7, openbmc-4.4-20160722-1, openbmc-20160722-1 |
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#
13d4ea09 |
| 14-Jul-2016 |
Andy Lutomirski <luto@kernel.org> |
x86/uaccess: Move thread_info::addr_limit to thread_struct
struct thread_info is a legacy mess. To prepare for its partial removal, move thread_info::addr_limit out.
As an added benefit, this way
x86/uaccess: Move thread_info::addr_limit to thread_struct
struct thread_info is a legacy mess. To prepare for its partial removal, move thread_info::addr_limit out.
As an added benefit, this way is simpler.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/15bee834d09402b47ac86f2feccdf6529f9bc5b0.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
e683014c |
| 13-Jul-2016 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
x86/lib: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to m
x86/lib: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using.
Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. Build testing revealed a couple implicit header usage issues that were fixed.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160714001901.31603-5-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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