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, 24 insertions, 21 deletions

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index c52b60482e..6decfec68a 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -141,7 +141,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
             }
             end = host_end;
         }
-        ret = mprotect(g2h(host_start), qemu_host_page_size,
+        ret = mprotect(g2h_untagged(host_start), qemu_host_page_size,
                        prot1 & PAGE_BITS);
         if (ret != 0) {
             goto error;
@@ -153,7 +153,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
         for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
             prot1 |= page_get_flags(addr);
         }
-        ret = mprotect(g2h(host_end - qemu_host_page_size),
+        ret = mprotect(g2h_untagged(host_end - qemu_host_page_size),
                        qemu_host_page_size, prot1 & PAGE_BITS);
         if (ret != 0) {
             goto error;
@@ -163,7 +163,8 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
 
     /* handle the pages in the middle */
     if (host_start < host_end) {
-        ret = mprotect(g2h(host_start), host_end - host_start, host_prot);
+        ret = mprotect(g2h_untagged(host_start),
+                       host_end - host_start, host_prot);
         if (ret != 0) {
             goto error;
         }
@@ -186,7 +187,7 @@ static int mmap_frag(abi_ulong real_start,
     int prot1, prot_new;
 
     real_end = real_start + qemu_host_page_size;
-    host_start = g2h(real_start);
+    host_start = g2h_untagged(real_start);
 
     /* get the protection of the target pages outside the mapping */
     prot1 = 0;
@@ -218,7 +219,7 @@ static int mmap_frag(abi_ulong real_start,
             mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE);
 
         /* read the corresponding file data */
-        if (pread(fd, g2h(start), end - start, offset) == -1)
+        if (pread(fd, g2h_untagged(start), end - start, offset) == -1)
             return -1;
 
         /* put final protection */
@@ -229,7 +230,7 @@ static int mmap_frag(abi_ulong real_start,
             mprotect(host_start, qemu_host_page_size, prot_new);
         }
         if (prot_new & PROT_WRITE) {
-            memset(g2h(start), 0, end - start);
+            memset(g2h_untagged(start), 0, end - start);
         }
     }
     return 0;
@@ -338,7 +339,7 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align)
          *  - mremap() with MREMAP_FIXED flag
          *  - shmat() with SHM_REMAP flag
          */
-        ptr = mmap(g2h(addr), size, PROT_NONE,
+        ptr = mmap(g2h_untagged(addr), size, PROT_NONE,
                    MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);
 
         /* ENOMEM, if host address space has no memory */
@@ -497,7 +498,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
         /* Note: we prefer to control the mapping address. It is
            especially important if qemu_host_page_size >
            qemu_real_host_page_size */
-        p = mmap(g2h(start), host_len, host_prot,
+        p = mmap(g2h_untagged(start), host_len, host_prot,
                  flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
         if (p == MAP_FAILED) {
             goto fail;
@@ -505,10 +506,10 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
         /* update start so that it points to the file position at 'offset' */
         host_start = (unsigned long)p;
         if (!(flags & MAP_ANONYMOUS)) {
-            p = mmap(g2h(start), len, host_prot,
+            p = mmap(g2h_untagged(start), len, host_prot,
                      flags | MAP_FIXED, fd, host_offset);
             if (p == MAP_FAILED) {
-                munmap(g2h(start), host_len);
+                munmap(g2h_untagged(start), host_len);
                 goto fail;
             }
             host_start += offset - host_offset;
@@ -548,7 +549,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
                                   -1, 0);
             if (retaddr == -1)
                 goto fail;
-            if (pread(fd, g2h(start), len, offset) == -1)
+            if (pread(fd, g2h_untagged(start), len, offset) == -1)
                 goto fail;
             if (!(host_prot & PROT_WRITE)) {
                 ret = target_mprotect(start, len, target_prot);
@@ -592,7 +593,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
                 offset1 = 0;
             else
                 offset1 = offset + real_start - start;
-            p = mmap(g2h(real_start), real_end - real_start,
+            p = mmap(g2h_untagged(real_start), real_end - real_start,
                      host_prot, flags, fd, offset1);
             if (p == MAP_FAILED)
                 goto fail;
@@ -652,7 +653,7 @@ static void mmap_reserve(abi_ulong start, abi_ulong size)
             real_end -= qemu_host_page_size;
     }
     if (real_start != real_end) {
-        mmap(g2h(real_start), real_end - real_start, PROT_NONE,
+        mmap(g2h_untagged(real_start), real_end - real_start, PROT_NONE,
                  MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE,
                  -1, 0);
     }
@@ -707,7 +708,7 @@ int target_munmap(abi_ulong start, abi_ulong len)
         if (reserved_va) {
             mmap_reserve(real_start, real_end - real_start);
         } else {
-            ret = munmap(g2h(real_start), real_end - real_start);
+            ret = munmap(g2h_untagged(real_start), real_end - real_start);
         }
     }
 
@@ -738,8 +739,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
     mmap_lock();
 
     if (flags & MREMAP_FIXED) {
-        host_addr = mremap(g2h(old_addr), old_size, new_size,
-                           flags, g2h(new_addr));
+        host_addr = mremap(g2h_untagged(old_addr), old_size, new_size,
+                           flags, g2h_untagged(new_addr));
 
         if (reserved_va && host_addr != MAP_FAILED) {
             /* If new and old addresses overlap then the above mremap will
@@ -755,8 +756,9 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
             errno = ENOMEM;
             host_addr = MAP_FAILED;
         } else {
-            host_addr = mremap(g2h(old_addr), old_size, new_size,
-                               flags | MREMAP_FIXED, g2h(mmap_start));
+            host_addr = mremap(g2h_untagged(old_addr), old_size, new_size,
+                               flags | MREMAP_FIXED,
+                               g2h_untagged(mmap_start));
             if (reserved_va) {
                 mmap_reserve(old_addr, old_size);
             }
@@ -772,14 +774,15 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
             }
         }
         if (prot == 0) {
-            host_addr = mremap(g2h(old_addr), old_size, new_size, flags);
+            host_addr = mremap(g2h_untagged(old_addr),
+                               old_size, new_size, flags);
 
             if (host_addr != MAP_FAILED) {
                 /* Check if address fits target address space */
                 if (!guest_range_valid(h2g(host_addr), new_size)) {
                     /* Revert mremap() changes */
-                    host_addr = mremap(g2h(old_addr), new_size, old_size,
-                                       flags);
+                    host_addr = mremap(g2h_untagged(old_addr),
+                                       new_size, old_size, flags);
                     errno = ENOMEM;
                     host_addr = MAP_FAILED;
                 } else if (reserved_va && old_size > new_size) {