From 671028728083e856e9919221b109e3b2cd2ccc49 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Thu, 9 Sep 2021 12:47:00 +0200 Subject: [PATCH] parisc: Implement __get/put_kernel_nofault() Remove CONFIG_SET_FS from parisc, so we need to add __get_kernel_nofault() and __put_kernel_nofault(), define HAVE_GET_KERNEL_NOFAULT and remove set_fs(), get_fs(), load_sr2(), thread_info->addr_limit, KERNEL_DS and USER_DS. The nice side-effect of this patch is that we now can directly access userspace via sr3 without the need to use a temporary sr2 which is either copied from sr3 or set to zero (for kernel space). Signed-off-by: Helge Deller Suggested-by: Arnd Bergmann --- arch/parisc/Kconfig | 1 - arch/parisc/include/asm/processor.h | 4 - arch/parisc/include/asm/thread_info.h | 2 - arch/parisc/include/asm/uaccess.h | 122 +++++++++++++------------- arch/parisc/kernel/asm-offsets.c | 1 - arch/parisc/lib/lusercopy.S | 18 +--- 6 files changed, 62 insertions(+), 86 deletions(-) diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 86e879608e2a..4742b6f169b7 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -64,7 +64,6 @@ config PARISC select HAVE_KPROBES_ON_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_SOFTIRQ_ON_OWN_STACK if IRQSTACKS - select SET_FS select TRACE_IRQFLAGS_SUPPORT help diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index b5fbcd2c1780..eeb7da064289 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -101,10 +101,6 @@ DECLARE_PER_CPU(struct cpuinfo_parisc, cpu_data); #define CPU_HVERSION ((boot_cpu_data.hversion >> 4) & 0x0FFF) -typedef struct { - int seg; -} mm_segment_t; - #define ARCH_MIN_TASKALIGN 8 struct thread_struct { diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h index 0bd38a972cea..00ad50fef769 100644 --- a/arch/parisc/include/asm/thread_info.h +++ b/arch/parisc/include/asm/thread_info.h @@ -11,7 +11,6 @@ struct thread_info { struct task_struct *task; /* main task structure */ unsigned long flags; /* thread_info flags (see TIF_*) */ - mm_segment_t addr_limit; /* user-level address space limit */ __u32 cpu; /* current CPU */ int preempt_count; /* 0=premptable, <0=BUG; will also serve as bh-counter */ }; @@ -21,7 +20,6 @@ struct thread_info { .task = &tsk, \ .flags = 0, \ .cpu = 0, \ - .addr_limit = KERNEL_DS, \ .preempt_count = INIT_PREEMPT_COUNT, \ } diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h index cfb4ca7e39fe..192ad9e11b25 100644 --- a/arch/parisc/include/asm/uaccess.h +++ b/arch/parisc/include/asm/uaccess.h @@ -11,14 +11,6 @@ #include #include -#define KERNEL_DS ((mm_segment_t){0}) -#define USER_DS ((mm_segment_t){1}) - -#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) - -#define get_fs() (current_thread_info()->addr_limit) -#define set_fs(x) (current_thread_info()->addr_limit = (x)) - /* * Note that since kernel addresses are in a separate address space on * parisc, we don't need to do anything for access_ok(). @@ -33,11 +25,11 @@ #define get_user __get_user #if !defined(CONFIG_64BIT) -#define LDD_USER(val, ptr) __get_user_asm64(val, ptr) -#define STD_USER(x, ptr) __put_user_asm64(x, ptr) +#define LDD_USER(sr, val, ptr) __get_user_asm64(sr, val, ptr) +#define STD_USER(sr, x, ptr) __put_user_asm64(sr, x, ptr) #else -#define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr) -#define STD_USER(x, ptr) __put_user_asm("std", x, ptr) +#define LDD_USER(sr, val, ptr) __get_user_asm(sr, val, "ldd", ptr) +#define