linux-kernel - [PATCH v2 3/5] arm: Use the generic devmem_is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200709211925.1926557-4-palmer@dabbelt.com>
Date:   Thu,  9 Jul 2020 14:19:23 -0700
From:   Palmer Dabbelt <palmer@...belt.com>
To:     zong.li@...ive.com, linux-riscv@...ts.infradead.org,
        rppt@...ux.ibm.com
Cc:     linux@...linux.org.uk, catalin.marinas@....com, will@...nel.org,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>, aou@...s.berkeley.edu,
        gxt@....edu.cn, Arnd Bergmann <arnd@...db.de>,
        linus.walleij@...aro.org, akpm@...ux-foundation.org,
        mchehab+samsung@...nel.org, gregory.0xf0@...il.com,
        masahiroy@...nel.org, Nick Desaulniers <ndesaulniers@...gle.com>,
        bgolaszewski@...libre.com, steve@....org, tglx@...utronix.de,
        keescook@...omium.org, alex@...ti.fr, mcgrof@...nel.org,
        mark.rutland@....com, james.morse@....com,
        alex.shi@...ux.alibaba.com, andriy.shevchenko@...ux.intel.com,
        broonie@...nel.org, rdunlap@...radead.org, davem@...emloft.net,
        rostedt@...dmis.org, dan.j.williams@...el.com, mhiramat@...nel.org,
        krzk@...nel.org, zaslonko@...ux.ibm.com,
        matti.vaittinen@...rohmeurope.com, uwe@...ine-koenig.org,
        clabbe@...libre.com, changbin.du@...el.com,
        Greg KH <gregkh@...uxfoundation.org>, paulmck@...nel.org,
        pmladek@...e.com, brendanhiggins@...gle.com, glider@...gle.com,
        elver@...gle.com, davidgow@...gle.com, ardb@...nel.org,
        takahiro.akashi@...aro.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-riscv@...ts.infradead.org,
        linux-arch@...r.kernel.org, kernel-team@...roid.com,
        Palmer Dabbelt <palmerdabbelt@...gle.com>
Subject: [PATCH v2 3/5] arm: Use the generic devmem_is_allowed()

From: Palmer Dabbelt <palmerdabbelt@...gle.com>

This is exactly the same as the arm64 version, which I recently copied
into lib/ for use by the RISC-V port.

[I haven't even build tested this.  The lib/ patch is on riscv/for-next,
which I'm targeting for 5.9, so this won't work alone.  See the cover
letter for more details.]

Signed-off-by: Palmer Dabbelt <palmerdabbelt@...gle.com>
---
 arch/arm/Kconfig          |  2 +-
 arch/arm/include/asm/io.h |  1 -
 arch/arm/mm/mmap.c        | 22 ----------------------
 3 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2ac74904a3ce..da0f88f6c196 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -5,7 +5,6 @@ config ARM
 	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
-	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
@@ -54,6 +53,7 @@ config ARM
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
+	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index ab2b654084fa..fc748122f1e0 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -441,7 +441,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
 extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
-extern int devmem_is_allowed(unsigned long pfn);
 #endif
 
 /*
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index b8d912ac9e61..a0f8a0ca0788 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -165,25 +165,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
 {
 	return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));
 }
-
-#ifdef CONFIG_STRICT_DEVMEM
-
-#include <linux/ioport.h>
-
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain
- * address is valid. The argument is a physical page number.
- * We mimic x86 here by disallowing access to system RAM as well as
- * device-exclusive MMIO regions. This effectively disable read()/write()
- * on /dev/mem.
- */
-int devmem_is_allowed(unsigned long pfn)
-{
-	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
-		return 0;
-	if (!page_is_ram(pfn))
-		return 1;
-	return 0;
-}
-
-#endif
-- 
2.27.0.383.g050319c2ae-goog