diff --git a/linux-user/aarch64/target_mman.h b/linux-user/aarch64/target_mman.h
index 4d3eecfb26..69ec5d5739 100644
--- a/linux-user/aarch64/target_mman.h
+++ b/linux-user/aarch64/target_mman.h
@@ -14,6 +14,9 @@
  */
 #define TASK_UNMAPPED_BASE      (1ull << (48 - 2))
 
+/* arch/arm64/include/asm/elf.h */
+#define ELF_ET_DYN_BASE         TARGET_PAGE_ALIGN((1ull << 48) / 3 * 2)
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/alpha/target_mman.h b/linux-user/alpha/target_mman.h
index c90b493711..8edfe2b88c 100644
--- a/linux-user/alpha/target_mman.h
+++ b/linux-user/alpha/target_mman.h
@@ -28,6 +28,9 @@
  */
 #define TASK_UNMAPPED_BASE      0x20000000000ull
 
+/* arch/alpha/include/asm/elf.h */
+#define ELF_ET_DYN_BASE         (TASK_UNMAPPED_BASE + 0x1000000)
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/arm/target_mman.h b/linux-user/arm/target_mman.h
index 76275b2c7e..51005da869 100644
--- a/linux-user/arm/target_mman.h
+++ b/linux-user/arm/target_mman.h
@@ -6,4 +6,7 @@
  */
 #define TASK_UNMAPPED_BASE   0x40000000
 
+/* arch/arm/include/asm/elf.h */
+#define ELF_ET_DYN_BASE      0x00400000
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/cris/target_mman.h b/linux-user/cris/target_mman.h
index 9df7b1eda5..9ace8ac292 100644
--- a/linux-user/cris/target_mman.h
+++ b/linux-user/cris/target_mman.h
@@ -7,4 +7,7 @@
  */
 #define TASK_UNMAPPED_BASE TARGET_PAGE_ALIGN(0xb0000000 / 3)
 
+/* arch/cris/include/uapi/asm/elf.h */
+#define ELF_ET_DYN_BASE    (TASK_UNMAPPED_BASE * 2)
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/hexagon/target_mman.h b/linux-user/hexagon/target_mman.h
index c5ae336e07..e6b5e2ca36 100644
--- a/linux-user/hexagon/target_mman.h
+++ b/linux-user/hexagon/target_mman.h
@@ -8,4 +8,7 @@
  */
 #define TASK_UNMAPPED_BASE   0x40000000
 
+/* arch/hexagon/include/asm/elf.h */
+#define ELF_ET_DYN_BASE      0x08000000
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/hppa/target_mman.h b/linux-user/hppa/target_mman.h
index 6459e7dbdd..ccda46e842 100644
--- a/linux-user/hppa/target_mman.h
+++ b/linux-user/hppa/target_mman.h
@@ -27,6 +27,9 @@
 /* arch/parisc/include/asm/processor.h: DEFAULT_MAP_BASE32 */
 #define TASK_UNMAPPED_BASE      0x40000000
 
+/* arch/parisc/include/asm/elf.h */
+#define ELF_ET_DYN_BASE         (TASK_UNMAPPED_BASE + 0x01000000)
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/i386/target_mman.h b/linux-user/i386/target_mman.h
index cc3382007f..e3b8e1eaa6 100644
--- a/linux-user/i386/target_mman.h
+++ b/linux-user/i386/target_mman.h
@@ -11,4 +11,7 @@
  */
 #define TASK_UNMAPPED_BASE    0x40000000
 
+/* arch/x86/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       0x00400000
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/loongarch64/target_mman.h b/linux-user/loongarch64/target_mman.h
index d70e44d44c..8c2a3d5596 100644
--- a/linux-user/loongarch64/target_mman.h
+++ b/linux-user/loongarch64/target_mman.h
@@ -6,4 +6,7 @@
 #define TASK_UNMAPPED_BASE \
     TARGET_PAGE_ALIGN((1ull << TARGET_VIRT_ADDR_SPACE_BITS) / 3)
 
+/* arch/loongarch/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       (TASK_UNMAPPED_BASE * 2)
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/m68k/target_mman.h b/linux-user/m68k/target_mman.h
index d3eceb663b..20cfe750c5 100644
--- a/linux-user/m68k/target_mman.h
+++ b/linux-user/m68k/target_mman.h
@@ -1,4 +1,6 @@
 /* arch/m68k/include/asm/processor.h */
 #define TASK_UNMAPPED_BASE      0xC0000000
+/* arch/m68k/include/asm/elf.h */
+#define ELF_ET_DYN_BASE         0xD0000000
 