STD_USER(sr, x, ptr) __put_user_asm(sr, "std", x, ptr) #endif /* @@ -67,28 +59,15 @@ struct exception_table_entry { #define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\ ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1) -/* - * load_sr2() preloads the space register %%sr2 - based on the value of - * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which - * is 0), or with the current value of %%sr3 to access user space (USER_DS) - * memory. The following __get_user_asm() and __put_user_asm() functions have - * %%sr2 hard-coded to access the requested memory. - */ -#define load_sr2() \ - __asm__(" or,= %0,%%r0,%%r0\n\t" \ - " mfsp %%sr3,%0\n\t" \ - " mtsp %0,%%sr2\n\t" \ - : : "r"(get_fs()) : ) - -#define __get_user_internal(val, ptr) \ +#define __get_user_internal(sr, val, ptr) \ ({ \ register long __gu_err __asm__ ("r8") = 0; \ \ switch (sizeof(*(ptr))) { \ - case 1: __get_user_asm(val, "ldb", ptr); break; \ - case 2: __get_user_asm(val, "ldh", ptr); break; \ - case 4: __get_user_asm(val, "ldw", ptr); break; \ - case 8: LDD_USER(val, ptr); break; \ + case 1: __get_user_asm(sr, val, "ldb", ptr); break; \ + case 2: __get_user_asm(sr, val, "ldh", ptr); break; \ + case 4: __get_user_asm(sr, val, "ldw", ptr); break; \ + case 8: LDD_USER(sr, val, ptr); break; \ default: BUILD_BUG(); \ } \ \ @@ -97,15 +76,14 @@ struct exception_table_entry { #define __get_user(val, ptr) \ ({ \ - load_sr2(); \ - __get_user_internal(val, ptr); \ + __get_user_internal("%%sr3,", val, ptr); \ }) -#define __get_user_asm(val, ldx, ptr) \ +#define __get_user_asm(sr, val, ldx, ptr) \ { \ register long __gu_val; \ \ - __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \ + __asm__("1: " ldx " 0(" sr "%2),%0\n" \ "9:\n" \ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ : "=r"(__gu_val), "=r"(__gu_err) \ @@ -114,9 +92,22 @@ struct exception_table_entry { (val) = (__force __typeof__(*(ptr))) __gu_val; \ } +#define HAVE_GET_KERNEL_NOFAULT +#define __get_kernel_nofault(dst, src, type, err_label) \ +{ \ + type __z; \ + long __err; \ + __err = __get_user_internal("%%sr0,", __z, (type *)(src)); \ + if (unlikely(__err)) \ + goto err_label; \ + else \ + *(type *)(dst) = __z; \ +} + + #if !defined(CONFIG_64BIT) -#define __get_user_asm64(val, ptr) \ +#define __get_user_asm64(sr, val, ptr) \ { \ union { \ unsigned long long l; \ @@ -124,8 +115,8 @@ struct exception_table_entry { } __gu_tmp; \ \ __asm__(" copy %%r0,%R0\n" \ - "1: ldw 0(%%sr2,%2),%0\n" \ - "2: ldw 4(%%sr2,%2),%R0\n" \ + "1: ldw 0(" sr "%2),%0\n" \ + "2: ldw 4(" sr "%2),%R0\n" \ "9:\n" \ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ @@ -138,16 +129,16 @@ struct exception_table_entry { #endif /* !defined(CONFIG_64BIT) */ -#define __put_user_internal(x, ptr) \ +#define __put_user_internal(sr, x, ptr) \ ({ \ register long __pu_err __asm__ ("r8") = 0; \ __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ \ switch (sizeof(*(ptr))) { \ - case 1: __put_user_asm("stb", __x, ptr); break; \ - case 2: __put_user_asm("sth", __x, ptr); break; \ - case 4: __put_user_asm("stw", __x, ptr); break; \ - case 8: STD_USER(__x, ptr); break; \ + case 1: __put_user_asm(sr, "stb", __x, ptr); break; \ + case 2: __put_user_asm(sr, "sth", __x, ptr); break; \ + case 4: __put_user_asm(sr, "stw", __x, ptr); break; \ + case 8: STD_USER(sr, __x, ptr); break; \ default: BUILD_BUG(); \ } \ \ @@ -156,10 +147,20 @@ struct exception_table_entry { #define __put_user(x, ptr) \ ({ \ - load_sr2(); \ - __put_user_internal(x, ptr); \ + __put_user_internal("%%sr3,", x, ptr); \ }) +#define __put_kernel_nofault(dst, src, type, err_label) \ +{ \ + type __z = *(type *)(src); \ + long __err; \ + __err = __put_user_internal("%%sr0,", __z, (type *)(dst)); \ + if (unlikely(__err)) \ + goto err_label; \ +} + + + /* * The "__put_user/kernel_asm()" macros tell gcc they read from memory @@ -170,26 +171,26 @@ struct exception_table_entry { * r8 is already listed as err. */ -#define __put_user_asm(stx, x, ptr) \ - __asm__ __volatile__ ( \ - "1: " stx " %2,0(%%sr2,%1)\n" \ - "9:\n" \ - ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ - : "=r"(__pu_err) \ +#define __put_user_asm(sr, stx, x, ptr) \ + __asm__ __volatile__ ( \ + "1: " stx " %2,0(" sr "%1)\n" \ + "9:\n" \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ + : "=r"(__pu_err) \ : "r"(ptr), "r"(x), "0"(__pu_err)) #if !defined(CONFIG_64BIT) -#define __put_user_asm64(__val, ptr) do { \ - __asm__ __volatile__ ( \ - "1: stw %2,0(%%sr2,%1)\n" \ - "2: stw %R2,4(%%sr2,%1)\n" \ - "9:\n" \ - ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ - ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ - : "=r"(__pu_err) \ - : "r"(ptr), "r"(__val), "0"(__pu_err)); \ +#define __put_user_asm64(sr, __val, ptr) do { \ + __asm__ __volatile__ ( \ + "1: stw %2,0(" sr "%1)\n" \ + "2: stw %R2,4(" sr "%1)\n" \ + "9:\n" \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ + : "=r"(__pu_err) \ + : "r"(ptr), "r"(__val), "0"(__pu_err)); \ } while (0) #endif /* !defined(CONFIG_64BIT) */ @@ -200,12 +201,11 @@ struct exception_table_entry { */ extern long strncpy_from_user(char *, const char __user *, long); -extern unsigned lclear_user(void __user *, unsigned long); +extern __must_check unsigned lclear_user(void __user *, unsigned long); extern __must_check long strnlen_user(const char __user *src, long n); /* * Complex access routines -- macros */ -#define user_addr_max() (~0UL) #define clear_user lclear_user #define __clear_user lclear_user diff --git a/arch/parisc/kernel/asm-offsets.c b/arch/parisc/kernel/asm-offsets.c index 33113ba24054..22924a3f1728 100644 --- a/arch/parisc/kernel/asm-offsets.c +++ b/arch/parisc/kernel/asm-offsets.c @@ -230,7 +230,6 @@ int main(void) DEFINE(TI_TASK, offsetof(struct thread_info, task)); DEFINE(TI_FLAGS, offsetof(struct thread_info, flags)); DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); - DEFINE(TI_SEGMENT, offsetof(struct thread_info, addr_limit)); DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count)); DEFINE(THREAD_SZ, sizeof(struct thread_info)); /* THREAD_SZ_ALGN includes space for a stack frame. */ diff --git a/arch/parisc/lib/lusercopy.S b/arch/parisc/lib/lusercopy.S index 0aad5ce89f4d..b428d29e45fb 100644 --- a/arch/parisc/lib/lusercopy.S +++ b/arch/parisc/lib/lusercopy.S @@ -27,21 +27,6 @@ #include #include - /* - * get_sr gets the appropriate space value into - * sr1 for kernel/user space access, depending - * on the flag stored in the task structure. - */ - - .macro get_sr - mfctl %cr30,%r1 - ldw TI_SEGMENT(%r1),%r22 - mfsp %sr3,%r1 - or,<> %r22,%r0,%r0 - copy %r0,%r1 - mtsp %r1,%sr1 - .endm - /* * unsigned long lclear_user(void *to, unsigned long n) * @@ -51,10 +36,9 @@ ENTRY_CFI(lclear_user) comib,=,n 0,%r25,$lclu_done - get_sr $lclu_loop: addib,<> -1,%r25,$lclu_loop -1: stbs,ma %r0,1(%sr1,%r26) +1: stbs,ma %r0,1(%sr3,%r26) $lclu_done: bv %r0(%r2) -- 2.20.1