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suppressed page_unprotect_range() - fixed access_ok() 

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3641 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2007-11-14 10:51:00 +00:00
parent 9b0b82037a
commit dae3270c6e
4 changed files with 17 additions and 23 deletions
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1
cpu-all.h
View File

@ -690,7 +690,6 @@ extern unsigned long qemu_host_page_mask;
void page_dump(FILE *f); void page_dump(FILE *f);
int page_get_flags(target_ulong address); int page_get_flags(target_ulong address);
void page_set_flags(target_ulong start, target_ulong end, int flags); void page_set_flags(target_ulong start, target_ulong end, int flags);
void page_unprotect_range(target_ulong data, target_ulong data_size);
int page_check_range(target_ulong start, target_ulong len, int flags); int page_check_range(target_ulong start, target_ulong len, int flags);
CPUState *cpu_copy(CPUState *env); CPUState *cpu_copy(CPUState *env);

28
exec.c
View File

@ -1894,10 +1894,19 @@ int page_check_range(target_ulong start, target_ulong len, int flags)
if( !(p->flags & PAGE_VALID) ) if( !(p->flags & PAGE_VALID) )
return -1; return -1;
if (!(p->flags & PAGE_READ) && (flags & PAGE_READ) ) if ((flags & PAGE_READ) && !(p->flags & PAGE_READ))
return -1; return -1;
if (!(p->flags & PAGE_WRITE) && (flags & PAGE_WRITE) ) if (flags & PAGE_WRITE) {
if (!(p->flags & PAGE_WRITE_ORG))
return -1; return -1;
/* unprotect the page if it was put read-only because it
contains translated code */
if (!(p->flags & PAGE_WRITE)) {
if (!page_unprotect(addr, 0, NULL))
return -1;
}
return 0;
}
} }
return 0; return 0;
} }
@ -1942,21 +1951,6 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc)
return 0; return 0;
} }
/* call this function when system calls directly modify a memory area */
/* ??? This should be redundant now we have lock_user. */
void page_unprotect_range(target_ulong data, target_ulong data_size)
{
target_ulong start, end, addr;
start = data;
end = start + data_size;
start &= TARGET_PAGE_MASK;
end = TARGET_PAGE_ALIGN(end);
for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
page_unprotect(addr, 0, NULL);
}
}
static inline void tlb_set_dirty(CPUState *env, static inline void tlb_set_dirty(CPUState *env,
unsigned long addr, target_ulong vaddr) unsigned long addr, target_ulong vaddr)
{ {

7
linux-user/qemu.h
View File

@ -207,8 +207,11 @@ int target_msync(abi_ulong start, abi_ulong len, int flags);
#define VERIFY_READ 0 #define VERIFY_READ 0
#define VERIFY_WRITE 1 /* implies read access */ #define VERIFY_WRITE 1 /* implies read access */
#define access_ok(type,addr,size) \ static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
(page_check_range((target_ulong)addr,size,(type==VERIFY_READ)?PAGE_READ:PAGE_WRITE)==0) {
return page_check_range((target_ulong)addr, size,
(type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
}
/* NOTE __get_user and __put_user use host pointers and don't check access. */ /* NOTE __get_user and __put_user use host pointers and don't check access. */
/* These are usually used to access struct data members once the /* These are usually used to access struct data members once the

2
linux-user/syscall.c
View File

@ -2773,7 +2773,6 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
ret = 0; /* avoid warning */ ret = 0; /* avoid warning */
break; break;
case TARGET_NR_read: case TARGET_NR_read:
page_unprotect_range(arg2, arg3);
if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0))) if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
goto efault; goto efault;
ret = get_errno(read(arg1, p, arg3)); ret = get_errno(read(arg1, p, arg3));
@ -4537,7 +4536,6 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
break; break;
#ifdef TARGET_NR_pread #ifdef TARGET_NR_pread
case TARGET_NR_pread: case TARGET_NR_pread:
page_unprotect_range(arg2, arg3);
if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0))) if (!(p = lock_user(VERIFY_WRITE, arg2, arg3, 0)))
goto efault; goto efault;
ret = get_errno(pread(arg1, p, arg3, arg4)); ret = get_errno(pread(arg1, p, arg3, arg4));