diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-09-11 19:18:28 +0100 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-09-11 19:18:28 +0100 |
commit | c2172ce2303051764829d4958bd50a11ada0590f (patch) | |
tree | c465594496072249d2ad8ee4642f7c5dcd57e139 | |
parent | a4a5a7379e4ca03c192b732d61e446994eb67bbc (diff) | |
parent | 0b61f2c0f37983c98ed4207f3f5e265938371b68 (diff) | |
download | op-kernel-dev-c2172ce2303051764829d4958bd50a11ada0590f.zip op-kernel-dev-c2172ce2303051764829d4958bd50a11ada0590f.tar.gz |
Merge branch 'uaccess' into fixes
31 files changed, 398 insertions, 139 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 1c50210..a7a2e32 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1700,6 +1700,21 @@ config HIGHPTE consumed by page tables. Setting this option will allow user-space 2nd level page tables to reside in high memory. +config CPU_SW_DOMAIN_PAN + bool "Enable use of CPU domains to implement privileged no-access" + depends on MMU && !ARM_LPAE + default y + help + Increase kernel security by ensuring that normal kernel accesses + are unable to access userspace addresses. This can help prevent + use-after-free bugs becoming an exploitable privilege escalation + by ensuring that magic values (such as LIST_POISON) will always + fault when dereferenced. + + CPUs with low-vector mappings use a best-efforts implementation. + Their lower 1MB needs to remain accessible for the vectors, but + the remainder of userspace will become appropriately inaccessible. + config HW_PERF_EVENTS bool "Enable hardware performance counter support for perf events" depends on PERF_EVENTS diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 4abe572..9007c51 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -445,6 +445,48 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) #endif .endm + .macro uaccess_disable, tmp, isb=1 +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + /* + * Whenever we re-enter userspace, the domains should always be + * set appropriately. + */ + mov \tmp, #DACR_UACCESS_DISABLE + mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register + .if \isb + instr_sync + .endif +#endif + .endm + + .macro uaccess_enable, tmp, isb=1 +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + /* + * Whenever we re-enter userspace, the domains should always be + * set appropriately. + */ + mov \tmp, #DACR_UACCESS_ENABLE + mcr p15, 0, \tmp, c3, c0, 0 + .if \isb + instr_sync + .endif +#endif + .endm + + .macro uaccess_save, tmp +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + mrc p15, 0, \tmp, c3, c0, 0 + str \tmp, [sp, #S_FRAME_SIZE] +#endif + .endm + + .macro uaccess_restore +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + ldr r0, [sp, #S_FRAME_SIZE] + mcr p15, 0, r0, c3, c0, 0 +#endif + .endm + .irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo .macro ret\c, reg #if __LINUX_ARM_ARCH__ < 6 diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h index 6ddbe44..fc8ba16 100644 --- a/arch/arm/include/asm/domain.h +++ b/arch/arm/include/asm/domain.h @@ -12,6 +12,7 @@ #ifndef __ASSEMBLY__ #include <asm/barrier.h> +#include <asm/thread_info.h> #endif /* @@ -34,15 +35,14 @@ */ #ifndef CONFIG_IO_36 #define DOMAIN_KERNEL 0 -#define DOMAIN_TABLE 0 #define DOMAIN_USER 1 #define DOMAIN_IO 2 #else #define DOMAIN_KERNEL 2 -#define DOMAIN_TABLE 2 #define DOMAIN_USER 1 #define DOMAIN_IO 0 #endif +#define DOMAIN_VECTORS 3 /* * Domain types @@ -55,30 +55,65 @@ #define DOMAIN_MANAGER 1 #endif -#define domain_val(dom,type) ((type) << (2*(dom))) +#define domain_mask(dom) ((3) << (2 * (dom))) +#define domain_val(dom,type) ((type) << (2 * (dom))) + +#ifdef CONFIG_CPU_SW_DOMAIN_PAN +#define DACR_INIT \ + (domain_val(DOMAIN_USER, DOMAIN_NOACCESS) | \ + domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ + domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)) +#else +#define DACR_INIT \ + (domain_val(DOMAIN_USER, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ + domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)) +#endif + +#define __DACR_DEFAULT \ + domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT) + +#define DACR_UACCESS_DISABLE \ + (__DACR_DEFAULT | domain_val(DOMAIN_USER, DOMAIN_NOACCESS)) +#define DACR_UACCESS_ENABLE \ + (__DACR_DEFAULT | domain_val(DOMAIN_USER, DOMAIN_CLIENT)) #ifndef __ASSEMBLY__ -#ifdef CONFIG_CPU_USE_DOMAINS +static inline unsigned int get_domain(void) +{ + unsigned int domain; + + asm( + "mrc p15, 0, %0, c3, c0 @ get domain" + : "=r" (domain) + : "m" (current_thread_info()->cpu_domain)); + + return