From 46ed99d1b7c92920ce9e313152522847647aae4f Mon Sep 17 00:00:00 2001 From: Emil Goode Date: Sun, 1 Apr 2012 20:48:04 +0200 Subject: x86: vsyscall: Use NULL instead 0 for a pointer argument This patch silences the following sparse warning: arch/x86/kernel/vsyscall_64.c:250:34: warning: Using plain integer as NULL pointer Signed-off-by: Emil Goode Acked-by: Andy Lutomirski Cc: john.stultz@linaro.org Link: http://lkml.kernel.org/r/1333306084-3776-1-git-send-email-emilgoode@gmail.com Signed-off-by: Thomas Gleixner --- arch/x86/kernel/vsyscall_64.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index f386dc49f988..7515cf0e1805 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -216,9 +216,9 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address) current_thread_info()->sig_on_uaccess_error = 1; /* - * 0 is a valid user pointer (in the access_ok sense) on 32-bit and + * NULL is a valid user pointer (in the access_ok sense) on 32-bit and * 64-bit, so we don't need to special-case it here. For all the - * vsyscalls, 0 means "don't write anything" not "write it at + * vsyscalls, NULL means "don't write anything" not "write it at * address 0". */ ret = -EFAULT; @@ -247,7 +247,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address) ret = sys_getcpu((unsigned __user *)regs->di, (unsigned __user *)regs->si, - 0); + NULL); break; } -- cgit v1.2.3 From 2ca052a3710fac208eee690faefdeb8bbd4586a1 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 2 Apr 2012 16:15:33 -0700 Subject: x86: Use correct byte-sized register constraint in __xchg_op() x86-64 can access the low half of any register, but i386 can only do it with a subset of registers. 'r' causes compilation failures on i386, but 'q' expresses the constraint properly. Signed-off-by: Jeremy Fitzhardinge Link: http://lkml.kernel.org/r/4F7A3315.501@goop.org Reported-by: Leigh Scott Tested-by: Thomas Reitmayr Signed-off-by: H. Peter Anvin Cc: v3.3 --- arch/x86/include/asm/cmpxchg.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index b3b733262909..bc18d0ed459a 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -43,7 +43,7 @@ extern void __add_wrong_size(void) switch (sizeof(*(ptr))) { \ case __X86_CASE_B: \ asm volatile (lock #op "b %b0, %1\n" \ - : "+r" (__ret), "+m" (*(ptr)) \ + : "+q" (__ret), "+m" (*(ptr)) \ : : "memory", "cc"); \ break; \ case __X86_CASE_W: \ -- cgit v1.2.3 From 8c91c5325e107ec17e40a59a47c6517387d64eb7 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 6 Apr 2012 09:30:57 -0700 Subject: x86: Use correct byte-sized register constraint in __add() Similar to: 2ca052a x86: Use correct byte-sized register constraint in __xchg_op() ... the __add() macro also needs to use a "q" constraint in the byte-sized case, lest we try to generate an illegal register. Link: http://lkml.kernel.org/r/4F7A3315.501@goop.org Signed-off-by: H. Peter Anvin Cc: Jeremy Fitzhardinge Cc: Leigh Scott Cc: Thomas Reitmayr Cc: v3.3 --- arch/x86/include/asm/cmpxchg.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h index bc18d0ed459a..99480e55973d 100644 --- a/arch/x86/include/asm/cmpxchg.h +++ b/arch/x86/include/asm/cmpxchg.h @@ -173,7 +173,7 @@ extern void __add_wrong_size(void) switch (sizeof(*(ptr))) { \ case __X86_CASE_B: \ asm volatile (lock "addb %b1, %0\n" \ - : "+m" (*(ptr)) : "ri" (inc) \ + : "+m" (*(ptr)) : "qi" (inc) \ : "memory", "cc"); \ break; \ case __X86_CASE_W: \ -- cgit v1.2.3 From 3cb42092ff02edec34bf936b7400b1f1efc8ca43 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 9 Apr 2012 13:59:00 -0400 Subject: um: fix linker script generation while we can't just use -U$(SUBARCH), we still need to kill idiotic define (implicit -Di386=1), both for SUBARCH=i386 and SUBARCH=x86/CONFIG_64BIT=n builds. Signed-off-by: Al Viro --- arch/um/kernel/Makefile | 7 ++++--- arch/x86/Makefile.um | 3 +++ 2 files changed, 7 insertions(+), 3 deletions(-) (limited to 'arch/x86') diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile index 492bc4c1b62b..65a1c3d690ea 100644 --- a/arch/um/kernel/Makefile +++ b/arch/um/kernel/Makefile @@ -3,9 +3,10 @@ # Licensed under the GPL # -CPPFLAGS_vmlinux.lds := -DSTART=$(LDS_START) \ - -DELF_ARCH=$(LDS_ELF_ARCH) \ - -DELF_FORMAT=$(LDS_ELF_FORMAT) +CPPFLAGS_vmlinux.lds := -DSTART=$(LDS_START) \ + -DELF_ARCH=$(LDS_ELF_ARCH) \ + -DELF_FORMAT=$(LDS_ELF_FORMAT) \ + $(LDS_EXTRA) extra-y := vmlinux.lds clean-files := diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um index 4be406abeefd..36b62bc52638 100644 --- a/arch/x86/Makefile.um +++ b/arch/x86/Makefile.um @@ -14,6 +14,9 @@ LINK-y += $(call cc-option,-m32) export LDFLAGS +LDS_EXTRA := -Ui386 +export LDS_EXTRA + # First of all, tune CFLAGS for the specific CPU. This actually sets cflags-y. include $(srctree)/arch/x86/Makefile_32.cpu -- cgit v1.2.3 From a3a85a763c399c0bf483a30d82d2d613e6f94cd3 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Thu, 29 Mar 2012 18:47:46 +0200 Subject: um: Disintegrate asm/system.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Richard Weinberger Reported-by: Toralf Förster CC: dhowells@redhat.com --- arch/um/drivers/mconsole_kern.c | 1 + arch/um/include/asm/Kbuild | 2 +- arch/x86/um/asm/barrier.h | 75 ++++++++++++++++++++++ arch/x86/um/asm/switch_to.h | 7 +++ arch/x86/um/asm/system.h | 135 ---------------------------------------- 5 files changed, 84 insertions(+), 136 deletions(-) create mode 100644 arch/x86/um/asm/barrier.h create mode 100644 arch/x86/um/asm/switch_to.h delete mode 100644 arch/x86/um/asm/system.h (limited to 'arch/x86') diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index e672bd6d43e3..43b39d61b538 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "init.h" #include "irq_kern.h" diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index 8419f5cf2ac7..bb5d6e68829b 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -1,3 +1,3 @@ generic-y += bug.h cputime.h device.h emergency-restart.h futex.h hardirq.h generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h -generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h +generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h diff --git a/arch/x86/um/asm/barrier.h b/arch/x86/um/asm/barrier.h new file mode 100644 index 000000000000..7d01b8c56c00 --- /dev/null +++ b/arch/x86/um/asm/barrier.h @@ -0,0 +1,75 @@ +#ifndef _ASM_UM_BARRIER_H_ +#define _ASM_UM_BARRIER_H_ + +#include +#include +#include +#include +#include + +#include +#include + +/* + * Force strict CPU ordering. + * And yes, this is required on UP too when we're talking + * to devices. + */ +#ifdef CONFIG_X86_32 + +#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) +#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) +#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) + +#else /* CONFIG_X86_32 */ + +#define mb() asm volatile("mfence" : : : "memory") +#define rmb() asm volatile("lfence" : : : "memory") +#define wmb() asm volatile("sfence" : : : "memory") + +#endif /* CONFIG_X86_32 */ + +#define read_barrier_depends() do { } while (0) + +#ifdef CONFIG_SMP + +#define smp_mb() mb() +#ifdef CONFIG_X86_PPRO_FENCE +#define smp_rmb() rmb() +#else /* CONFIG_X86_PPRO_FENCE */ +#define smp_rmb() barrier() +#endif /* CONFIG_X86_PPRO_FENCE */ + +#ifdef CONFIG_X86_OOSTORE +#define smp_wmb() wmb() +#else /* CONFIG_X86_OOSTORE */ +#define smp_wmb() barrier() +#endif /* CONFIG_X86_OOSTORE */ + +#define smp_read_barrier_depends() read_barrier_depends() +#define set_mb(var, value) do { (void)xchg(&var, value); } while (0) + +#else /* CONFIG_SMP */ + +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#define smp_read_barrier_depends() do { } while (0) +#define set_mb(var, value) do { var = value; barrier(); } while (0) + +#endif /* CONFIG_SMP */ + +/* + * Stop RDTSC speculation. This is needed when you need to use RDTSC + * (or get_cycles or vread that possibly accesses the TSC) in a defined + * code region. + * + * (Could use an alternative three way for this if there was one.) + */ +static inline void rdtsc_barrier(void) +{ + alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC); + alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC); +} + +#endif diff --git a/arch/x86/um/asm/switch_to.h b/arch/x86/um/asm/switch_to.h new file mode 100644 index 000000000000..cf97d20da61f --- /dev/null +++ b/arch/x86/um/asm/switch_to.h @@ -0,0 +1,7 @@ +#ifndef _ASM_UM_SWITCH_TO_H_ +#define _ASM_UM_SWITCH_TO_H_ + +extern void *_switch_to(void *prev, void *next, void *last); +#define switch_to(prev, next, last) prev = _switch_to(prev, next, last) + +#endif diff --git a/arch/x86/um/asm/system.h b/arch/x86/um/asm/system.h deleted file mode 100644 index a459fd9b7598..000000000000 --- a/arch/x86/um/asm/system.h +++ /dev/null @@ -1,135 +0,0 @@ -#ifndef _ASM_X86_SYSTEM_H_ -#define _ASM_X86_SYSTEM_H_ - -#include -#include -#include -#include -#include - -#include -#include - -/* entries in ARCH_DLINFO: */ -#ifdef CONFIG_IA32_EMULATION -# define AT_VECTOR_SIZE_ARCH 2 -#else -# define AT_VECTOR_SIZE_ARCH 1 -#endif - -extern unsigned long arch_align_stack(unsigned long sp); - -void default_idle(void); - -/* - * Force strict CPU ordering. - * And yes, this is required on UP too when we're talking - * to devices. - */ -#ifdef CONFIG_X86_32 -/* - * Some non-Intel clones support out of order store. wmb() ceases to be a - * nop for these. - */ -#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) -#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) -#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) -#else -#define mb() asm volatile("mfence":::"memory") -#define rmb() asm volatile("lfence":::"memory") -#define wmb() asm volatile("sfence" ::: "memory") -#endif - -/** - * read_barrier_depends - Flush all pending reads that subsequents reads - * depend on. - * - * No data-dependent reads from memory-like regions are ever reordered - * over this barrier. All reads preceding this primitive are guaranteed - * to access memory (but not necessarily other CPUs' caches) before any - * reads following this primitive that depend on the data return by - * any of the preceding reads. This primitive is much lighter weight than - * rmb() on most CPUs, and is never heavier weight than is - * rmb(). - * - * These ordering constraints are respected by both the local CPU - * and the compiler. - * - * Ordering is not guaranteed by anything other than these primitives, - * not even by data dependencies. See the documentation for - * memory_barrier() for examples and URLs to more information. - * - * For example, the following code would force ordering (the initial - * value of "a" is zero, "b" is one, and "p" is "&a"): - * - * - * CPU 0 CPU 1 - * - * b = 2; - * memory_barrier(); - * p = &b; q = p; - * read_barrier_depends(); - * d = *q; - * - * - * because the read of "*q" depends on the read of "p" and these - * two reads are separated by a read_barrier_depends(). However, - * the following code, with the same initial values for "a" and "b": - * - * - * CPU 0 CPU 1 - * - * a = 2; - * memory_barrier(); - * b = 3; y = b; - * read_barrier_depends(); - * x = a; - * - * - * does not enforce ordering, since there is no data dependency between - * the read of "a" and the read of "b". Therefore, on some CPUs, such - * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() - * in cases like this where there are no data dependencies. - **/ - -#define read_barrier_depends() do { } while (0) - -#ifdef CONFIG_SMP -#define smp_mb() mb() -#ifdef CONFIG_X86_PPRO_FENCE -# define smp_rmb() rmb() -#else -# define smp_rmb() barrier() -#endif -#ifdef CONFIG_X86_OOSTORE -# define smp_wmb() wmb() -#else -# define smp_wmb() barrier() -#endif -#define smp_read_barrier_depends() read_barrier_depends() -#define set_mb(var, value) do { (void)xchg(&var, value); } while (0) -#else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while (0) -#define set_mb(var, value) do { var = value; barrier(); } while (0) -#endif - -/* - * Stop RDTSC speculation. This is needed when you need to use RDTSC - * (or get_cycles or vread that possibly accesses the TSC) in a defined - * code region. - * - * (Could use an alternative three way for this if there was one.) - */ -static inline void rdtsc_barrier(void) -{ - alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC); - alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC); -} - -extern void *_switch_to(void *prev, void *next, void *last); -#define switch_to(prev, next, last) prev = _switch_to(prev, next, last) - -#endif -- cgit v1.2.3 From 76b278edd99fb55525fcf2706095e388bd3d122c Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Thu, 