1 files changed, 28 insertions, 2 deletions

diff --git a/linux-user/user-mmap.h b/linux-user/user-mmap.h
index 3fc986f92f..0f4883eb57 100644
--- a/linux-user/user-mmap.h
+++ b/linux-user/user-mmap.h
@@ -18,6 +18,34 @@
 #ifndef LINUX_USER_USER_MMAP_H
 #define LINUX_USER_USER_MMAP_H
 
+/*
+ * Guest parameters for the ADDR_COMPAT_LAYOUT personality
+ * (at present this is the only layout supported by QEMU).
+ *
+ * TASK_UNMAPPED_BASE: For mmap without hint (addr != 0), the search
+ * for unused virtual memory begins at TASK_UNMAPPED_BASE.
+ *
+ * ELF_ET_DYN_BASE: When the executable is ET_DYN (i.e. PIE), and requires
+ * an interpreter (i.e. not -static-pie), use ELF_ET_DYN_BASE instead of
+ * TASK_UNMAPPED_BASE for selecting the address of the executable.
+ * This provides some distance between the executable and the interpreter,
+ * which allows the initial brk to be placed immediately after the
+ * executable and also have room to grow.
+ *
+ * task_unmapped_base, elf_et_dyn_base: When the guest address space is
+ * limited via -R, the values of TASK_UNMAPPED_BASE and ELF_ET_DYN_BASE
+ * must be adjusted to fit.
+ */
+extern abi_ulong task_unmapped_base;
+extern abi_ulong elf_et_dyn_base;
+
+/*
+ * mmap_next_start: The base address for the next mmap without hint,
+ * increased after each successful map, starting at task_unmapped_base.
+ * This is an optimization within QEMU and not part of ADDR_COMPAT_LAYOUT.
+ */
+extern abi_ulong mmap_next_start;
+
 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
                      int flags, int fd, off_t offset);
@@ -26,8 +54,6 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
                        abi_ulong new_size, unsigned long flags,
                        abi_ulong new_addr);
 abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice);
-extern unsigned long last_brk;
-extern abi_ulong mmap_next_start;
 abi_ulong mmap_find_vma(abi_ulong, abi_ulong, abi_ulong);
 void mmap_fork_start(void);
 void mmap_fork_end(int child);