domain; +} + static inline void set_domain(unsigned val) { asm volatile( "mcr p15, 0, %0, c3, c0 @ set domain" - : : "r" (val)); + : : "r" (val) : "memory"); isb(); } +#ifdef CONFIG_CPU_USE_DOMAINS #define modify_domain(dom,type) \ do { \ - struct thread_info *thread = current_thread_info(); \ - unsigned int domain = thread->cpu_domain; \ - domain &= ~domain_val(dom, DOMAIN_MANAGER); \ - thread->cpu_domain = domain | domain_val(dom, type); \ - set_domain(thread->cpu_domain); \ + unsigned int domain = get_domain(); \ + domain &= ~domain_mask(dom); \ + domain = domain | domain_val(dom, type); \ + set_domain(domain); \ } while (0) #else -static inline void set_domain(unsigned val) { } static inline void modify_domain(unsigned dom, unsigned type) { } #endif diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index 5eed828..6795368 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h @@ -22,8 +22,11 @@ #ifdef CONFIG_SMP #define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \ +({ \ + unsigned int __ua_flags; \ smp_mb(); \ prefetchw(uaddr); \ + __ua_flags = uaccess_save_and_enable(); \ __asm__ __volatile__( \ "1: ldrex %1, [%3]\n" \ " " insn "\n" \ @@ -34,12 +37,15 @@ __futex_atomic_ex_table("%5") \ : "=&r" (ret), "=&r" (oldval), "=&r" (tmp) \ : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ - : "cc", "memory") + : "cc", "memory"); \ + uaccess_restore(__ua_flags); \ +}) static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { + unsigned int __ua_flags; int ret; u32 val; @@ -49,6 +55,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, smp_mb(); /* Prefetching cannot fault */ prefetchw(uaddr); + __ua_flags = uaccess_save_and_enable(); __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" "1: ldrex %1, [%4]\n" " teq %1, %2\n" @@ -61,6 +68,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, : "=&r" (ret), "=&r" (val) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) : "cc", "memory"); + uaccess_restore(__ua_flags); smp_mb(); *uval = val; @@ -73,6 +81,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, #include <asm/domain.h> #define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \ +({ \ + unsigned int __ua_flags = uaccess_save_and_enable(); \ __asm__ __volatile__( \ "1: " TUSER(ldr) " %1, [%3]\n" \ " " insn "\n" \ @@ -81,12 +91,15 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, __futex_atomic_ex_table("%5") \ : "=&r" (ret), "=&r" (oldval), "=&r" (tmp) \ : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ - : "cc", "memory") + : "cc", "memory"); \ + uaccess_restore(__ua_flags); \ +}) static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { + unsigned int __ua_flags; int ret = 0; u32 val; @@ -94,6 +107,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, return -EFAULT; preempt_disable(); + __ua_flags = uaccess_save_and_enable(); __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" "1: " TUSER(ldr) " %1, [%4]\n" " teq %1, %2\n" @@ -103,6 +117,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, : "+r" (ret), "=&r" (val) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) : "cc", "memory"); + uaccess_restore(__ua_flags); *uval = val; preempt_enable(); diff --git a/arch/arm/include/asm/pgtable-2level-hwdef.h b/arch/arm/include/asm/pgtable-2level-hwdef.h index 5e68278..d0131ee 100644 --- a/arch/arm/include/asm/pgtable-2level-hwdef.h +++ b/arch/arm/include/asm/pgtable-2level-hwdef.h @@ -23,6 +23,7 @@ #define PMD_PXNTABLE (_AT(pmdval_t, 1) << 2) /* v7 */ #define PMD_BIT4 (_AT(pmdval_t, 1) << 4) #define PMD_DOMAIN(x) (_AT(pmdval_t, (x)) << 5) +#define PMD_DOMAIN_MASK PMD_DOMAIN(0x0f) #define PMD_PROTECTION (_AT(pmdval_t, 1) << 9) /* v5 */ /* * - section diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index bd32ede..ae02e68 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -25,7 +25,6 @@ struct task_struct; #include <asm/types.h> -#include <asm/domain.h> typedef unsigned long mm_segment_t; @@ -74,9 +73,6 @@ struct thread_info { .flags = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ .addr_limit = KERNEL_DS, \ - .cpu_domain = domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_IO, DOMAIN_CLIENT), \ } #define init_thread_info (init_thread_union.thread_info) diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 74b17d0..01bae13 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -50,6 +50,35 @@ struct exception_table_entry extern int fixup_exception(struct pt_regs *regs); /* + * These two functions allow hooking accesses to userspace to increase + * system integrity