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, 6 insertions, 6 deletions

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 7ec9249..902be3f 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -389,7 +389,7 @@ enum {
 
 static bool init_guest_commpage(void)
 {
-    void *want = g2h(ARM_COMMPAGE & -qemu_host_page_size);
+    void *want = g2h_untagged(ARM_COMMPAGE & -qemu_host_page_size);
     void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
                       MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
 
@@ -402,7 +402,7 @@ static bool init_guest_commpage(void)
     }
 
     /* Set kernel helper versions; rest of page is 0.  */
-    __put_user(5, (uint32_t *)g2h(0xffff0ffcu));
+    __put_user(5, (uint32_t *)g2h_untagged(0xffff0ffcu));
 
     if (mprotect(addr, qemu_host_page_size, PROT_READ)) {
         perror("Protecting guest commpage");
@@ -1872,8 +1872,8 @@ static void zero_bss(abi_ulong elf_bss, abi_ulong last_bss, int prot)
        here is still actually needed.  For now, continue with it,
        but merge it with the "normal" mmap that would allocate the bss.  */
 
-    host_start = (uintptr_t) g2h(elf_bss);
-    host_end = (uintptr_t) g2h(last_bss);
+    host_start = (uintptr_t) g2h_untagged(elf_bss);
+    host_end = (uintptr_t) g2h_untagged(last_bss);
     host_map_start = REAL_HOST_PAGE_ALIGN(host_start);
 
     if (host_map_start < host_end) {
@@ -2171,7 +2171,7 @@ static void pgb_have_guest_base(const char *image_name, abi_ulong guest_loaddr,
     }
 
     /* Reserve the address space for the binary, or reserved_va. */
-    test = g2h(guest_loaddr);
+    test = g2h_untagged(guest_loaddr);
     addr = mmap(test, guest_hiaddr - guest_loaddr, PROT_NONE, flags, -1, 0);
     if (test != addr) {
         pgb_fail_in_use(image_name);
@@ -2393,7 +2393,7 @@ static void pgb_reserved_va(const char *image_name, abi_ulong guest_loaddr,
 
     /* Reserve the memory on the host. */
     assert(guest_base != 0);
-    test = g2h(0);
+    test = g2h_untagged(0);
     addr = mmap(test, reserved_va, PROT_NONE, flags, -1, 0);
     if (addr == MAP_FAILED || addr != test) {
         error_report("Unable to reserve 0x%lx bytes of virtual address "