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2012-10-09ARM: warnings in arch/arm/include/asm/uaccess.hArnd Bergmann1-2/+2
On NOMMU ARM, the __addr_ok() and __range_ok() macros do not evaluate their arguments, which may lead to harmless build warnings in some code where the variables are not used otherwise. Adding a cast to void gets rid of the warning and does not make any semantic changes. Without this patch, building at91x40_defconfig results in: fs/read_write.c: In function 'rw_copy_check_uvector': fs/read_write.c:684:9: warning: unused variable 'buf' [-Wunused-variable] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-09ARM: 7528/1: uaccess: annotate [__]{get,put}_user functions with might_fault()Will Deacon1-2/+16
The user access functions may generate a fault, resulting in invocation of a handler that may sleep. This patch annotates the accessors with might_fault() so that we print a warning if they are invoked from atomic context and help lockdep keep track of mmap_sem. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-09ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINSRussell King1-13/+27
The {get,put}_user macros don't perform range checking on the provided __user address when !CPU_HAS_DOMAINS. This patch reworks the out-of-line assembly accessors to check the user address against a specified limit, returning -EFAULT if is is out of range. [will: changed get_user register allocation to match put_user] [rmk: fixed building on older ARM architectures] Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09ARM: 7449/1: use generic strnlen_user and strncpy_from_user functionsWill Deacon1-21/+6
This patch implements the word-at-a-time interface for ARM using the same algorithm as x86. We use the fls macro from ARMv5 onwards, where we have a clz instruction available which saves us a mov instruction when targetting Thumb-2. For older CPUs, we use the magic 0x0ff0001 constant. Big-endian configurations make use of the implementation from asm-generic. With this implemented, we can replace our byte-at-a-time strnlen_user and strncpy_from_user functions with the optimised generic versions. Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-28Disintegrate asm/system.h for ARMDavid Howells1-1/+1
Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org
2012-01-25ARM: 7301/1: Rename the T() macro to TUSER() to avoid namespace conflictsCatalin Marinas1-8/+8
This macro is used to generate unprivileged accesses (LDRT/STRT) to user space. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-04ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUsCatalin Marinas1-8/+8
This patch removes the domain switching functionality via the set_fs and __switch_to functions on cores that have a TLS register. Currently, the ioremap and vmalloc areas share the same level 1 page tables and therefore have the same domain (DOMAIN_KERNEL). When the kernel domain is modified from Client to Manager (via the __set_fs or in the __switch_to function), the XN (eXecute Never) bit is overridden and newer CPUs can speculatively prefetch the ioremap'ed memory. Linux performs the kernel domain switching to allow user-specific functions (copy_to/from_user, get/put_user etc.) to access kernel memory. In order for these functions to work with the kernel domain set to Client, the patch modifies the LDRT/STRT and related instructions to the LDR/STR ones. The user pages access rights are also modified for kernel read-only access rather than read/write so that the copy-on-write mechanism still works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register (CPU_32v6K is defined) since writing the TLS value to the high vectors page isn't possible. The user addresses passed to the kernel are checked by the access_ok() function so that they do not point to the kernel space. Tested-by: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-04-21ARM: fix build error in arch/arm/kernel/process.cRussell King1-20/+20
/tmp/ccJ3ssZW.s: Assembler messages: /tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077' This is caused because: .section .data .section .text .section .text .previous does not return us to the .text section, but the .data section; this makes use of .previous dangerous if the ordering of previous sections is not known. Fix up the other users of .previous; .pushsection and .popsection are a safer pairing to use than .section and .previous. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-07-24Thumb-2: Implement the unified arch/arm/lib functionsCatalin Marinas1-2/+5
This patch adds the ARM/Thumb-2 unified support for the arch/arm/lib/* files. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-05-29[ARM] allow for alternative __copy_to_user/__clear_user implementationsNicolas Pitre1-0/+2
This allows for optional alternative implementations of __copy_to_user and __clear_user, with a possible runtime fallback to the standard version when the alternative provides no gain over that standard version. This is done by making the standard __copy_to_user into a weak alias for the symbol __copy_to_user_std. Same thing for __clear_user. Those two functions are particularly good candidates to have alternative implementations for, since they rely on the STRT instruction which has lower performances than STM instructions on some CPU cores such as the ARM1176 and Marvell Feroceon. Signed-off-by: Nicolas Pitre <nico@marvell.com>
2008-11-29[ARM] Remove linux/sched.h from asm/cacheflush.h and asm/uaccess.hRussell King1-1/+2
... and fix those drivers that were incorrectly relying upon that include. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-27[ARM] remove memzero()Russell King1-1/+1
As suggested by Andrew Morton, remove memzero() - it's not supported on other architectures so use of it is a potential build breaking bug. Since the compiler optimizes memset(x,0,n) to __memzero() perfectly well, we don't miss out on the underlying benefits of memzero(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-01[ARM] 5230/1: Replace post-indexed LDRT/STRT in uaccess.hCatalin Marinas1-5/+5
The post-index immediate value is optional if it is 0 and this patch removes it. The reason is to allow such instructions to compile to Thumb-2 where only pre-indexed LDRT/STRT instructions are allowed. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-02[ARM] move include/asm-arm to arch/arm/include/asmRussell King1-0/+444
Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>