by ensuring that the kernel can not inadvertantly + * perform such accesses (eg, via list poison values) which could then + * be exploited for priviledge escalation. + */ +static inline unsigned int uaccess_save_and_enable(void) +{ +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + unsigned int old_domain = get_domain(); + + /* Set the current domain access to permit user accesses */ + set_domain((old_domain & ~domain_mask(DOMAIN_USER)) | + domain_val(DOMAIN_USER, DOMAIN_CLIENT)); + + return old_domain; +#else + return 0; +#endif +} + +static inline void uaccess_restore(unsigned int flags) +{ +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + /* Restore the user access mask */ + set_domain(flags); +#endif +} + +/* * These two are intentionally not defined anywhere - if the kernel * code generates any references to them, that's a bug. */ @@ -165,6 +194,7 @@ extern int __get_user_64t_4(void *); register typeof(x) __r2 asm("r2"); \ register unsigned long __l asm("r1") = __limit; \ register int __e asm("r0"); \ + unsigned int __ua_flags = uaccess_save_and_enable(); \ switch (sizeof(*(__p))) { \ case 1: \ if (sizeof((x)) >= 8) \ @@ -192,6 +222,7 @@ extern int __get_user_64t_4(void *); break; \ default: __e = __get_user_bad(); break; \ } \ + uaccess_restore(__ua_flags); \ x = (typeof(*(p))) __r2; \ __e; \ }) @@ -224,6 +255,7 @@ extern int __put_user_8(void *, unsigned long long); register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \ register unsigned long __l asm("r1") = __limit; \ register int __e asm("r0"); \ + unsigned int __ua_flags = uaccess_save_and_enable(); \ switch (sizeof(*(__p))) { \ case 1: \ __put_user_x(__r2, __p, __e, __l, 1); \ @@ -239,6 +271,7 @@ extern int __put_user_8(void *, unsigned long long); break; \ default: __e = __put_user_bad(); break; \ } \ + uaccess_restore(__ua_flags); \ __e; \ }) @@ -300,14 +333,17 @@ static inline void set_fs(mm_segment_t fs) do { \ unsigned long __gu_addr = (unsigned long)(ptr); \ unsigned long __gu_val; \ + unsigned int __ua_flags; \ __chk_user_ptr(ptr); \ might_fault(); \ + __ua_flags = uaccess_save_and_enable(); \ switch (sizeof(*(ptr))) { \ case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \ case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \ case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \ default: (__gu_val) = __get_user_bad(); \ } \ + uaccess_restore(__ua_flags); \ (x) = (__typeof__(*(ptr)))__gu_val; \ } while (0) @@ -381,9 +417,11 @@ do { \ #define __put_user_err(x, ptr, err) \ do { \ unsigned long __pu_addr = (unsigned long)(ptr); \ + unsigned int __ua_flags; \ __typeof__(*(ptr)) __pu_val = (x); \ __chk_user_ptr(ptr); \ might_fault(); \ + __ua_flags = uaccess_save_and_enable(); \ switch (sizeof(*(ptr))) { \ case 1: __put_user_asm_byte(__pu_val, __pu_addr, err); break; \ case 2: __put_user_asm_half(__pu_val, __pu_addr, err); break; \ @@ -391,6 +429,7 @@ do { \ case 8: __put_user_asm_dword(__pu_val, __pu_addr, err); break; \ default: __put_user_bad(); \ } \ + uaccess_restore(__ua_flags); \ } while (0) #define __put_user_asm_byte(x, __pu_addr, err) \ @@ -474,11 +513,46 @@ do { \ #ifdef CONFIG_MMU -extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n); -extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n); -extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n); -extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n); -extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n); +extern unsigned long __must_check +arm_copy_from_user(void *to, const void __user *from, unsigned long n); + +static inline unsigned long __must_check +__copy_from_user(void *to, const void __user *from, unsigned long n) +{ + unsigned int __ua_flags = uaccess_save_and_enable(); + n = arm_copy_from_user(to, from, n); + uaccess_restore(__ua_flags); + return n; +} + +extern unsigned long __must_check +arm_copy_to_user(void __user *to, const void *from, unsigned long n); +extern unsigned long __must_check +__copy_to_user_std(void __user *to, const void *from, unsigned long n); + +static inline unsigned long __must_check +__copy_to_user(void __user *to, const void *from, unsigned long n) +{ + unsigned int __ua_flags = uaccess_save_and_enable(); + n = arm_copy_to_user(to, from, n); + uaccess_restore(__ua_flags); + return n; +} + +extern unsigned long __must_check +arm_clear_user(void __user *addr, unsigned long n); +extern unsigned long __must_check +__clear_user_std(void __user *addr, unsigned long n); + +static inline unsigned long __must_check +__clear_user(void __user *addr, unsigned long n) +{ + unsigned int __ua_flags = uaccess_save_and_enable(); + n = arm_clear_user(addr, n); + uaccess_restore(__ua_flags); + return n; +} + #else #define __copy_from_user(to, from, n) (memcpy(to, (void __force *)from, n), 0) #define __copy_to_user(to, from, n) (memcpy((void __force *)to, from, n), 0) @@ -511,6 +585,7 @@ static inline unsigned long __must_check clear_user(void __user *to, unsigned lo return n; } +/* These are from lib/ code, and use __get_user() and friends */ extern long strncpy_from_user(char *dest, const char __user *src, long count); extern __must_check long strlen_user(const char __user *str); diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 5e5a51a..f89811f 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -97,9 +97,9 @@ EXPORT_SYMBOL(mmiocpy); #ifdef CONFIG_MMU EXPORT_SYMBOL(copy_page); -EXPORT_SYMBOL(__copy_from_user); -EXPORT_SYMBOL(__copy_to_user); -EXPORT_SYMBOL(__clear_user); +EXPORT_SYMBOL(arm_copy_from_user); +EXPORT_SYMBOL(arm_copy_to_user); +EXPORT_SYMBOL(arm_clear_user); EXPORT_SYMBOL(__get_user_1); EXPORT_SYMBOL(__get_user_2); diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index cb4fb1e..3e1c26e 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -149,10 +149,10 @@ ENDPROC(__und_invalid) #define SPFIX(code...) #endif - .macro svc_entry, stack_hole=0, trace=1 + .macro svc_entry, stack_hole=0, trace=1, uaccess=1 UNWIND(.fnstart ) UNWIND(.save {r0 - pc} ) - sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4) + sub sp, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4) #ifdef CONFIG_THUMB2_KERNEL SPFIX( str r0, [sp] ) @ temporarily saved SPFIX( mov r0, sp ) @@ -167,7 +167,7 @@ ENDPROC(__und_invalid) ldmia r0, {r3 - r5} add r7, sp, #S_SP - 4 @ here for interlock avoidance mov r6, #-1 @ "" "" "" "" - add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4) + add r2, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4) SPFIX( addeq r2, r2, #4 ) str r3, [sp, #-4]! @ save the "real" r0 copied @ from the exception stack @@ -185,6 +185,11 @@ ENDPROC(__und_invalid) @ stmia r7, {r2 - r6} + uaccess_save r0 + .if \uaccess + uaccess_disable r0 + .endif + .if \trace #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off @@ -194,7 +199,7 @@ ENDPROC(__und_invalid) .align 5 __dabt_svc: - svc_entry + svc_entry uaccess=0 mov r2, sp dabt_helper THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR @@ -368,7 +373,7 @@ ENDPROC(__fiq_abt) #error "sizeof(struct pt_regs) must be a multiple of 8" #endif - .macro usr_entry, trace=1 + .macro usr_entry, trace=1, uaccess=1 UNWIND(.fnstart ) UNWIND(.cantunwind ) @ don't unwind the user space sub sp, sp, #S_FRAME_SIZE @@ -400,6 +405,10 @@ ENDPROC(__fiq_abt) ARM( stmdb r0, {sp, lr}^ ) THUMB( store_user_sp_lr r0, r1, S_SP - S_PC ) + .if \uaccess + uaccess_disable ip + .endif + @ Enable the alignment trap while in kernel mode ATRAP( teq r8, r7) ATRAP( mcrne p15, 0, r8, c1, c0, 0) @@ -435,7 +444,7 @@ ENDPROC(__fiq_abt) .align 5 __dabt_usr: - usr_entry + usr_entry uaccess=0 kuser_cmpxchg_check mov r2, sp dabt_helper @@ -458,7 +467,7 @@ ENDPROC(__irq_usr) .align 5 __und_usr: - usr_entry + usr_entry uaccess=0 mov r2, r4 mov r3, r5 @@ -484,6 +493,8 @@ __und_usr: 1: ldrt r0, [r4] ARM_BE8(rev r0, r0) @ little endian instruction + uaccess_disable ip + @ r0 = 32-bit ARM instruction which caused the exception @ r2 = PC value for the following instruction (:= regs->ARM_pc) @ r4 = PC value for the faulting instruction @@ -518,9 +529,10 @@ __und_usr_thumb: 2: ldrht r5, [r4] ARM_BE8(rev16 r5, r5) @ little endian instruction cmp r5, #0xe800 @ 32bit instruction if xx != 0 - blo __und_usr_fault_16 @ 16bit undefined instruction + blo __und_usr_fault_16_pan @ 16bit undefined instruction 3: ldrht r0, [r2] ARM_BE8(rev16 r0, r0) @ little endian instruction + uaccess_disable ip add r2, r2, #2 @ r2 is PC + 2, make it PC + 4 str r2, [sp, #S_PC] @ it's a 2x16bit instr, update orr r0, r0, r5, lsl #16 @@ -715,6 +727,8 @@ ENDPROC(no_fp) __und_usr_fault_32: mov r1, #4 b 1f +__und_usr_fault_16_pan: + uaccess_disable ip __und_usr_fault_16: mov r1, #2 1: mov r0, sp @@ -770,6 +784,8 @@ ENTRY(__switch_to) ldr r4, [r2, #TI_TP_VALUE] ldr r5, [r2, #TI_TP_VALUE + 4] #ifdef CONFIG_CPU_USE_DOMAINS + mrc p15, 0, r6, c3, c0, 0 @ Get domain register + str r6, [r1, #TI_CPU_DOMAIN] @ Save old domain register ldr r6, [r2, #TI_CPU_DOMAIN] #endif switch_tls r1, r4, r5, r3, r7 diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index b48dd4f..61974df 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -174,6 +174,8 @@ ENTRY(vector_swi) USER( ldr scno, [lr, #-4] ) @ get SWI instruction #endif + uaccess_disable tbl + adr tbl, sys_call_table @ load syscall table pointer #if defined(CONFIG_OABI_COMPAT) diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S index 1a0045a..0d22ad2 100644 --- a/arch/arm/kernel/entry-header.S +++ b/arch/arm/kernel/entry-header.S @@ -196,7 +196,7 @@ msr cpsr_c, \rtemp @ switch back to the SVC mode .endm -#ifndef CONFIG_THUMB2_KERNEL + .macro svc_exit, rpsr, irq = 0 .if \irq != 0 @ IRQs already off @@ -215,6 +215,10 @@ blne trace_hardirqs_off #endif .endif + uaccess_restore + +#ifndef CONFIG_THUMB2_KERNEL + @ ARM mode SVC restore msr spsr_cxsf, \rpsr #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_32v6K) @ We must avoid clrex due to Cortex-A15 erratum #830321 @@ -222,6 +226,20 @@ strex r1, r2, [r0] @ clear the exclusive monitor #endif ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr +#else + @ Thumb mode SVC restore + ldr lr, [sp, #S_SP] @ top of the stack + ldrd r0, r1, [sp, #S_LR] @ calling lr and pc + + @ We must avoid clrex due to Cortex-A15 erratum #830321 + strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor + + stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context + ldmia sp, {r0 - r12} + mov sp, lr + ldr lr, [sp], #4 + rfeia sp! +#endif .endm @ @@ -241,6 +259,9 @@ @ on the stack remains correct). @ .macro svc_exit_via_fiq + uaccess_restore +#ifndef CONFIG_THUMB2_KERNEL + @ ARM mode restore mov r0, sp ldmib r0, {r1 - r14} @ abort is deadly from here onward (it will @ clobber state restored below) @@ -250,9 +271,27 @@ msr spsr_cxsf, r9 ldr r0, [r0, #S_R0] ldmia r8, {pc}^ +#else + @ Thumb mode restore + add r0, sp, #S_R2 + ldr lr, [sp, #S_LR] + ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will + @ clobber state restored below) + ldmia r0, {r2 - r12} + mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT + msr cpsr_c, r1 + sub r0, #S_R2 + add r8, r0, #S_PC + ldmia r0, {r0 - r1} + rfeia r8 +#endif .endm + .macro restore_user_regs, fast = 0, offset = 0 + uaccess_enable r1, isb=0 +#ifndef CONFIG_THUMB2_KERNEL + @ ARM mode restore mov r2, sp ldr r1, [r2, #\offset + S_PSR] @ get calling cpsr ldr lr, [r2, #\offset + S_PC]! @ get pc @@ -270,72 +309,16 @@ @ after ldm {}^ add sp, sp, #\offset + S_FRAME_SIZE movs pc, lr @ return & move spsr_svc into cpsr - .endm - -#else /* CONFIG_THUMB2_KERNEL */ - .macro svc_exit, rpsr, irq = 0 - .if \irq != 0 - @ IRQs already off -#ifdef CONFIG_TRACE_IRQFLAGS - @ The parent context IRQs must have been enabled to get here in - @ the first place, so there's no point checking the PSR I bit. - bl trace_hardirqs_on -#endif - .else - @ IRQs off again before pulling preserved data off the stack - disable_irq_notrace -#ifdef CONFIG_TRACE_IRQFLAGS - tst \rpsr, #PSR_I_BIT - bleq trace_hardirqs_on - tst \rpsr, #PSR_I_BIT - blne trace_hardirqs_off -#endif - .endif - ldr lr, [sp, #S_SP] @ top of the stack - ldrd r0, r1, [sp, #S_LR] @ calling lr and pc - - @ We must avoid clrex due to Cortex-A15 erratum #830321 - strex r2, r1, [sp, #S_LR] @ clear the exclusive monitor - - stmdb lr!, {r0, r1, \rpsr} @ calling lr and rfe context - ldmia sp, {r0 - r12} - mov sp, lr - ldr lr, [sp], #4 - rfeia sp! - .endm - - @ - @ svc_exit_via_fiq - like svc_exit but switches to FIQ mode before exit - @ - @ For full details see non-Thumb implementation above. - @ - .macro svc_exit_via_fiq - add r0, sp, #S_R2 - ldr lr, [sp, #S_LR] - ldr sp, [sp, #S_SP] @ abort is deadly from here onward (it will - @ clobber state restored below) - ldmia r0, {r2 - r12} - mov r1, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT - msr cpsr_c, r1 - sub r0, #S_R2 - add r8, r0, #S_PC - ldmia r0, {r0 - r1} - rfeia r8 - .endm - -#ifdef CONFIG_CPU_V7M - /* - * Note we don't need to do clrex here as clearing the local monitor is - * part of each exception entry and exit sequence. - */ - .macro restore_user_regs, fast = 0, offset = 0 +#elif defined(CONFIG_CPU_V7M) + @ V7M restore. + @ Note that we don't need to do clrex here as clearing the local + @ monitor is part of the exception entry and exit sequence. .if \offset add sp, #\offset .endif v7m_exception_slow_exit ret_r0 = \fast - .endm -#else /* ifdef CONFIG_CPU_V7M */ - .macro restore_user_regs, fast = 0, offset = 0 +#else + @ Thumb mode restore mov r2, sp load_user_sp_lr r2, r3, \offset + S_SP @ calling sp, lr ldr r1, [sp, #\offset + S_PSR] @ get calling cpsr @@ -353,9 +336,8 @@ .endif add sp, sp, #S_FRAME_SIZE - S_SP movs pc, lr @ return & move spsr_svc