exec: Use cpu_untagged_addr in g2h; split out g2h_untagged

Use g2h_untagged in contexts that have no cpu, e.g. the binary
loaders that operate before the primary cpu is created.  As a
colollary, target_mmap and friends must use untagged addresses,
since they are used by the loaders.

Use g2h_untagged on values returned from target_mmap, as the
kernel never applies a tag itself.

Use g2h_untagged on all pc values.  The only current user of
tags, aarch64, removes tags from code addresses upon branch,
so "pc" is always untagged.

Use g2h with the cpu context on hand wherever possible.

Use g2h_untagged in lock_user, which will be updated soon.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 38 insertions, 34 deletions

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 0c2d660bc4..e7fd99f1ac 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -912,7 +912,7 @@ abi_long do_brk(abi_ulong new_brk)
         /* Heap contents are initialized to zero, as for anonymous
          * mapped pages.  */
         if (new_brk > target_brk) {
-            memset(g2h(target_brk), 0, new_brk - target_brk);
+            memset(g2h_untagged(target_brk), 0, new_brk - target_brk);
         }
 	target_brk = new_brk;
         DEBUGF_BRK(TARGET_ABI_FMT_lx " (new_brk <= brk_page)\n", target_brk);
@@ -938,7 +938,7 @@ abi_long do_brk(abi_ulong new_brk)
          * come from the remaining part of the previous page: it may
          * contains garbage data due to a previous heap usage (grown
          * then shrunken).  */
-        memset(g2h(target_brk), 0, brk_page - target_brk);
+        memset(g2h_untagged(target_brk), 0, brk_page - target_brk);
 
         target_brk = new_brk;
         brk_page = HOST_PAGE_ALIGN(target_brk);
@@ -4622,7 +4622,7 @@ static inline abi_ulong do_shmat(CPUArchState *cpu_env,
     mmap_lock();
 
     if (shmaddr)
-        host_raddr = shmat(shmid, (void *)g2h(shmaddr), shmflg);
+        host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
     else {
         abi_ulong mmap_start;
 
@@ -4633,7 +4633,8 @@ static inline abi_ulong do_shmat(CPUArchState *cpu_env,
             errno = ENOMEM;
             host_raddr = (void *)-1;
         } else
-            host_raddr = shmat(shmid, g2h(mmap_start), shmflg | SHM_REMAP);
+            host_raddr = shmat(shmid, g2h_untagged(mmap_start),
+                               shmflg | SHM_REMAP);
     }
 
     if (host_raddr == (void *)-1) {
@@ -4674,7 +4675,7 @@ static inline abi_long do_shmdt(abi_ulong shmaddr)
             break;
         }
     }
-    rv = get_errno(shmdt(g2h(shmaddr)));
+    rv = get_errno(shmdt(g2h_untagged(shmaddr)));
 
     mmap_unlock();
 
@@ -6145,10 +6146,10 @@ static abi_long write_ldt(CPUX86State *env,
                                     MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
         if (env->ldt.base == -1)
             return -TARGET_ENOMEM;
-        memset(g2h(env->ldt.base), 0,
+        memset(g2h_untagged(env->ldt.base), 0,
                TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE);
         env->ldt.limit = 0xffff;
-        ldt_table = g2h(env->ldt.base);
+        ldt_table = g2h_untagged(env->ldt.base);
     }
 
