linux-user: Use cpu_untagged_addr in access_ok; split out *_untagged

Provide both tagged and untagged versions of access_ok.
In a few places use thread_cpu, as the user is several
callees removed from do_syscall1.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 24 insertions, 13 deletions

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 902be3ff11..73d750c809 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -3510,7 +3510,7 @@ static int vma_get_mapping_count(const struct mm_struct *mm)
 static abi_ulong vma_dump_size(const struct vm_area_struct *vma)
 {
     /* if we cannot even read the first page, skip it */
-    if (!access_ok(VERIFY_READ, vma->vma_start, TARGET_PAGE_SIZE))
+    if (!access_ok_untagged(VERIFY_READ, vma->vma_start, TARGET_PAGE_SIZE))
         return (0);
 
     /*
diff --git a/linux-user/hppa/cpu_loop.c b/linux-user/hppa/cpu_loop.c
index 944511bbe4..3aaaf3337c 100644
--- a/linux-user/hppa/cpu_loop.c
+++ b/linux-user/hppa/cpu_loop.c
@@ -35,7 +35,7 @@ static abi_ulong hppa_lws(CPUHPPAState *env)
         return -TARGET_ENOSYS;
 
     case 0: /* elf32 atomic 32bit cmpxchg */
-        if ((addr & 3) || !access_ok(VERIFY_WRITE, addr, 4)) {
+        if ((addr & 3) || !access_ok(cs, VERIFY_WRITE, addr, 4)) {
             return -TARGET_EFAULT;
         }
         old = tswap32(old);
@@ -50,9 +50,9 @@ static abi_ulong hppa_lws(CPUHPPAState *env)
             return -TARGET_ENOSYS;
         }
         if (((addr | old | new) & ((1 << size) - 1))
-            || !access_ok(VERIFY_WRITE, addr, 1 << size)
-            || !access_ok(VERIFY_READ, old, 1 << size)
-            || !access_ok(VERIFY_READ, new, 1 << size)) {
+            || !access_ok(cs, VERIFY_WRITE, addr, 1 << size)
+            || !access_ok(cs, VERIFY_READ, old, 1 << size)
+            || !access_ok(cs, VERIFY_READ, new, 1 << size)) {
             return -TARGET_EFAULT;
         }
         /* Note that below we use host-endian loads so that the cmpxchg
diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index 19c8a18cd3..f813e87294 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -99,7 +99,7 @@ static bool write_ok_or_segv(CPUX86State *env, abi_ptr addr, size_t len)
      * For all the vsyscalls, NULL means "don't write anything" not
      * "write it at address 0".
      */
-    if (addr == 0 || access_ok(VERIFY_WRITE, addr, len)) {
+    if (addr == 0 || access_ok(env_cpu(env), VERIFY_WRITE, addr, len)) {
         return true;
     }
 
diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c
index 97a39204cc..9320e1d472 100644
--- a/linux-user/i386/signal.c
+++ b/linux-user/i386/signal.c
@@ -513,9 +513,10 @@ restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
 
     fpstate_addr = tswapl(sc->fpstate);
     if (fpstate_addr != 0) {
-        if (!access_ok(VERIFY_READ, fpstate_addr,
-                       sizeof(struct target_fpstate)))
+        if (!access_ok(env_cpu(env), VERIFY_READ, fpstate_addr,
+                       sizeof(struct target_fpstate))) {
             goto badframe;
+        }
 #ifndef TARGET_X86_64
         cpu_x86_frstor(env, fpstate_addr, 1);
 #else
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index b3ccffbf0f..82eabb73f8 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -491,7 +491,7 @@ extern unsigned long guest_stack_size;
 #define VERIFY_READ  PAGE_READ
 #define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
 
-static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
+static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
 {
     if (size == 0
         ? !guest_addr_valid_untagged(addr)
@@ -501,6 +501,12 @@ static inline bool access_ok(int type, abi_ulong addr, abi_ulong size)
     return page_check_range((target_ulong)addr, size, type) == 0;
 }
 
+static inline bool access_ok(CPUState *cpu, int type,
+                             abi_ulong addr, abi_ulong size)
+{
+    return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
+}
+
 /* 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 struct has
    been locked - usually with lock_user_struct.  */
@@ -636,8 +642,9 @@ abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len);
    host area will have the same contents as the guest.  */
 static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
 {
-    if (!access_ok(type, guest_addr, len))
+    if (!access_ok_untagged(type, guest_addr, len)) {
         return NULL;
+    }
 #ifdef DEBUG_REMAP
     {
         void *addr;
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 53529e4004..3d0411da57 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -3526,8 +3526,9 @@ static abi_long do_accept4(int fd, abi_ulong target_addr,
         return -TARGET_EINVAL;
     }
 
-    if (!access_ok(VERIFY_WRITE, target_addr, addrlen))
+    if (!access_ok(thread_cpu, VERIFY_WRITE, target_addr, addrlen)) {
         return -TARGET_EFAULT;
+    }
 
     addr = alloca(addrlen);
 
@@ -3557,8 +3558,9 @@ static abi_long do_getpeername(int fd, abi_ulong target_addr,
         return -TARGET_EINVAL;
     }
 
-    if (!access_ok(VERIFY_WRITE, target_addr, addrlen))
+    if (!access_ok(thread_cpu, VERIFY_WRITE, target_addr, addrlen)) {
         return -TARGET_EFAULT;
+    }
 
     addr = alloca(addrlen);
 
@@ -3588,8 +3590,9 @@ static abi_long do_getsockname(int fd, abi_ulong target_addr,
         return -TARGET_EINVAL;
     }
 
-    if (!access_ok(VERIFY_WRITE, target_addr, addrlen))
+    if (!access_ok(thread_cpu, VERIFY_WRITE, target_addr, addrlen)) {
         return -TARGET_EFAULT;
+    }
 
     addr = alloca(addrlen);