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>

4 files changed, 19 insertions, 18 deletions

diff --git a/bsd-user/elfload.c b/bsd-user/elfload.c
index 32378af..5f4d824 100644
--- a/bsd-user/elfload.c
+++ b/bsd-user/elfload.c
@@ -737,7 +737,7 @@ static void padzero(abi_ulong elf_bss, abi_ulong last_bss)
             end_addr1 = REAL_HOST_PAGE_ALIGN(elf_bss);
             end_addr = HOST_PAGE_ALIGN(elf_bss);
             if (end_addr1 < end_addr) {
-                mmap((void *)g2h(end_addr1), end_addr - end_addr1,
+                mmap((void *)g2h_untagged(end_addr1), end_addr - end_addr1,
                      PROT_READ|PROT_WRITE|PROT_EXEC,
                      MAP_FIXED|MAP_PRIVATE|MAP_ANON, -1, 0);
             }
diff --git a/bsd-user/main.c b/bsd-user/main.c
index 385d358..798aba5 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -1055,7 +1055,7 @@ int main(int argc, char **argv)
     env->idt.base = target_mmap(0, sizeof(uint64_t) * (env->idt.limit + 1),
                                 PROT_READ|PROT_WRITE,
                                 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
-    idt_table = g2h(env->idt.base);
+    idt_table = g2h_untagged(env->idt.base);
     set_idt(0, 0);
     set_idt(1, 0);
     set_idt(2, 0);
@@ -1085,7 +1085,7 @@ int main(int argc, char **argv)
                                     PROT_READ|PROT_WRITE,
                                     MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
         env->gdt.limit = sizeof(uint64_t) * TARGET_GDT_ENTRIES - 1;
-        gdt_table = g2h(env->gdt.base);
+        gdt_table = g2h_untagged(env->gdt.base);
 #ifdef TARGET_ABI32
         write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
                  DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index 17f4cd8..01ec808 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -102,7 +102,8 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
             }
             end = host_end;
         }
-        ret = mprotect(g2h(host_start), qemu_host_page_size, prot1 & PAGE_BITS);
+        ret = mprotect(g2h_untagged(host_start),
+                       qemu_host_page_size, prot1 & PAGE_BITS);
         if (ret != 0)
             goto error;
         host_start += qemu_host_page_size;
@@ -112,8 +113,8 @@ int target_mprotect(abi_ulong start, abi_ulong len, int 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), qemu_host_page_size,
-                       prot1 & PAGE_BITS);
+        ret = mprotect(g2h_untagged(host_end - qemu_host_page_size),
+                       qemu_host_page_size, prot1 & PAGE_BITS);
         if (ret != 0)
             goto error;
         host_end -= qemu_host_page_size;
@@ -121,7 +122,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
 
     /* handle the pages in the middle */
     if (host_start < host_end) {
-        ret = mprotect(g2h(host_start), host_end - host_start, prot);
+        ret = mprotect(g2h_untagged(host_start), host_end - host_start, prot);
         if (ret != 0)
             goto error;
     }
@@ -143,7 +144,7 @@ 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;
@@ -175,7 +176,7 @@ static int mmap_frag(abi_ulong real_start,
             mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE);
 
         /* read the corresponding file data */
-        pread(fd, g2h(start), end - start, offset);
+        pread(fd, g2h_untagged(start), end - start, offset);
 
         /* put final protection */
         if (prot_new != (prot1 | PROT_WRITE))
@@ -300,7 +301,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int 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(mmap_start),
+        p = mmap(g2h_untagged(mmap_start),
                  host_len, prot, flags | MAP_FIXED, fd, host_offset);
         if (p == MAP_FAILED)
             goto fail;
@@ -344,7 +345,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
                                   -1, 0);
             if (retaddr == -1)
                 goto fail;
-            pread(fd, g2h(start), len, offset);
+            pread(fd, g2h_untagged(start), len, offset);
             if (!(prot & PROT_WRITE)) {
                 ret = target_mprotect(start, len, prot);
                 if (ret != 0) {
@@ -390,7 +391,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int 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,
                      prot, flags, fd, offset1);
             if (p == MAP_FAILED)
                 goto fail;
@@ -456,7 +457,7 @@ int target_munmap(abi_ulong start, abi_ulong len)
     ret = 0;
     /* unmap what we can */
     if (real_start < real_end) {
-        ret = munmap(g2h(real_start), real_end - real_start);
+        ret = munmap(g2h_untagged(real_start), real_end - real_start);
     }
 
     if (ret == 0)
@@ -479,5 +480,5 @@ int target_msync(abi_ulong start, abi_ulong len, int flags)
         return 0;
 
     start &= qemu_host_page_mask;
-    return msync(g2h(start), end - start, flags);
+    return msync(g2h_untagged(start), end - start, flags);
 }
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index 4076ada..d2bcaab 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -356,13 +356,13 @@ static inline void *lock_user(int type, abi_ulong guest_addr, long len, int copy
         void *addr;
         addr = g_malloc(len);
         if (copy)
-            memcpy(addr, g2h(guest_addr), len);
+            memcpy(addr, g2h_untagged(guest_addr), len);
         else
             memset(addr, 0, len);
         return addr;
     }
 #else
-    return g2h(guest_addr);
+    return g2h_untagged(guest_addr);
 #endif
 }
 
@@ -376,10 +376,10 @@ static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
 #ifdef DEBUG_REMAP
     if (!host_ptr)
         return;
-    if (host_ptr == g2h(guest_addr))
+    if (host_ptr == g2h_untagged(guest_addr))
         return;
     if (len > 0)
-        memcpy(g2h(guest_addr), host_ptr, len);
+        memcpy(g2h_untagged(guest_addr), host_ptr, len);
     g_free(host_ptr);
 #endif
 }