     /* NOTE: same code as Linux kernel */
@@ -6216,7 +6217,7 @@ static abi_long do_modify_ldt(CPUX86State *env, int func, abi_ulong ptr,
 #if defined(TARGET_ABI32)
 abi_long do_set_thread_area(CPUX86State *env, abi_ulong ptr)
 {
-    uint64_t *gdt_table = g2h(env->gdt.base);
+    uint64_t *gdt_table = g2h_untagged(env->gdt.base);
     struct target_modify_ldt_ldt_s ldt_info;
     struct target_modify_ldt_ldt_s *target_ldt_info;
     int seg_32bit, contents, read_exec_only, limit_in_pages;
@@ -6302,7 +6303,7 @@ install:
 static abi_long do_get_thread_area(CPUX86State *env, abi_ulong ptr)
 {
     struct target_modify_ldt_ldt_s *target_ldt_info;
-    uint64_t *gdt_table = g2h(env->gdt.base);
+    uint64_t *gdt_table = g2h_untagged(env->gdt.base);
     uint32_t base_addr, limit, flags;
     int seg_32bit, contents, read_exec_only, limit_in_pages, idx;
     int seg_not_present, useable, lm;
@@ -7597,8 +7598,8 @@ static int do_safe_futex(int *uaddr, int op, int val,
    tricky.  However they're probably useless because guest atomic
    operations won't work either.  */
 #if defined(TARGET_NR_futex)
-static int do_futex(target_ulong uaddr, int op, int val, target_ulong timeout,
-                    target_ulong uaddr2, int val3)
+static int do_futex(CPUState *cpu, target_ulong uaddr, int op, int val,
+                    target_ulong timeout, target_ulong uaddr2, int val3)
 {
     struct timespec ts, *pts;
     int base_op;
@@ -7619,11 +7620,14 @@ static int do_futex(target_ulong uaddr, int op, int val, target_ulong timeout,
         } else {
             pts = NULL;
         }
-        return do_safe_futex(g2h(uaddr), op, tswap32(val), pts, NULL, val3);
+        return do_safe_futex(g2h(cpu, uaddr),
+                             op, tswap32(val), pts, NULL, val3);
     case FUTEX_WAKE:
-        return do_safe_futex(g2h(uaddr), op, val, NULL, NULL, 0);
+        return do_safe_futex(g2h(cpu, uaddr),
+                             op, val, NULL, NULL, 0);
     case FUTEX_FD:
-        return do_safe_futex(g2h(uaddr), op, val, NULL, NULL, 0);
+        return do_safe_futex(g2h(cpu, uaddr),
+                             op, val, NULL, NULL, 0);
     case FUTEX_REQUEUE:
     case FUTEX_CMP_REQUEUE:
     case FUTEX_WAKE_OP:
@@ -7633,10 +7637,9 @@ static int do_futex(target_ulong uaddr, int op, int val, target_ulong timeout,
            to satisfy the compiler.  We do not need to tswap TIMEOUT
            since it's not compared to guest memory.  */
         pts = (struct timespec *)(uintptr_t) timeout;
-        return do_safe_futex(g2h(uaddr), op, val, pts, g2h(uaddr2),
+        return do_safe_futex(g2h(cpu, uaddr), op, val, pts, g2h(cpu, uaddr2),
                              (base_op == FUTEX_CMP_REQUEUE
-                                      ? tswap32(val3)
-                                      : val3));
+                              ? tswap32(val3) : val3));
     default:
         return -TARGET_ENOSYS;
     }
@@ -7644,7 +7647,8 @@ static int do_futex(target_ulong uaddr, int op, int val, target_ulong timeout,
 #endif
 
 #if defined(TARGET_NR_futex_time64)
-static int do_futex_time64(target_ulong uaddr, int op, int val, target_ulong timeout,
+static int do_futex_time64(CPUState *cpu, target_ulong uaddr, int op,
+                           int val, target_ulong timeout,
                            target_ulong uaddr2, int val3)
 {
     struct timespec ts, *pts;
@@ -7668,11 +7672,12 @@ static int do_futex_time64(target_ulong uaddr, int op, int val, target_ulong tim
         } else {
             pts = NULL;
         }
-        return do_safe_futex(g2h(uaddr), op, tswap32(val), pts, NULL, val3);
+        return do_safe_futex(g2h(cpu, uaddr), op,
+                             tswap32(val), pts, NULL, val3);
     case FUTEX_WAKE:
-        return do_safe_futex(g2h(uaddr), op, val, NULL, NULL, 0);
+        return do_safe_futex(g2h(cpu, uaddr), op, val, NULL, NULL, 0);
     case FUTEX_FD:
-        return do_safe_futex(g2h(uaddr), op, val, NULL, NULL, 0);
+        return do_safe_futex(g2h(cpu, uaddr), op, val, NULL, NULL, 0);
     case FUTEX_REQUEUE:
     case FUTEX_CMP_REQUEUE:
     case FUTEX_WAKE_OP:
@@ -7682,10 +7687,9 @@ static int do_futex_time64(target_ulong uaddr, int op, int val, target_ulong tim
            to satisfy the compiler.  We do not need to tswap TIMEOUT
            since it's not compared to guest memory.  */
         pts = (struct timespec *)(uintptr_t) timeout;
-        return do_safe_futex(g2h(uaddr), op, val, pts, g2h(uaddr2),
+        return do_safe_futex(g2h(cpu, uaddr), op, val, pts, g2h(cpu, uaddr2),
                              (base_op == FUTEX_CMP_REQUEUE
-                                      ? tswap32(val3)
-                                      : val3));
+                              ? tswap32(val3) : val3));
     default:
         return -TARGET_ENOSYS;
     }
@@ -7860,7 +7864,7 @@ static int open_self_maps(void *cpu_env, int fd)
             const char *path;
 
