Peter Zijlstra
e9afa7c1ef
commitd86564a2f0upstream. Jann reported that x86 was missing required TLB invalidates when he hit the !*batch slow path in tlb_remove_table(). This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache) invalidates, the PowerPC-hash where this code originated and the Sparc-hash where this was subsequently used did not need that. ARM which later used this put an explicit TLB invalidate in their __p*_free_tlb() functions, and PowerPC-radix followed that example. But when we hooked up x86 we failed to consider this. Fix this by (optionally) hooking tlb_remove_table() into the TLB invalidate code. NOTE: s390 was also needing something like this and might now be able to use the generic code again. [ Modified to be on top of Nick's cleanups, which simplified this patch now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ] Fixes:9e52fc2b50("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: Will Deacon <will.deacon@arm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.