into cpsr - .endm -#endif /* ifdef CONFIG_CPU_V7M / else */ #endif /* !CONFIG_THUMB2_KERNEL */ + .endm /* * Context tracking subsystem. Used to instrument transitions diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 29e2991..04286fd 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -464,10 +464,7 @@ __enable_mmu: #ifdef CONFIG_ARM_LPAE mcrr p15, 0, r4, r5, c2 @ load TTBR0 #else - mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_IO, DOMAIN_CLIENT)) + mov r5, #DACR_INIT mcr p15, 0, r5, c3, c0, 0 @ load domain access register mcr p15, 0, r4, c2, c0, 0 @ load page table pointer #endif diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index f192a2a..e550a45 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -129,12 +129,36 @@ void __show_regs(struct pt_regs *regs) buf[4] = '\0'; #ifndef CONFIG_CPU_V7M - printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", - buf, interrupts_enabled(regs) ? "n" : "ff", - fast_interrupts_enabled(regs) ? "n" : "ff", - processor_modes[processor_mode(regs)], - isa_modes[isa_mode(regs)], - get_fs() == get_ds() ? "kernel" : "user"); + { + unsigned int domain = get_domain(); + const char *segment; + +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + /* + * Get the domain register for the parent context. In user + * mode, we don't save the DACR, so lets use what it should + * be. For other modes, we place it after the pt_regs struct. + */ + if (user_mode(regs)) + domain = DACR_UACCESS_ENABLE; + else + domain = *(unsigned int *)(regs + 1); +#endif + + if ((domain & domain_mask(DOMAIN_USER)) == + domain_val(DOMAIN_USER, DOMAIN_NOACCESS)) + segment = "none"; + else if (get_fs() == get_ds()) + segment = "kernel"; + else + segment = "user"; + + printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", + buf, interrupts_enabled(regs) ? "n" : "ff", + fast_interrupts_enabled(regs) ? "n" : "ff", + processor_modes[processor_mode(regs)], + isa_modes[isa_mode(regs)], segment); + } #else printk("xPSR: %08lx\n", regs->ARM_cpsr); #endif @@ -146,10 +170,9 @@ void __show_regs(struct pt_regs *regs) buf[0] = '\0'; #ifdef CONFIG_CPU_CP15_MMU { - unsigned int transbase, dac; + unsigned int transbase, dac = get_domain(); asm("mrc p15, 0, %0, c2, c0\n\t" - "mrc p15, 0, %1, c3, c0\n" - : "=r" (transbase), "=r" (dac)); + : "=r" (transbase)); snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", transbase, dac); } @@ -210,6 +233,16 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start, memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); +#ifdef CONFIG_CPU_USE_DOMAINS + /* + * Copy the initial value of the domain access control register + * from the current thread: thread->addr_limit will have been + * copied from the current thread via setup_thread_stack() in + * kernel/fork.c + */ + thread->cpu_domain = get_domain(); +#endif + if (likely(!(p->flags & PF_KTHREAD))) { *childregs = *current_pt_regs(); childregs->ARM_r0 = 0; diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c index 1361756..5b26e7e 100644 --- a/arch/arm/kernel/swp_emulate.c +++ b/arch/arm/kernel/swp_emulate.c @@ -141,11 +141,14 @@ static int emulate_swpX(unsigned int address, unsigned int *data, while (1) { unsigned long temp; + unsigned int __ua_flags; + __ua_flags = uaccess_save_and_enable(); if (type == TYPE_SWPB) __user_swpb_asm(*data, address, res, temp); else __user_swp_asm(*data, address, res, temp); + uaccess_restore(__ua_flags); if (likely(res != -EAGAIN) || signal_pending(current)) break; diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index d358226..969f9d9 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -870,7 +870,6 @@ void __init early_trap_init(void *vectors_base) kuser_init(vectors_base); flush_icache_range(vectors, vectors + PAGE_SIZE * 2); - modify_domain(DOMAIN_USER, DOMAIN_CLIENT); #else /* ifndef CONFIG_CPU_V7M */ /* * on V7-M there is no need to copy the vector table to a dedicated diff --git a/arch/arm/lib/clear_user.S b/arch/arm/lib/clear_user.S index 1710fd7..970d6c0 100644 --- a/arch/arm/lib/clear_user.S +++ b/arch/arm/lib/clear_user.S @@ -12,14 +12,14 @@ .text -/* Prototype: int __clear_user(void *addr, size_t sz) +/* Prototype: unsigned long arm_clear_user(void *addr, size_t sz) * Purpose : clear some user memory * Params : addr - user memory address to clear * : sz - number of bytes to clear * Returns : number of bytes NOT cleared */ ENTRY(__clear_user_std) -WEAK(__clear_user) +WEAK(arm_clear_user) stmfd sp!, {r1, lr} mov r2, #0 cmp r1, #4 @@ -44,7 +44,7 @@ WEAK(__clear_user) USER( strnebt r2, [r0]) mov r0, #0 ldmfd sp!, {r1, pc} -ENDPROC(__clear_user) +ENDPROC(arm_clear_user) ENDPROC(__clear_user_std) .pushsection .text.fixup,"ax" diff --git a/arch/arm/lib/copy_from_user.S b/arch/arm/lib/copy_from_user.S index 7a235b9..1512beb 100644 --- a/arch/arm/lib/copy_from_user.S +++ b/arch/arm/lib/copy_from_user.S @@ -17,7 +17,7 @@ /* * Prototype: * - * size_t __copy_from_user(void *to, const void *from, size_t n) + * size_t arm_copy_from_user(void *to, const void *from, size_t n) * * Purpose: * @@ -89,11 +89,11 @@ .text -ENTRY(__copy_from_user) +ENTRY(arm_copy_from_user) #include "copy_template.S" -ENDPROC(__copy_from_user) +ENDPROC(arm_copy_from_user) .pushsection .fixup,"ax" .align 0 diff --git a/arch/arm/lib/copy_to_user.S b/arch/arm/lib/copy_to_user.S index 9648b06..caf5019 100644 --- a/arch/arm/lib/copy_to_user.S +++ b/arch/arm/lib/copy_to_user.S @@ -17,7 +17,7 @@ /* * Prototype: * - * size_t __copy_to_user(void *to, const void *from, size_t n) + * size_t arm_copy_to_user(void *to, const void *from, size_t n) * * Purpose: * @@ -93,11 +93,11 @@ .text ENTRY(__copy_to_user_std) -WEAK(__copy_to_user) +WEAK(arm_copy_to_user) #include "copy_template.S" -ENDPROC(__copy_to_user) +ENDPROC(arm_copy_to_user) ENDPROC(__copy_to_user_std) .pushsection .text.fixup,"ax" diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S index 1d0957e..1712f13 100644 --- a/arch/arm/lib/csumpartialcopyuser.S +++ b/arch/arm/lib/csumpartialcopyuser.S @@ -17,6 +17,19 @@ .text +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + .macro save_regs + mrc p15, 0, ip, c3, c0, 0 + stmfd sp!, {r1, r2, r4 - r8, ip, lr} + uaccess_enable ip + .endm + + .macro load_regs + ldmfd sp!, {r1, r2, r4 - r8, ip, lr} + mcr p15, 0, ip, c3, c0, 0 + ret lr + .endm +#else .macro save_regs stmfd sp!, {r1, r2, r4 - r8, lr} .endm @@ -24,6 +37,7 @@ .macro load_regs ldmfd sp!, {r1, r2, r4 - r8, pc} .endm +#endif .macro load1b, reg1 ldrusr \reg1, r0, 1 diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c index 4b39af2..d72b909 100644 --- a/arch/arm/lib/uaccess_with_memcpy.c +++ b/arch/arm/lib/uaccess_with_memcpy.c @@ -136,7 +136,7 @@ out: } unsigned long -__copy_to_user(void __user *to, const void *from, unsigned long n) +arm_copy_to_user(void __user *to, const void *from, unsigned long n) { /* * This test is stubbed out of the main function above to keep @@ -190,7 +190,7 @@ out: return n; } -unsigned long __clear_user(void __user *addr, unsigned long n) +unsigned long arm_clear_user(void __user *addr, unsigned long n) { /* See rational for this in __copy_to_user() above. */ if (n < 64) diff --git a/arch/arm/mm/abort-ev4.S b/arch/arm/mm/abort-ev4.S index 54473cd4..b3b31e3 100644 --- a/arch/arm/mm/abort-ev4.S +++ b/arch/arm/mm/abort-ev4.S @@ -19,6 +19,7 @@ ENTRY(v4_early_abort) mrc p15, 0, r1, c5, c0, 0 @ get FSR mrc p15, 0, r0, c6, c0, 0 @ get FAR ldr r3, [r4] @ read aborted ARM instruction + uaccess_disable ip @ disable userspace access bic r1, r1, #1 << 11 | 1 << 10 @ clear bits 11 and 10 of FSR tst r3, #1 << 20 @ L = 1 -> write? orreq r1, r1, #1 << 11 @ yes. diff --git a/arch/arm/mm/abort-ev5t.S b/arch/arm/mm/abort-ev5t.S index a0908d4..a6a381a 100644 --- a/arch/arm/mm/abort-ev5t.S +++ b/arch/arm/mm/abort-ev5t.S @@ -21,8 +21,10 @@ ENTRY(v5t_early_abort) mrc p15, 0, r0, c6, c0, 0 @ get FAR do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3 ldreq r3, [r4] @ read aborted ARM instruction + uaccess_disable ip @ disable user access bic r1, r1, #1 << 11 @ clear bits 11 of FSR - do_ldrd_abort tmp=ip, insn=r3 + teq_ldrd tmp=ip, insn=r3 @ insn was LDRD? + beq do_DataAbort @ yes tst r3, #1 << 20 @ check write orreq r1, r1, #1 << 11 b do_DataAbort diff --git a/arch/arm/mm/abort-ev5tj.S b/arch/arm/mm/abort-ev5tj.S index 4006b7a..00ab011 100644 --- a/arch/arm/mm/abort-ev5tj.S +++ b/arch/arm/mm/abort-ev5tj.S @@ -24,7 +24,9 @@ ENTRY(v5tj_early_abort) bne do_DataAbort do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3 ldreq r3, [r4] @ read aborted ARM instruction - do_ldrd_abort tmp=ip, insn=r3 + uaccess_disable ip @ disable userspace access + teq_ldrd tmp=ip, insn=r3 @ insn was LDRD? + beq do_DataAbort @ yes tst r3, #1 << 20 @ L = 0 -> write orreq r1, r1, #1 << 11 @ yes. b do_DataAbort diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S index 8c48c5c..8801a15 100644 --- a/arch/arm/mm/abort-ev6.S +++ b/arch/arm/mm/abort-ev6.S @@ -26,16 +26,18 @@ ENTRY(v6_early_abort) ldr ip, =0x4107b36 mrc p15, 0, r3, c0, c0, 0 @ get processor id teq ip, r3, lsr #4 @ r0 ARM1136? - bne do_DataAbort + bne 1f tst r5, #PSR_J_BIT @ Java? tsteq r5, #PSR_T_BIT @ Thumb? - bne do_DataAbort + bne 1f bic r1, r1, #1 << 11 @ clear bit 11 of FSR ldr r3, [r4] @ read aborted ARM instruction ARM_BE8(rev r3, r3) - do_ldrd_abort tmp=ip, insn=r3 + teq_ldrd tmp=ip, insn=r3 @ insn was LDRD? + beq 1f @ yes tst r3, #1 << 20 @ L = 0 -> write orreq r1, r1, #1 << 11 @ yes. #endif +1: uaccess_disable ip @ disable userspace access b do_DataAbort diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S index 4812ad0..e8d0e08 100644 --- a/arch/arm/mm/abort-ev7.S +++ b/arch/arm/mm/abort-ev7.S @@ -15,6 +15,7 @@ ENTRY(v7_early_abort) mrc p15, 0, r1, c5, c0, 0 @ get FSR mrc p15, 0, r0, c6, c0, 0 @ get FAR + uaccess_disable ip @ disable userspace access /* * V6 code adjusts the returned DFSR. diff --git a/arch/arm/mm/abort-lv4t.S b/arch/arm/mm/abort-lv4t.S index f398258..6d8e8e3 100644 --- a/arch/arm/mm/abort-lv4t.S +++ b/arch/arm/mm/abort-lv4t.S @@ -26,6 +26,7 @@ ENTRY(v4t_late_abort) #endif bne .data_thumb_abort ldr r8, [r4] @ read arm instruction + uaccess_disable ip @ disable userspace access tst r8, #1 << 20 @ L = 1 -> write? orreq r1, r1, #1 << 11 @ yes. and r7, r8, #15 << 24 @@ -155,6 +156,7 @@ ENTRY(v4t_late_abort) .data_thumb_abort: ldrh r8, [r4] @ read instruction + uaccess_disable ip @ disable userspace access tst r8, #1 << 11 @ L = 1 -> write? orreq r1, r1, #1 << 8 @ yes and r7, r8, #15 << 12 diff --git a/arch/arm/mm/abort-macro.S b/arch/arm/mm/abort-macro.S index 2cbf68e..4509bee 100644 --- a/arch/arm/mm/abort-macro.S +++ b/arch/arm/mm/abort-macro.S @@ -13,6 +13,7 @@ tst \psr, #PSR_T_BIT beq not_thumb ldrh \tmp, [\pc] @ Read aborted Thumb instruction + uaccess_disable ip @ disable userspace access and \tmp, \tmp, # 0xfe00 @ Mask opcode field cmp \tmp, # 0x5600 @ Is it ldrsb? orreq \tmp, \tmp, #1 << 11 @ Set L-bit if yes @@ -29,12 +30,9 @@ not_thumb: * [7:4] == 1101 * [20] == 0 */ - .macro do_ldrd_abort, tmp, insn - tst \insn, #0x0e100000 @ [27:25,20] == 0 - bne not_ldrd - and \tmp, \insn, #0x000000f0 @ [7:4] == 1101 - cmp \tmp, #0x000000d0 - beq do_DataAbort -not_ldrd: + .macro teq_ldrd, tmp, insn + mov \tmp, #0x0e100000 + orr \tmp, #0x000000f0 + and \tmp, \insn, \tmp + teq \tmp, #0x000000d0 .endm - diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 870838a..1cb9c1c 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -291,13 +291,13 @@ static struct mem_type mem_types[] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_RDONLY, .prot_l1 = PMD_TYPE_TABLE, - .domain = DOMAIN_USER, + .domain = DOMAIN_VECTORS, }, [MT_HIGH_VECTORS] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_USER | L_PTE_RDONLY, .prot_l1 = PMD_TYPE_TABLE, - .domain = DOMAIN_USER, + .domain = DOMAIN_VECTORS, }, [MT_MEMORY_RWX] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY, diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c index a3681f1..e683db1 100644 --- a/arch/arm/mm/pgd.c +++ b/arch/arm/mm/pgd.c @@ -84,6 +84,16 @@ pgd_t *pgd_alloc(struct mm_struct *mm) if (!new_pte) goto no_pte; +#ifndef CONFIG_ARM_LPAE + /* + * Modify the PTE pointer to have the correct domain. This + * needs to be the vectors domain to avoid the low vectors + * being unmapped. + */ + pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK; + pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS); +#endif + init_pud = pud_offset(init_pgd, 0); init_pmd = pmd_offset(init_pud, 0); init_pte = pte_offset_map(init_pmd, 0); diff --git a/arch/arm/nwfpe/entry.S b/arch/arm/nwfpe/entry.S index 71df435..39c20af 100644 --- a/arch/arm/nwfpe/entry.S +++ b/arch/arm/nwfpe/entry.S @@ -95,9 +95,10 @@ emulate: reteq r4 @ no, return failure next: + uaccess_enable r3 .Lx1: ldrt r6, [r5], #4 @ get the next instruction and @ increment PC - + uaccess_disable r3 and r2, r6, #0x0F000000 @ test for FP insns teq r2, #0x0C000000 teqne r2, #0x0D000000 diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S index f00e080..10fd99c 100644 --- a/arch/arm/xen/hypercall.S +++ b/arch/arm/xen/hypercall.S @@ -98,8 +98,23 @@ ENTRY(privcmd_call) mov r1, r2 mov r2, r3 ldr r3, [sp, #8] + /* + * Privcmd calls are issued by the userspace. We need to allow the + * kernel to access the userspace memory before issuing the hypercall. + */ + uaccess_enable r4 + + /* r4 is loaded now as we use it as scratch register before */ ldr r4, [sp, #4] __HVC(XEN_IMM) + + /* + * Disable userspace access from kernel. This is fine to do it + * unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is + * called before. + */ + uaccess_disable r4 + ldm sp!, {r4} ret lr ENDPROC(privcmd_call); |