| Message ID | 20200916225519.w7Xau%akpm@linux-foundation.org |
|---|---|
| State | New |
| Headers | show |
| Series | + arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch added to -mm tree | expand |
--- a/arch/x86/lib/usercopy_64.c~arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback +++ a/arch/x86/lib/usercopy_64.c @@ -120,7 +120,7 @@ long __copy_user_flushcache(void *dst, c */ if (size < 8) { if (!IS_ALIGNED(dest, 4) || size != 4) - clean_cache_range(dst, 1); + clean_cache_range(dst, size); } else { if (!IS_ALIGNED(dest, 8)) { dest = ALIGN(dest, boot_cpu_data.x86_clflush_size);
The patch titled Subject: arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writeback has been added to the -mm tree. Its filename is arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/arch-x86-lib-usercopy_64c-fix-__copy_user_flushcache-cache-writeback.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mikulas Patocka <mpatocka@redhat.com> Subject: 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. Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@file01.intranet.prod.int.rdu2.redhat.com Fixes: 0aed55af88345b ("x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations") Signed-off-by: Mikulas Patocka <mpatocka@redhat.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: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- arch/x86/lib/usercopy_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)