From 53a5960aadd542dd27b8705ac30df154557d5ffc Mon Sep 17 00:00:00 2001 From: pbrook Date: Sat, 25 Mar 2006 19:31:22 +0000 Subject: Avoid accessing guest memory directly in usermode emulation. git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1790 c046a42c-6fe2-441c-8c8c-71466251a162 --- linux-user/qemu.h | 141 ++++++++++++++++++++++++++++++++---------------------- 1 file changed, 84 insertions(+), 57 deletions(-) (limited to 'linux-user/qemu.h') diff --git a/linux-user/qemu.h b/linux-user/qemu.h index f385a1c92b..a797c512bb 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -69,7 +69,7 @@ typedef struct TaskState { int swi_errno; #endif #ifdef TARGET_I386 - struct target_vm86plus_struct *target_v86; + target_ulong target_v86; struct vm86_saved_state vm86_saved_regs; struct target_vm86plus_struct vm86plus; uint32_t v86flags; @@ -84,8 +84,8 @@ extern TaskState *first_task_state; int elf_exec(const char * filename, char ** argv, char ** envp, struct target_pt_regs * regs, struct image_info *infop); -void target_set_brk(char *new_brk); -long do_brk(char *new_brk); +void target_set_brk(target_ulong new_brk); +long do_brk(target_ulong new_brk); void syscall_init(void); long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3, long arg4, long arg5, long arg6); @@ -112,19 +112,18 @@ long do_rt_sigreturn(CPUState *env); void save_v86_state(CPUX86State *env); void handle_vm86_trap(CPUX86State *env, int trapno); void handle_vm86_fault(CPUX86State *env); -int do_vm86(CPUX86State *env, long subfunction, - struct target_vm86plus_struct * target_v86); +int do_vm86(CPUX86State *env, long subfunction, target_ulong v86_addr); #endif /* mmap.c */ -int target_mprotect(unsigned long start, unsigned long len, int prot); -long target_mmap(unsigned long start, unsigned long len, int prot, - int flags, int fd, unsigned long offset); -int target_munmap(unsigned long start, unsigned long len); -long target_mremap(unsigned long old_addr, unsigned long old_size, - unsigned long new_size, unsigned long flags, - unsigned long new_addr); -int target_msync(unsigned long start, unsigned long len, int flags); +int target_mprotect(target_ulong start, target_ulong len, int prot); +long target_mmap(target_ulong start, target_ulong len, int prot, + int flags, int fd, target_ulong offset); +int target_munmap(target_ulong start, target_ulong len); +long target_mremap(target_ulong old_addr, target_ulong old_size, + target_ulong new_size, unsigned long flags, + target_ulong new_addr); +int target_msync(target_ulong start, target_ulong len, int flags); /* user access */ @@ -133,21 +132,22 @@ int target_msync(unsigned long start, unsigned long len, int flags); #define access_ok(type,addr,size) (1) +/* NOTE get_user and put_user use host addresses. */ #define __put_user(x,ptr)\ ({\ int size = sizeof(*ptr);\ switch(size) {\ case 1:\ - stb(ptr, (typeof(*ptr))(x));\ + *(uint8_t *)(ptr) = (typeof(*ptr))(x);\ break;\ case 2:\ - stw(ptr, (typeof(*ptr))(x));\ + *(uint16_t *)(ptr) = tswap16((typeof(*ptr))(x));\ break;\ case 4:\ - stl(ptr, (typeof(*ptr))(x));\ + *(uint32_t *)(ptr) = tswap32((typeof(*ptr))(x));\ break;\ case 8:\ - stq(ptr, (typeof(*ptr))(x));\ + *(uint64_t *)(ptr) = tswap64((typeof(*ptr))(x));\ break;\ default:\ abort();\ @@ -160,16 +160,16 @@ int target_msync(unsigned long start, unsigned long len, int flags); int size = sizeof(*ptr);\ switch(size) {\ case 1:\ - x = (typeof(*ptr))ldub((void *)ptr);\ + x = (typeof(*ptr))*(uint8_t *)(ptr);\ break;\ case 2:\ - x = (typeof(*ptr))lduw((void *)ptr);\ + x = (typeof(*ptr))tswap16(*(uint16_t *)(ptr));\ break;\ case 4:\ - x = (typeof(*ptr))ldl((void *)ptr);\ + x = (typeof(*ptr))tswap32(*(uint32_t *)(ptr));\ break;\ case 8:\ - x = (typeof(*ptr))ldq((void *)ptr);\ + x = (typeof(*ptr))tswap64(*(uint64_t *)(ptr));\ break;\ default:\ abort();\ @@ -177,26 +177,6 @@ int target_msync(unsigned long start, unsigned long len, int flags); 0;\ }) -static inline unsigned long __copy_to_user(void *dst, const void *src, - unsigned long size) -{ - memcpy(dst, src, size); - return 0; -} - -static inline unsigned long __copy_from_user(void *dst, const void *src, - unsigned long size) -{ - memcpy(dst, src, size); - return 0; -} - -static inline unsigned long __clear_user(void *dst, unsigned long size) -{ - memset(dst, 0, size); - return 0; -} - #define put_user(x,ptr)\ ({\ int __ret;\ @@ -217,30 +197,77 @@ static inline unsigned long __clear_user(void *dst, unsigned long size) __ret;\ }) -static inline unsigned long copy_to_user(void *dst, const void *src, - unsigned long size) +/* Functions for accessing guest memory. The tget and tput functions + read/write single values, byteswapping as neccessary. The lock_user + gets a pointer to a contiguous area of guest memory, but does not perform + and byteswapping. lock_user may return either a pointer to the guest + memory, or a temporary buffer. */ + +/* Lock an area of guest memory into the host. If copy is true then the + host area will have the same contents as the guest. */ +static inline void *lock_user(target_ulong guest_addr, long len, int copy) { - if (access_ok(VERIFY_WRITE, dst, size)) - return __copy_to_user(dst, src, size); +#ifdef DEBUG_REMAP + void *addr; + addr = malloc(len); + if (copy) + memcpy(addr, g2h(guest_addr), len); else - return size; + memset(addr, 0, len); + return addr; +#else + return g2h(guest_addr); +#endif } -static inline unsigned long copy_from_user(void *dst, const void *src, - unsigned long size) +/* Unlock an area of guest memory. The first LEN bytes must be flushed back + to guest memory. */ +static inline void unlock_user(void *host_addr, target_ulong guest_addr, + long len) { - if (access_ok(VERIFY_READ, src, size)) - return __copy_from_user(dst, src, size); - else - return size; +#ifdef DEBUG_REMAP + if (host_addr == g2h(guest_addr)) + return; + if (len > 0) + memcpy(g2h(guest_addr), host_addr, len); + free(host_addr); +#endif } -static inline unsigned long clear_user(void *dst, unsigned long size) +/* Return the length of a string in target memory. */ +static inline int target_strlen(target_ulong ptr) { - if (access_ok(VERIFY_WRITE, dst, size)) - return __clear_user(dst, size); - else - return size; + return strlen(g2h(ptr)); +} + +/* Like lock_user but for null terminated strings. */ +static inline void *lock_user_string(target_ulong guest_addr) +{ + long len; + len = target_strlen(guest_addr) + 1; + return lock_user(guest_addr, len, 1); } +/* Helper macros for locking/ulocking a target struct. */ +#define lock_user_struct(host_ptr, guest_addr, copy) \ + host_ptr = lock_user(guest_addr, sizeof(*host_ptr), copy) +#define unlock_user_struct(host_ptr, guest_addr, copy) \ + unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0) + +#define tget8(addr) ldub(addr) +#define tput8(addr, val) stb(addr, val) +#define tget16(addr) lduw(addr) +#define tput16(addr, val) stw(addr, val) +#define tget32(addr) ldl(addr) +#define tput32(addr, val) stl(addr, val) +#define tget64(addr) ldq(addr) +#define tput64(addr, val) stq(addr, val) +#if TARGET_LONG_BITS == 64 +#define tgetl(addr) ldq(addr) +#define tputl(addr, val) stq(addr, val) +#else +#define tgetl(addr) ldl(addr) +#define tputl(addr, val) stl(addr, val) +#endif + #endif /* QEMU_H */ -- cgit v1.2.1