From 9ca3f07b869c1fbbdfdac3150019a3e4d2948d8e Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Sun, 24 Dec 2006 01:36:35 +0100 Subject: [ARM] 4070/1: arch/arm/kernel: fix warnings from missing includes Include to fix the warning: arch/arm/kernel/traps.c:647:6: warning: symbol '__readwrite_bug' was not declared. Should it be static? Include to fix the warning: arch/arm/kernel/time.c:42:1: warning: symbol 'rtc_lock' was not declared. Should it be static? Signed-off-by: Ben Dooks Signed-off-by: Russell King --- arch/arm/kernel/time.c | 2 ++ arch/arm/kernel/traps.c | 1 + 2 files changed, 3 insertions(+) (limited to 'arch') diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index 6ff5e3ff6cb5..174cd4900bf9 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -29,6 +29,8 @@ #include #include +#include + #include #include #include diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 042a12982e98..908915675edc 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "ptrace.h" #include "signal.h" -- cgit v1.2.3 From db6ccbb61c1291c8aaefadcc8304444f27eeb88d Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 6 Jan 2007 22:53:48 +0000 Subject: [ARM] Fix kernel-mode undefined instruction aborts If the kernel attempts to execute a CP1 or CP2 instruction and it aborts, and a FP emulator is not loaded, we try to return as if to a user context, instead of the proper kernel context. Since the fault came from kernel mode, we must use the kernel return paths. Signed-off-by: Russell King --- arch/arm/kernel/entry-armv.S | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 2db42b18f53f..8517c3c3eb33 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -436,7 +436,7 @@ __und_usr: usr_entry tst r3, #PSR_T_BIT @ Thumb mode? - bne fpundefinstr @ ignore FP + bne __und_usr_unknown @ ignore FP sub r4, r2, #4 @ @@ -448,7 +448,7 @@ __und_usr: @ 1: ldrt r0, [r4] adr r9, ret_from_exception - adr lr, fpundefinstr + adr lr, __und_usr_unknown @ @ fallthrough to call_fpe @ @@ -476,7 +476,9 @@ __und_usr: * Emulators may wish to make use of the following registers: * r0 = instruction opcode. * r2 = PC+4 + * r9 = normal "successful" return address * r10 = this threads thread_info structure. + * lr = unrecognised instruction return address */ call_fpe: tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27 @@ -545,10 +547,12 @@ do_fpe: .data ENTRY(fp_enter) - .word fpundefinstr + .word no_fp .text -fpundefinstr: +no_fp: mov pc, lr + +__und_usr_unknown: mov r0, sp adr lr, ret_from_exception b do_undefinstr -- cgit v1.2.3 From 6020dff09252e3670a89edb36baaa4afb9b10d15 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 30 Dec 2006 23:17:40 +0000 Subject: [ARM] Resolve fuse and direct-IO failures due to missing cache flushes fuse does not work on ARM due to cache incoherency issues - fuse wants to use get_user_pages() to copy data from the current process into kernel space. However, since this accesses userspace via the kernel mapping, the kernel mapping can be out of date wrt data written to userspace. This can lead to unpredictable behaviour (in the case of fuse) or data corruption for direct-IO. This resolves debian bug #402876 Signed-off-by: Russell King --- arch/arm/mm/flush.c | 39 +++++++++++++++++++++++++++++++++++++++ include/asm-arm/cacheflush.h | 10 ++++++++++ 2 files changed, 49 insertions(+) (limited to 'arch') diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 628348c9f6c5..9df507d36e0b 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -202,3 +202,42 @@ void flush_dcache_page(struct page *page) } } EXPORT_SYMBOL(flush_dcache_page); + +/* + * Flush an anonymous page so that users of get_user_pages() + * can safely access the data. The expected sequence is: + * + * get_user_pages() + * -> flush_anon_page + * memcpy() to/from page + * if written to page, flush_dcache_page() + */ +void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) +{ + unsigned long pfn; + + /* VIPT non-aliasing caches need do nothing */ + if (cache_is_vipt_nonaliasing()) + return; + + /* + * Write back and invalidate userspace mapping. + */ + pfn = page_to_pfn(page); + if (cache_is_vivt()) { + flush_cache_page(vma, vmaddr, pfn); + } else { + /* + * For aliasing VIPT, we can flush an alias of the + * userspace address only. + */ + flush_pfn_alias(pfn, vmaddr); + } + + /* + * Invalidate kernel mapping. No data should be contained + * in this mapping of the page. FIXME: this is overkill + * since we actually ask for a write-back and invalidate. + */ + __cpuc_flush_dcache_page(page_address(page)); +} diff --git a/include/asm-arm/cacheflush.h b/include/asm-arm/cacheflush.h index d51049522cd0..5f531ea03059 100644 --- a/include/asm-arm/cacheflush.h +++ b/include/asm-arm/cacheflush.h @@ -357,6 +357,16 @@ extern void flush_dcache_page(struct page *); extern void __flush_dcache_page(struct address_space *mapping, struct page *page); +#define ARCH_HAS_FLUSH_ANON_PAGE +static inline void flush_anon_page(struct vm_area_struct *vma, + struct page *page, unsigned long vmaddr) +{ + extern void __flush_anon_page(struct vm_area_struct *vma, + struct page *, unsigned long); + if (PageAnon(page)) + __flush_anon_page(vma, page, vmaddr); +} + #define flush_dcache_mmap_lock(mapping) \ write_lock_irq(&(mapping)->tree_lock) #define flush_dcache_mmap_unlock(mapping) \ -- cgit v1.2.3 From e97126cd9056b3b42cdc862ace2ed66f8026f55b Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 8 Jan 2007 19:49:12 +0000 Subject: [ARM] Provide basic printk_clock() implementation Current sched_clock() implementations on ARM cause unbootable kernels with PRINTK_TIME support enabled. To avoid this, provide a basic printk_clock() implementation which avoids sched_clock() being called before the page tables have been set up. Signed-off-by: Russell King --- arch/arm/kernel/time.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch') diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index 174cd4900bf9..3c8cdcfe8d4a 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -87,6 +87,17 @@ unsigned long long __attribute__((weak)) sched_clock(void) return (unsigned long long)jiffies * (1000000000 / HZ); } +/* + * An implementation of printk_clock() independent from + * sched_clock(). This avoids non-bootable kernels when + * printk_clock is enabled. + */ +unsigned long long printk_clock(void) +{ + return (unsigned long long)(jiffies - INITIAL_JIFFIES) * + (1000000000 / HZ); +} + static unsigned long next_rtc_update; /* -- cgit v1.2.3