From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: sort out the flush_icache_range mess Date: Sun, 10 May 2020 09:54:39 +0200 Message-ID: <20200510075510.987823-1-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane-mx.org@lists.infradead.org To: Andrew Morton , Arnd Bergmann , Roman Zippel Cc: linux-arch@vger.kernel.org, linux-xtensa@linux-xtensa.org, Michal Simek , Jessica Yu , linux-ia64@vger.kernel.org, linux-c6x-dev@linux-c6x.org, linux-sh@vger.kernel.org, linux-hexagon@vger.kernel.org, x86@kernel.org, linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-m68k@lists.linux-m68k.org, openrisc@lists.librecores.org, linux-alpha@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: linux-arch.vger.kernel.org Hi all, flush_icache_range is mostly used for kernel address, except for the following cases: - the nommu brk and mmap implementations, - the read_code helper that is only used for binfmt_flat, binfmt_elf_fdpic, and binfmt_aout including the broken ia32 compat version - binfmt_flat itself, none of which really are used by a typical MMU enabled kernel, as a.out can only be build for alpha and m68k to start with. But strangely enough commit ae92ef8a4424 ("PATCH] flush icache in correct context") added a "set_fs(KERNEL_DS)" around the flush_icache_range call in the module loader, because apparently m68k assumed user pointers. This series first cleans up the cacheflush implementations, largely by switching as much as possible to the asm-generic version after a few preparations, then moves the misnamed current flush_icache_user_range to a new name, to finally introduce a real flush_icache_user_range to be used for the above use cases to flush the instruction cache for a userspace address range. The last patch then drops the set_fs in the module code and moves it into the m68k implementation. A git tree is available here: git://git.infradead.org/users/hch/misc.git flush_icache_range Gitweb: http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/flush_icache_range From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Christoph Hellwig Subject: sort out the flush_icache_range mess Date: Sun, 10 May 2020 09:54:39 +0200 Message-ID: <20200510075510.987823-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Andrew Morton , Arnd Bergmann , Roman Zippel Cc: Jessica Yu , Michal Simek , x86@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, linux-fsdevel@vger.kernel.org List-ID: Message-ID: <20200510075439.BjFf21k8r5z2F2HtFJfgfcsOv0-RU4mZ1uQ_yDvt-Uw@z> Hi all, flush_icache_range is mostly used for kernel address, except for the foll= owing cases: - the nommu brk and mmap implementations, - the read_code helper that is only used for binfmt_flat, binfmt_elf_fdp= ic, and binfmt_aout including the broken ia32 compat version - binfmt_flat itself, none of which really are used by a typical MMU enabled kernel, as a.out c= an only be build for alpha and m68k to start with. But strangely enough commit ae92ef8a4424 ("PATCH] flush icache in correct context") added a "set_fs(KERNEL_DS)" around the flush_icache_range call in the module loader, because apparently m68k assumed user pointers. This series first cleans up the cacheflush implementations, largely by switching as much as possible to the asm-generic version after a few preparations, then moves the misnamed current flush_icache_user_range to a new name, to finally introduce a real flush_icache_user_range to be use= d for the above use cases to flush the instruction cache for a userspace address range. The last patch then drops the set_fs in the module code and moves it into the m68k implementation. A git tree is available here: git://git.infradead.org/users/hch/misc.git flush_icache_range Gitweb: http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/flush= _icache_range