 #include "../generic/target_mman.h"
diff --git a/linux-user/microblaze/target_mman.h b/linux-user/microblaze/target_mman.h
index ffee869db4..6b3dd54f89 100644
--- a/linux-user/microblaze/target_mman.h
+++ b/linux-user/microblaze/target_mman.h
@@ -6,4 +6,7 @@
  */
 #define TASK_UNMAPPED_BASE      0x48000000
 
+/* arch/microblaze/include/uapi/asm/elf.h */
+#define ELF_ET_DYN_BASE         0x08000000
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/mips/target_mman.h b/linux-user/mips/target_mman.h
index fe1eec2d0b..b84fe1e8a8 100644
--- a/linux-user/mips/target_mman.h
+++ b/linux-user/mips/target_mman.h
@@ -21,6 +21,9 @@
 #define TASK_UNMAPPED_BASE \
     TARGET_PAGE_ALIGN((1ull << TARGET_VIRT_ADDR_SPACE_BITS) / 3)
 
+/* arch/mips/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       (TASK_UNMAPPED_BASE * 2)
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/nios2/target_mman.h b/linux-user/nios2/target_mman.h
index ce18f4f871..ab16ad4f03 100644
--- a/linux-user/nios2/target_mman.h
+++ b/linux-user/nios2/target_mman.h
@@ -5,4 +5,7 @@
  */
 #define TASK_UNMAPPED_BASE    TARGET_PAGE_ALIGN(0x7FFF0000 / 3)
 
+/* arch/nios2/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       0xD0000000
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/openrisc/target_mman.h b/linux-user/openrisc/target_mman.h
index f1aaad809d..243c1d5f26 100644
--- a/linux-user/openrisc/target_mman.h
+++ b/linux-user/openrisc/target_mman.h
@@ -5,4 +5,7 @@
  */
 #define TASK_UNMAPPED_BASE      0x30000000
 
+/* arch/openrisc/include/asm/elf.h */
+#define ELF_ET_DYN_BASE         0x08000000
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/ppc/target_mman.h b/linux-user/ppc/target_mman.h
index 04f99c6077..646d1ccae7 100644
--- a/linux-user/ppc/target_mman.h
+++ b/linux-user/ppc/target_mman.h
@@ -17,6 +17,13 @@
 #define TASK_UNMAPPED_BASE      0x40000000
 #endif
 
+/* arch/powerpc/include/asm/elf.h */
+#ifdef TARGET_PPC64
+#define ELF_ET_DYN_BASE         0x100000000ull
+#else
+#define ELF_ET_DYN_BASE         0x000400000
+#endif
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/riscv/target_mman.h b/linux-user/riscv/target_mman.h
index 0f06dadbd4..3049bcc67d 100644
--- a/linux-user/riscv/target_mman.h
+++ b/linux-user/riscv/target_mman.h
@@ -5,4 +5,7 @@
 #define TASK_UNMAPPED_BASE \
     TARGET_PAGE_ALIGN((1ull << (TARGET_VIRT_ADDR_SPACE_BITS - 1)) / 3)
 
+/* arch/riscv/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       (TASK_UNMAPPED_BASE * 2)
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/s390x/target_mman.h b/linux-user/s390x/target_mman.h
index 40d149b329..c82435e381 100644
--- a/linux-user/s390x/target_mman.h
+++ b/linux-user/s390x/target_mman.h
@@ -8,4 +8,14 @@
  */
 #define TASK_UNMAPPED_BASE      (1ull << 41)
 
+/*
+ * arch/s390/include/asm/elf.h:
+ * ELF_ET_DYN_BASE              (STACK_TOP / 3 * 2) & ~((1UL << 32) - 1)
+ *
+ * arch/s390/include/asm/processor.h:
+ * STACK_TOP                    VDSO_LIMIT - VDSO_SIZE - PAGE_SIZE
+ * VDSO_LIMIT                   _REGION2_SIZE
+ */
+#define ELF_ET_DYN_BASE         (((1ull << 42) / 3 * 2) & ~0xffffffffull)
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/sh4/target_mman.h b/linux-user/sh4/target_mman.h
index bbbc223398..dd9016081e 100644
--- a/linux-user/sh4/target_mman.h
+++ b/linux-user/sh4/target_mman.h
@@ -2,4 +2,7 @@
 #define TASK_UNMAPPED_BASE \
     TARGET_PAGE_ALIGN((1u << TARGET_VIRT_ADDR_SPACE_BITS) / 3)
 