             max = h2g_valid(max - 1) ?
-                max : (uintptr_t) g2h(GUEST_ADDR_MAX) + 1;
+                max : (uintptr_t) g2h_untagged(GUEST_ADDR_MAX) + 1;
 
             if (page_check_range(h2g(min), max - min, flags) == -1) {
                 continue;
@@ -8277,8 +8281,8 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
 
             if (ts->child_tidptr) {
                 put_user_u32(0, ts->child_tidptr);
-                do_sys_futex(g2h(ts->child_tidptr), FUTEX_WAKE, INT_MAX,
-                          NULL, NULL, 0);
+                do_sys_futex(g2h(cpu, ts->child_tidptr),
+                             FUTEX_WAKE, INT_MAX, NULL, NULL, 0);
             }
             thread_cpu = NULL;
             g_free(ts);
@@ -8643,7 +8647,7 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
             if (!arg5) {
                 ret = mount(p, p2, p3, (unsigned long)arg4, NULL);
             } else {
-                ret = mount(p, p2, p3, (unsigned long)arg4, g2h(arg5));
+                ret = mount(p, p2, p3, (unsigned long)arg4, g2h(cpu, arg5));
             }
             ret = get_errno(ret);
 
@@ -9738,15 +9742,15 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
         /* ??? msync/mlock/munlock are broken for softmmu.  */
 #ifdef TARGET_NR_msync
     case TARGET_NR_msync:
-        return get_errno(msync(g2h(arg1), arg2, arg3));
+        return get_errno(msync(g2h(cpu, arg1), arg2, arg3));
 #endif
 #ifdef TARGET_NR_mlock
     case TARGET_NR_mlock:
-        return get_errno(mlock(g2h(arg1), arg2));
+        return get_errno(mlock(g2h(cpu, arg1), arg2));
 #endif
 #ifdef TARGET_NR_munlock
     case TARGET_NR_munlock:
-        return get_errno(munlock(g2h(arg1), arg2));
+        return get_errno(munlock(g2h(cpu, arg1), arg2));
 #endif
 #ifdef TARGET_NR_mlockall
     case TARGET_NR_mlockall:
@@ -12237,7 +12241,7 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
 
 #if defined(TARGET_NR_set_tid_address) && defined(__NR_set_tid_address)
     case TARGET_NR_set_tid_address:
-        return get_errno(set_tid_address((int *)g2h(arg1)));
+        return get_errno(set_tid_address((int *)g2h(cpu, arg1)));
 #endif
 
     case TARGET_NR_tkill:
@@ -12324,11 +12328,11 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
 #endif
 #ifdef TARGET_NR_futex
     case TARGET_NR_futex:
-        return do_futex(arg1, arg2, arg3, arg4, arg5, arg6);
+        return do_futex(cpu, arg1, arg2, arg3, arg4, arg5, arg6);
 #endif
 #ifdef TARGET_NR_futex_time64
     case TARGET_NR_futex_time64:
-        return do_futex_time64(arg1, arg2, arg3, arg4, arg5, arg6);
+        return do_futex_time64(cpu, arg1, arg2, arg3, arg4, arg5, arg6);
 #endif
 #if defined(TARGET_NR_inotify_init) && defined(__NR_inotify_init)
     case TARGET_NR_inotify_init: