implement host-controlled memory mapping for #261

include/uc_priv.h

@@ -48,6 +48,8 @@ typedef void (*uc_args_uc_u64_t)(struct uc_struct *, uint64_t addr);
 
 typedef MemoryRegion* (*uc_args_uc_ram_size_t)(struct uc_struct*,  ram_addr_t begin, size_t size, uint32_t perms);
 
+typedef MemoryRegion* (*uc_args_uc_ram_size_ptr_t)(struct uc_struct*,  ram_addr_t begin, size_t size, void *ptr);
+
 typedef void (*uc_mem_unmap_t)(struct uc_struct*, MemoryRegion *mr);
 
 typedef void (*uc_readonly_mem_t)(MemoryRegion *mr, bool readonly);
@@ -97,6 +99,7 @@ struct uc_struct {
     uc_args_tcg_enable_t tcg_enabled;
     uc_args_uc_long_t tcg_exec_init;
     uc_args_uc_ram_size_t memory_map;
+    uc_args_uc_ram_size_ptr_t memory_map_ptr;
     uc_mem_unmap_t memory_unmap;
     uc_readonly_mem_t readonly_mem;
     uc_mem_redirect_t mem_redirect;

include/unicorn/unicorn.h

@@ -446,6 +446,24 @@ typedef enum uc_prot {
 UNICORN_EXPORT
 uc_err uc_mem_map(uc_engine *uc, uint64_t address, size_t size, uint32_t perms);
 
+/*
+ Map existing host memory in for emulation.
+ This API adds a memory region that can be used by emulation.
+
+ @uc: handle returned by uc_open()
+ @address: starting address of the new memory region to be mapped in.
+    This address must be aligned to 4KB, or this will return with UC_ERR_ARG error.
+ @size: size of the new memory region to be mapped in.
+    This size must be multiple of 4KB, or this will return with UC_ERR_ARG error.
+ @ptr: pointer to host memory backing the newly mapped memory. Existing host
+    memory permissions are preserved.
+
+ @return UC_ERR_OK on success, or other value on failure (refer to uc_err enum
+ for detailed error).
+*/
+UNICORN_EXPORT
+uc_err uc_mem_map_ptr(uc_engine *uc, uint64_t address, size_t size, void *ptr);
+
 /*
  Unmap a region of emulation memory.
  This API deletes a memory mapping from the emulation memory space.

qemu/aarch64.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_aarch64
 #define tb_cleanup tb_cleanup_aarch64
 #define memory_map memory_map_aarch64
+#define memory_map_ptr memory_map_ptr_aarch64
 #define memory_unmap memory_unmap_aarch64
 #define memory_free memory_free_aarch64
 #define helper_raise_exception helper_raise_exception_aarch64

qemu/arm.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_arm
 #define tb_cleanup tb_cleanup_arm
 #define memory_map memory_map_arm
+#define memory_map_ptr memory_map_ptr_arm
 #define memory_unmap memory_unmap_arm
 #define memory_free memory_free_arm
 #define helper_raise_exception helper_raise_exception_arm

qemu/header_gen.py

@@ -14,6 +14,7 @@ symbols = (
     'phys_mem_clean',
     'tb_cleanup',
     'memory_map',
+    'memory_map_ptr',
     'memory_unmap',
     'memory_free',
     'helper_raise_exception',

qemu/include/exec/memory.h

@@ -939,6 +939,7 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
 void memory_register_types(struct uc_struct *uc);
 
 MemoryRegion *memory_map(struct uc_struct *uc, ram_addr_t begin, size_t size, uint32_t perms);
+MemoryRegion *memory_map_ptr(struct uc_struct *uc, ram_addr_t begin, size_t size, void *ptr);
 void memory_unmap(struct uc_struct *uc, MemoryRegion *mr);
 int memory_free(struct uc_struct *uc);
 

qemu/m68k.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_m68k
 #define tb_cleanup tb_cleanup_m68k
 #define memory_map memory_map_m68k
+#define memory_map_ptr memory_map_ptr_m68k
 #define memory_unmap memory_unmap_m68k
 #define memory_free memory_free_m68k
 #define helper_raise_exception helper_raise_exception_m68k

qemu/memory.c

@@ -48,6 +48,23 @@ MemoryRegion *memory_map(struct uc_struct *uc, ram_addr_t begin, size_t size, ui
     return ram;
 }
 
+MemoryRegion *memory_map_ptr(struct uc_struct *uc, ram_addr_t begin, size_t size, void *ptr)
+{
+    MemoryRegion *ram = g_new(MemoryRegion, 1);
+
+    memory_region_init_ram_ptr(uc, ram, NULL, "pc.ram", size, ptr);
+    if (ram->ram_addr == -1)
+        // out of memory
+        return NULL;
+
+    memory_region_add_subregion(get_system_memory(uc), begin, ram);
+
+    if (uc->current_cpu)
+        tlb_flush(uc->current_cpu, 1);
+
+    return ram;
+}
+
 void memory_unmap(struct uc_struct *uc, MemoryRegion *mr)
 {
     int i;

qemu/mips.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_mips
 #define tb_cleanup tb_cleanup_mips
 #define memory_map memory_map_mips
+#define memory_map_ptr memory_map_ptr_mips
 #define memory_unmap memory_unmap_mips
 #define memory_free memory_free_mips
 #define helper_raise_exception helper_raise_exception_mips

qemu/mips64.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_mips64
 #define tb_cleanup tb_cleanup_mips64
 #define memory_map memory_map_mips64
+#define memory_map_ptr memory_map_ptr_mips64
 #define memory_unmap memory_unmap_mips64
 #define memory_free memory_free_mips64
 #define helper_raise_exception helper_raise_exception_mips64

qemu/mips64el.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_mips64el
 #define tb_cleanup tb_cleanup_mips64el
 #define memory_map memory_map_mips64el
+#define memory_map_ptr memory_map_ptr_mips64el
 #define memory_unmap memory_unmap_mips64el
 #define memory_free memory_free_mips64el
 #define helper_raise_exception helper_raise_exception_mips64el

qemu/mipsel.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_mipsel
 #define tb_cleanup tb_cleanup_mipsel
 #define memory_map memory_map_mipsel
+#define memory_map_ptr memory_map_ptr_mipsel
 #define memory_unmap memory_unmap_mipsel
 #define memory_free memory_free_mipsel
 #define helper_raise_exception helper_raise_exception_mipsel

qemu/sparc.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_sparc
 #define tb_cleanup tb_cleanup_sparc
 #define memory_map memory_map_sparc
+#define memory_map_ptr memory_map_ptr_sparc
 #define memory_unmap memory_unmap_sparc
 #define memory_free memory_free_sparc
 #define helper_raise_exception helper_raise_exception_sparc

qemu/sparc64.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_sparc64
 #define tb_cleanup tb_cleanup_sparc64
 #define memory_map memory_map_sparc64
+#define memory_map_ptr memory_map_ptr_sparc64
 #define memory_unmap memory_unmap_sparc64
 #define memory_free memory_free_sparc64
 #define helper_raise_exception helper_raise_exception_sparc64

qemu/unicorn_common.h

@@ -73,6 +73,7 @@ static inline void uc_common_init(struct uc_struct* uc)
     uc->pause_all_vcpus = pause_all_vcpus;
     uc->vm_start = vm_start;
     uc->memory_map = memory_map;
+    uc->memory_map_ptr = memory_map_ptr;
     uc->memory_unmap = memory_unmap;
     uc->readonly_mem = memory_region_set_readonly;
 

qemu/x86_64.h

@@ -8,6 +8,7 @@
 #define phys_mem_clean phys_mem_clean_x86_64
 #define tb_cleanup tb_cleanup_x86_64
 #define memory_map memory_map_x86_64
+#define memory_map_ptr memory_map_ptr_x86_64
 #define memory_unmap memory_unmap_x86_64
 #define memory_free memory_free_x86_64
 #define helper_raise_exception helper_raise_exception_x86_64

tests/unit/Makefile

@@ -4,7 +4,7 @@ CFLAGS += -L ../../
 CFLAGS += -lcmocka -lunicorn
 CFLAGS += -I ../../include
 
-ALL_TESTS = test_sanity test_x86 test_mem_map
+ALL_TESTS = test_sanity test_x86 test_mem_map test_mem_map_ptr
 
 .PHONY: all
 all: ${ALL_TESTS}
@@ -23,9 +23,7 @@ test: ${ALL_TESTS}
 test_sanity: test_sanity.c
 test_x86: test_x86.c
 test_mem_map: test_mem_map.c
+test_mem_map_ptr: test_mem_map_ptr.c
 
 ${ALL_TESTS}:
 	gcc ${CFLAGS} -o $@ $^
-
-
-

tests/unit/test_mem_map_ptr.c

@@ -0,0 +1,75 @@
+/**
+ * Unicorn memory API tests
+ *
+ * This tests manual pointer-backed memory.
+ */
+#include "unicorn_test.h"
+#include <stdio.h>
+#include <string.h>
+
+/* Called before every test to set up a new instance */
+static int setup(void **state)
+{
+    uc_engine *uc;
+
+    uc_assert_success(uc_open(UC_ARCH_X86, UC_MODE_32, &uc));
+
+    *state = uc;
+    return 0;
+}
+
+/* Called after every test to clean up */
+static int teardown(void **state)
+{
+    uc_engine *uc = *state;
+
+    uc_assert_success(uc_close(uc));
+
+    *state = NULL;
+    return 0;
+}
+
+/******************************************************************************/
+
+
+/**
+ * A basic test showing mapping of memory, and reading/writing it
+ */
+static void test_basic(void **state)
+{
+    uc_engine *uc = *state;
+    const uint64_t mem_start = 0x1000;
+    const uint64_t mem_len   = 0x1000;
+    const uint64_t test_addr = mem_start;
+
+    void *host_mem = calloc(1, mem_len);
+
+    /* Map a region */
+    uc_assert_success(uc_mem_map_ptr(uc, mem_start, mem_len, host_mem));
+
+    /* Write some data to it */
+    uc_assert_success(uc_mem_write(uc, test_addr, "test", 4));
+
+    uint8_t buf[4];
+    memset(buf, 0xCC, sizeof(buf));
+
+    /* Read it back */
+    uc_assert_success(uc_mem_read(uc, test_addr, buf, sizeof(buf)));
+
+    /* And make sure it matches what we expect */
+    assert_memory_equal(buf, "test", 4);
+
+    /* Unmap the region */
+    uc_assert_success(uc_mem_unmap(uc, mem_start, mem_len));
+
+    assert_memory_equal(buf, host_mem, 4);
+}
+
+int main(void) {
+#define test(x)     cmocka_unit_test_setup_teardown(x, setup, teardown)
+    const struct CMUnitTest tests[] = {
+        test(test_basic),
+    };
+#undef test
+    return cmocka_run_group_tests(tests, NULL, NULL);
+}

uc.c

@@ -570,8 +570,8 @@ static uc_err _hook_mem_access(uc_engine *uc, uc_hook_type type,
     return UC_ERR_OK;
 }
 
-UNICORN_EXPORT
-uc_err uc_mem_map(uc_engine *uc, uint64_t address, size_t size, uint32_t perms)
+// common setup/error checking shared between uc_mem_map and uc_mem_map_ptr
+static uc_err mem_map_start(uc_engine *uc, uint64_t address, size_t size, uint32_t perms)
 {
     MemoryRegion **regions;
 
@@ -600,7 +600,13 @@ uc_err uc_mem_map(uc_engine *uc, uint64_t address, size_t size, uint32_t perms)
         uc->mapped_blocks = regions;
     }
 
-    uc->mapped_blocks[uc->mapped_block_count] = uc->memory_map(uc, address, size, perms);
+    return UC_ERR_OK;
+}
+
+// common final step shared by uc_mem_map and uc_mem_map_ptr
+static uc_err mem_map_finish(uc_engine *uc, MemoryRegion *block)
+{
+    uc->mapped_blocks[uc->mapped_block_count] = block;
     if (uc->mapped_blocks[uc->mapped_block_count] == NULL)
         return UC_ERR_NOMEM;
 
@@ -609,6 +615,29 @@ uc_err uc_mem_map(uc_engine *uc, uint64_t address, size_t size, uint32_t perms)
     return UC_ERR_OK;
 }
 
+UNICORN_EXPORT
+uc_err uc_mem_map(uc_engine *uc, uint64_t address, size_t size, uint32_t perms)
+{
+    uc_err err;
+    if ((err = mem_map_start(uc, address, size, perms)) != UC_ERR_OK)
+        return err;
+
+    return mem_map_finish(uc, uc->memory_map(uc, address, size, perms));
+}
+
+UNICORN_EXPORT
+uc_err uc_mem_map_ptr(uc_engine *uc, uint64_t address, size_t size, void *ptr)
+{
+    if (ptr == NULL)
+        return UC_ERR_ARG;
+
+    uc_err err;
+    if ((err = mem_map_start(uc, address, size, UC_PROT_ALL)) != UC_ERR_OK)
+        return err;
+
+    return mem_map_finish(uc, uc->memory_map_ptr(uc, address, size, ptr));
+}
+
 // Create a backup copy of the indicated MemoryRegion.
 // Generally used in prepartion for splitting a MemoryRegion.
 static uint8_t *copy_region(struct uc_struct *uc, MemoryRegion *mr)