+/* arch/sh/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       (TASK_UNMAPPED_BASE * 2)
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/sparc/target_mman.h b/linux-user/sparc/target_mman.h
index 692ebf9dd7..696ca73fe4 100644
--- a/linux-user/sparc/target_mman.h
+++ b/linux-user/sparc/target_mman.h
@@ -19,6 +19,17 @@
 #define TASK_UNMAPPED_BASE      (1ull << (TARGET_VIRT_ADDR_SPACE_BITS - 2))
 #endif
 
+/*
+ * arch/sparc/include/asm/elf_64.h
+ * Except that COMPAT_ELF_ET_DYN_BASE exactly matches TASK_UNMAPPED_BASE,
+ * so move it up a bit.
+ */
+#ifdef TARGET_ABI32
+#define ELF_ET_DYN_BASE         0x78000000
+#else
+#define ELF_ET_DYN_BASE         0x0000010000000000ull
+#endif
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/user-mmap.h b/linux-user/user-mmap.h
index bae49059e0..5dd48a458d 100644
--- a/linux-user/user-mmap.h
+++ b/linux-user/user-mmap.h
@@ -20,6 +20,7 @@
 
 extern abi_ulong task_unmapped_base;
 extern abi_ulong mmap_next_start;
+extern abi_ulong elf_et_dyn_base;
 
 int target_mprotect(abi_ulong start, abi_ulong len, int prot);
 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
diff --git a/linux-user/x86_64/target_mman.h b/linux-user/x86_64/target_mman.h
index f9ff652b37..48fbf20b42 100644
--- a/linux-user/x86_64/target_mman.h
+++ b/linux-user/x86_64/target_mman.h
@@ -10,4 +10,7 @@
 #define TASK_UNMAPPED_BASE \
     TARGET_PAGE_ALIGN((1ull << TARGET_VIRT_ADDR_SPACE_BITS) / 3)
 
+/* arch/x86/include/asm/elf.h */
+#define ELF_ET_DYN_BASE       (TASK_UNMAPPED_BASE * 2)
+
 #include "../generic/target_mman.h"
diff --git a/linux-user/xtensa/target_mman.h b/linux-user/xtensa/target_mman.h
index c4f671adb7..8fa6337a97 100644
--- a/linux-user/xtensa/target_mman.h
+++ b/linux-user/xtensa/target_mman.h
@@ -20,6 +20,10 @@
  */
 #define TASK_UNMAPPED_BASE      (1u << (TARGET_VIRT_ADDR_SPACE_BITS - 1))
 
+/* arch/xtensa/include/asm/elf.h */
+#define ELF_ET_DYN_BASE \
+    TARGET_PAGE_ALIGN((1u << TARGET_VIRT_ADDR_SPACE_BITS) / 3)
+
 #include "../generic/target_mman.h"
 
 #endif
diff --git a/linux-user/main.c b/linux-user/main.c
index c207b783d5..2b6f3f22c7 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -845,6 +845,21 @@ int main(int argc, char **argv, char **envp)
     }
     mmap_next_start = task_unmapped_base;
 
+    /* Similarly for elf_et_dyn_base. */
+    if (reserved_va) {
+        if (LESS(ELF_ET_DYN_BASE, reserved_va)) {
+            elf_et_dyn_base = ELF_ET_DYN_BASE;
+        } else {
+            /* The most common default formula is TASK_SIZE / 3 * 2. */
+            elf_et_dyn_base = TARGET_PAGE_ALIGN(reserved_va / 3) * 2;
+        }
+    } else if (LESS(ELF_ET_DYN_BASE, UINTPTR_MAX)) {
+        elf_et_dyn_base = ELF_ET_DYN_BASE;
+    } else {
+        /* 32-bit host: pick something medium size. */
+        elf_et_dyn_base = 0x18000000;
+    }
+
 #undef LESS
 
     {
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 84436d45c8..949c4090f3 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -301,6 +301,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
 
 abi_ulong task_unmapped_base;
 abi_ulong mmap_next_start;
+abi_ulong elf_et_dyn_base;
 
 /*
  * Subroutine of mmap_find_vma, used when we have pre-allocated