29 Mar 2012 19:10:42 +0200 Subject: um: Use asm-generic/switch_to.h Signed-off-by: Richard Weinberger --- arch/um/include/asm/Kbuild | 1 + arch/um/kernel/process.c | 6 +----- arch/x86/um/asm/switch_to.h | 7 ------- 3 files changed, 2 insertions(+), 12 deletions(-) delete mode 100644 arch/x86/um/asm/switch_to.h (limited to 'arch/x86') diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index bb5d6e68829b..fff24352255d 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -1,3 +1,4 @@ generic-y += bug.h cputime.h device.h emergency-restart.h futex.h hardirq.h generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h +generic-y += switch_to.h diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index f386d04a84a5..2b73dedb44ca 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -88,11 +88,8 @@ static inline void set_current(struct task_struct *task) extern void arch_switch_to(struct task_struct *to); -void *_switch_to(void *prev, void *next, void *last) +void *__switch_to(struct task_struct *from, struct task_struct *to) { - struct task_struct *from = prev; - struct task_struct *to = next; - to->thread.prev_sched = from; set_current(to); @@ -111,7 +108,6 @@ void *_switch_to(void *prev, void *next, void *last) } while (current->thread.saved_task); return current->thread.prev_sched; - } void interrupt_end(void) diff --git a/arch/x86/um/asm/switch_to.h b/arch/x86/um/asm/switch_to.h deleted file mode 100644 index cf97d20da61f..000000000000 --- a/arch/x86/um/asm/switch_to.h +++ /dev/null @@ -1,7 +0,0 @@ -#ifndef _ASM_UM_SWITCH_TO_H_ -#define _ASM_UM_SWITCH_TO_H_ - -extern void *_switch_to(void *prev, void *next, void *last); -#define switch_to(prev, next, last) prev = _switch_to(prev, next, last) - -#endif -- cgit v1.2.3 From f19a0c2c2e6add90b7d6a1b7595abebfe2e4c37a Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Mon, 9 Apr 2012 17:38:35 +0300 Subject: KVM: PMU emulation: GLOBAL_CTRL MSR should be enabled on reset On reset all MPU counters should be enabled in GLOBAL_CTRL MSR. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- arch/x86/kvm/pmu.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 173df38dbda5..2e88438ffd83 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -459,17 +459,17 @@ void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu) pmu->available_event_types = ~entry->ebx & ((1ull << bitmap_len) - 1); if (pmu->version == 1) { - pmu->global_ctrl = (1 << pmu->nr_arch_gp_counters) - 1; - return; + pmu->nr_arch_fixed_counters = 0; + } else { + pmu->nr_arch_fixed_counters = min((int)(entry->edx & 0x1f), + X86_PMC_MAX_FIXED); + pmu->counter_bitmask[KVM_PMC_FIXED] = + ((u64)1 << ((entry->edx >> 5) & 0xff)) - 1; } - pmu->nr_arch_fixed_counters = min((int)(entry->edx & 0x1f), - X86_PMC_MAX_FIXED); - pmu->counter_bitmask[KVM_PMC_FIXED] = - ((u64)1 << ((entry->edx >> 5) & 0xff)) - 1; - pmu->global_ctrl_mask = ~(((1 << pmu->nr_arch_gp_counters) - 1) - | (((1ull << pmu->nr_arch_fixed_counters) - 1) - << X86_PMC_IDX_FIXED)); + pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) | + (((1ull << pmu->nr_arch_fixed_counters) - 1) << X86_PMC_IDX_FIXED); + pmu->global_ctrl_mask = ~pmu->global_ctrl; } void kvm_pmu_init(struct kvm_vcpu *vcpu) -- cgit v1.2.3 From 92ae03f2ef99fbc23bfa9080d6b58f25227bd7ef Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 6 Apr 2012 14:32:32 -0700 Subject: x86: merge 32/64-bit versions of 'strncpy_from_user()' and speed it up This merges the 32- and 64-bit versions of the x86 strncpy_from_user() by just rewriting it in C rather than the ancient inline asm versions that used lodsb/stosb and had been duplicated for (trivial) differences between the 32-bit and 64-bit versions. While doing that, it also speeds them up by doing the accesses a word at a time. Finally, the new routines also properly handle the case of hitting the end of the address space, which we have never done correctly before (fs/namei.c has a hack around it for that reason). Despite all these improvements, it actually removes more lines than it adds, due to the de-duplication. Also, we no longer export (or define) the legacy __strncpy_from_user() function (that was defined to not do the user permission checks), since it's not actually used anywhere, and the user address space checks are built in to the new code. Other architecture maintainers have been notified that the old hack in fs/namei.c will be going away in the 3.5 merge window, in case they copied the x86 approach of being a bit cavalier about the end of the address space. Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar Cc: Peter Anvin" Signed-off-by: Linus Torvalds --- arch/x86/include/asm/uaccess.h | 2 + arch/x86/include/asm/uaccess_32.h | 5 -- arch/x86/include/asm/uaccess_64.h | 4 -- arch/x86/lib/usercopy.c | 103 ++++++++++++++++++++++++++++++++++++++ arch/x86/lib/usercopy_32.c | 87 -------------------------------- arch/x86/lib/usercopy_64.c | 49 ------------------ 6 files changed, 105 insertions(+), 145 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 8be5f54d9360..e0544597cfe7 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -557,6 +557,8 @@ struct __large_struct { unsigned long buf[100]; }; extern unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n); +extern __must_check long +strncpy_from_user(char *dst, const char __user *src, long count); /* * movsl can be slow when source and dest are not both 8-byte aligned diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 566e803cc602..8084bc73b18c 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -213,11 +213,6 @@ static inline unsigned long __must_check copy_from_user(void *to, return n; } -long __must_check strncpy_from_user(char *dst, const char __user *src, - long count); -long __must_check __strncpy_from_user(char *dst, - const char __user *src, long count); - /** * strlen_user: - Get the size of a string in user space. * @str: The string to measure. diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 1c66d30971ad..fcd4b6f3ef02 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -208,10 +208,6 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size) } } -__must_check long -strncpy_from_user(char *dst, const char __user *src, long count); -__must_check long -__strncpy_from_user(char *dst, const char __user *src, long count); __must_check long strnlen_user(const char __user *str, long n); __must_check long __strnlen_user(const char __user *str, long n); __must_check long strlen_user(const char __user *str); diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 97be9cb54483..57252c928f56 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -7,6 +7,8 @@ #include #include +#include + /* * best effort, GUP based copy_from_user() that is NMI-safe */ @@ -41,3 +43,104 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) return len; } EXPORT_SYMBOL_GPL(copy_from_user_nmi); + +static inline unsigned long count_bytes(unsigned long mask) +{ + mask = (mask - 1) & ~mask; + mask >>= 7; + return count_masked_bytes(mask); +} + +/* + * Do a strncpy, return length of string without final '\0'. + * 'count' is the user-supplied count (return 'count' if we + * hit it), 'max' is the address space maximum (and we return + * -EFAULT if we hit it). + */ +static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, long max) +{ + long res = 0; + + /* + * Truncate 'max' to the user-specified limit, so that + * we only have one limit we need to check in the loop + */ + if (max > count) + max = count; + + while (max >= sizeof(unsigned long)) { + unsigned long c; + + /* Fall back to byte-at-a-time if we get a page fault */ + if (unlikely(__get_user(c,(unsigned long __user *)(src+res)))) + break; + /* This can write a few bytes past the NUL character, but that's ok */ + *(unsigned long *)(dst+res) = c; + c = has_zero(c); + if (c) + return res + count_bytes(c); + res += sizeof(unsigned long); + max -= sizeof(unsigned long); + } + + while (max) { + char c; + + if (unlikely(__get_user(c,src+res))) + return -EFAULT; + dst[res] = c; + if (!c) + return res; + res++; + max--; + } + + /* + * Uhhuh. We hit 'max'. But was that the user-specified maximum + * too? If so, that's ok - we got as much as the user asked for. + */ + if (res >= count) + return count; + + /* + * Nope: we hit the address space limit, and we still had more + * characters the caller would have wanted. That's an EFAULT. + */ + return -EFAULT; +} + +/** + * strncpy_from_user: - Copy a NUL terminated string from userspace. + * @dst: Destination address, in kernel space. This buffer must be at + * least @count bytes long. + * @src: Source address, in user space. + * @count: Maximum number of bytes to copy, including the trailing NUL. + * + * Copies a NUL-terminated string from userspace to kernel space. + * + * On success, returns the length of the string (not including the trailing + * NUL). + * + * If access to userspace fails, returns -EFAULT (some data may have been + * copied). + * + * If @count is smaller than the length of the string, copies @count bytes + * and returns @count. + */ +long +strncpy_from_user(char *dst, const char __user *src, long count) +{ + unsigned long max_addr, src_addr; + + if (unlikely(count <= 0)) + return 0; + + max_addr = current_thread_info()->addr_limit.seg; + src_addr = (unsigned long)src; + if (likely(src_addr < max_addr)) { + unsigned long max = max_addr - src_addr; + return do_strncpy_from_user(dst, src, count, max); + } + return -EFAULT; +} +EXPORT_SYMBOL(strncpy_from_user); diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c index d9b094ca7aaa..ef2a6a5d78e3 100644 --- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -32,93 +32,6 @@ static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned lon #define movsl_is_ok(a1, a2, n) \ __movsl_is_ok((unsigned long)(a1), (unsigned long)(a2), (n)) -/* - * Copy a null terminated string from userspace. - */ - -#define __do_strncpy_from_user(dst, src, count, res) \ -do { \ - int __d0, __d1, __d2; \ - might_fault(); \ - __asm__ __volatile__( \ - " testl %1,%1\n" \ - " jz 2f\n" \ - "0: lodsb\n" \ - " stosb\n" \ - " testb %%al,%%al\n" \ - " jz 1f\n" \ - " decl %1\n" \ - " jnz 0b\n" \ - "1: subl %1,%0\n" \ - "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: movl %5,%0\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE(0b,3b) \ - : "=&d"(res), "=&c"(count), "=&a" (__d0), "=&S" (__d1), \ - "=&D" (__d2) \ - : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \ - : "memory"); \ -} while (0) - -/** - * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking. - * @dst: Destination address, in kernel space. This buffer must be at - * least @count bytes long. - * @src: Source address, in user space. - * @count: Maximum number of bytes to copy, including the trailing NUL. - * - * Copies a NUL-terminated string from userspace to kernel space. - * Caller must check the specified block with access_ok() before calling - * this function. - * - * On success, returns the length of the string (not including the trailing - * NUL). - * - * If access to userspace fails, returns -EFAULT (some data may have been - * copied). - * - * If @count is smaller than the length of the string, copies @count bytes - * and returns @count. - */ -long -__strncpy_from_user(char *dst, const char __user *src, long count) -{ - long res; - __do_strncpy_from_user(dst, src, count, res); - return res; -} -EXPORT_SYMBOL(__strncpy_from_user); - -/** - * strncpy_from_user: - Copy a NUL terminated string from userspace. - * @dst: Destination address, in kernel space. This buffer must be at - * least @count bytes long. - * @src: Source address, in user space. - * @count: Maximum number of bytes to copy, including the trailing NUL. - * - * Copies a NUL-terminated string from userspace to kernel space. - * - * On success, returns the length of the string (not including the trailing - * NUL). - * - * If access to userspace fails, returns -EFAULT (some data may have been - * copied). - * - * If @count is smaller than the length of the string, copies @count bytes - * and returns @count. - */ -long -strncpy_from_user(char *dst, const char __user *src, long count) -{ - long res = -EFAULT; - if (access_ok(VERIFY_READ, src, 1)) - __do_strncpy_from_user(dst, src, count, res); - return res; -} -EXPORT_SYMBOL(strncpy_from_user); - /* * Zero Userspace */ diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index b7c2849ffb66..0d0326f388c0 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -8,55 +8,6 @@ #include #include -/* - * Copy a null terminated string from userspace. - */ - -#define __do_strncpy_from_user(dst,src,count,res) \ -do { \ - long __d0, __d1, __d2; \ - might_fault(); \ - __asm__ __volatile__( \ - " testq %1,%1\n" \ - " jz 2f\n" \ - "0: lodsb\n" \ - " stosb\n" \ - " testb %%al,%%al\n" \ - " jz 1f\n" \ - " decq %1\n" \ - " jnz 0b\n" \ - "1: subq %1,%0\n" \ - "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: movq %5,%0\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE(0b,3b) \ - : "=&r"(res), "=&c"(count), "=&a" (__d0), "=&S" (__d1), \ - "=&D" (__d2) \ - : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \ - : "memory"); \ -} while (0) - -long -__strncpy_from_user(char *dst, const char __user *src, long count) -{ - long res; - __do_strncpy_from_user(dst, src, count, res); - return res; -} -EXPORT_SYMBOL(__strncpy_from_user); - -long -strncpy_from_user(char *dst, const char __user *src, long count) -{ - long res = -EFAULT; - if (access_ok(VERIFY_READ, src, 1)) - return __strncpy_from_user(dst, src, count); - return res; -} -EXPORT_SYMBOL(strncpy_from_user); - /* * Zero Userspace */ -- cgit v1.2.3 From 12e993b89464707398e4209bd99983e376454985 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 15 Apr 2012 17:23:00 -0700 Subject: x86-32: fix up strncpy_from_user() sign error The 'max' range needs to be unsigned, since the size of the user address space is bigger than 2GB. We know that 'count' is positive in 'long' (that is checked in the caller), so we will truncate 'max' down to something that fits in a signed long, but before we actually do that, that comparison needs to be done in unsigned. Bug introduced in commit 92ae03f2ef99 ("x86: merge 32/64-bit versions of 'strncpy_from_user()' and speed it up"). On x86-64 you can't trigger this, since the user address space is much smaller than 63 bits, and on x86-32 it works in practice, since you would seldom hit the strncpy limits anyway. I had actually tested the corner-cases, I had only tested them on x86-64. Besides, I had only worried about the case of a pointer *close* to the end of the address space, rather than really far away from it ;) This also changes the "we hit the user-specified maximum" to return 'res', for the trivial reason that gcc seems to generate better code that way. 'res' and 'count' are the same in that case, so it really doesn't matter which one we return. Signed-off-by: Linus Torvalds --- arch/x86/lib/usercopy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 57252c928f56..d6ae30bbd7bb 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -57,7 +57,7 @@ static inline unsigned long count_bytes(unsigned long mask) * hit it), 'max' is the address space maximum (and we return * -EFAULT if we hit it). */ -static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, long max) +static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max) { long res = 0; @@ -100,7 +100,7 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, long * too? If so, that's ok - we got as much as the user asked for. */ if (res >= count) - return count; + return res; /* * Nope: we hit the address space limit, and we still had more -- cgit v1.2.3 From 6c7b8e82aab75a25581c4d446fc87f96634e9ef9 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 13 Apr 2012 12:24:27 +0900 Subject: x86: Handle failures of parsing immediate operands in the instruction decoder This can happen if the instruction is much longer than the maximum length, or if insn->opnd_bytes is manually changed. This patch also fixes warnings from -Wswitch-default flag. Reported-by: Prashanth Nageshappa Signed-off-by: Masami Hiramatsu Cc: Linus Torvalds Cc: Ananth N Mavinakayanahalli Cc: Jim Keniston Cc: Linux-mm Cc: Oleg Nesterov Cc: Andi Kleen Cc: Christoph Hellwig Cc: Steven Rostedt Cc: Arnaldo Carvalho de Melo Cc: Anton Arapov Cc: Srikar Dronamraju Cc: yrl.pp-manager.tt@hitachi.com Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120413032427.32577.42602.stgit@localhost.localdomain Signed-off-by: Ingo Molnar --- arch/x86/lib/insn.c | 53 ++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 36 insertions(+), 17 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c index 25feb1ae71c5..b1e6c4b2e8eb 100644 --- a/arch/x86/lib/insn.c +++ b/arch/x86/lib/insn.c @@ -379,8 +379,8 @@ err_out: return; } -/* Decode moffset16/32/64 */ -static void __get_moffset(struct insn *insn) +/* Decode moffset16/32/64. Return 0 if failed */ +static int __get_moffset(struct insn *insn) { switch (insn->addr_bytes) { case 2: @@ -397,15 +397,19 @@ static void __get_moffset(struct insn *insn) insn->moffset2.value = get_next(int, insn); insn->moffset2.nbytes = 4; break; + default: /* opnd_bytes must be modified manually */ + goto err_out; } insn->moffset1.got = insn->moffset2.got = 1; + return 1; + err_out: - return; + return 0; } -/* Decode imm v32(Iz) */ -static void __get_immv32(struct insn *insn) +/* Decode imm v32(Iz). Return 0 if failed */ +static int __get_immv32(struct insn *insn) { switch (insn->opnd_bytes) { case 2: @@ -417,14 +421,18 @@ static void __get_immv32(struct insn *insn) insn->immediate.value = get_next(int, insn); insn->immediate.nbytes = 4; break; + default: /* opnd_bytes must be modified manually */ + goto err_out; } + return 1; + err_out: - return; + return 0; } -/* Decode imm v64(Iv/Ov) */ -static void __get_immv(struct insn *insn) +/* Decode imm v64(Iv/Ov), Return 0 if failed */ +static int __get_immv(struct insn *insn) { switch (insn->opnd_bytes) { case 2: @@ -441,15 +449,18 @@ static void __get_immv(struct insn *insn) insn->immediate2.value = get_next(int, insn); insn->immediate2.nbytes = 4; break; + default: /* opnd_bytes must be modified manually */ + goto err_out; } insn->immediate1.got = insn->immediate2.got = 1; + return 1; err_out: - return; + return 0; } /* Decode ptr16:16/32(Ap) */ -static void __get_immptr(struct insn *insn) +static int __get_immptr(struct insn *insn) { switch (insn->opnd_bytes) { case 2: @@ -462,14 +473,17 @@ static void __get_immptr(struct insn *insn) break; case 8: /* ptr16:64 is not exist (no segment) */ - return; + return 0; + default: /* opnd_bytes must be modified manually */ + goto err_out; } insn->immediate2.value = get_next(unsigned short, insn); insn->immediate2.nbytes = 2; insn->immediate1.got = insn->immediate2.got = 1; + return 1; err_out: - return; + return 0; } /** @@ -489,7 +503,8 @@ void insn_get_immediate(struct insn *insn) insn_get_displacement(insn); if (inat_has_moffset(insn->attr)) { - __get_moffset(insn); + if (!__get_moffset(insn)) + goto err_out; goto done; } @@ -517,16 +532,20 @@ void insn_get_immediate(struct insn *insn) insn->immediate2.nbytes = 4; break; case INAT_IMM_PTR: - __get_immptr(insn); + if (!__get_immptr(insn)) + goto err_out; break; case INAT_IMM_VWORD32: - __get_immv32(insn); + if (!__get_immv32(insn)) + goto err_out; break; case INAT_IMM_VWORD: - __get_immv(insn); + if (!__get_immv(insn)) + goto err_out; break; default: - break; + /* Here, insn must have an immediate, but failed */ + goto err_out; } if (inat_has_second_immediate(insn->attr)) { insn->immediate2.value = get_next(char, insn); -- cgit v1.2.3 From 2225fd56049643c1a7d645c0ce9d499d43c7974e Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 18 Apr 2012 15:03:04 +0300 Subject: KVM: VMX: Fix kvm_set_shared_msr() called in preemptible context kvm_set_shared_msr() may not be called in preemptible context, but vmx_set_msr() does so: BUG: using smp_processor_id() in preemptible [00000000] code: qemu-kvm/22713 caller is kvm_set_shared_msr+0x32/0xa0 [kvm] Pid: 22713, comm: qemu-kvm Not tainted 3.4.0-rc3+ #39 Call Trace: [] debug_smp_processor_id+0xe2/0x100 [] kvm_set_shared_msr+0x32/0xa0 [kvm] [] vmx_set_msr+0x28b/0x2d0 [kvm_intel] ... Making kvm_set_shared_msr() work in preemptible is cleaner, but it's used in the fast path. Making two variants is overkill, so this patch just disables preemption around the call. Reported-by: Dave Jones Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ad85adfef843..4ff0ab9bc3c8 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2210,9 +2210,12 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) msr = find_msr_entry(vmx, msr_index); if (msr) { msr->data = data; - if (msr - vmx->guest_msrs < vmx->save_nmsrs) + if (msr - vmx->guest_msrs < vmx->save_nmsrs) { + preempt_disable(); kvm_set_shared_msr(msr->index, msr->data, msr->mask); + preempt_enable(); + } break; } ret = kvm_set_msr_common(vcpu, msr_index, data); -- cgit v1.2.3