[Qemu-devel] [PATCH 7/8] fw_cfg: Use void *, size_t instead of uint8_t *, uint32_t for blobs

[Markus Armbruster <armbru@redhat.com>]

Many callers pass size_t, which gets silently truncated to uint32_t.
Harmless, because all practical sizes are well below 4GiB.  Clean it
up anyway.  Size overflow now fails assertions.

Bonus: saves a whole bunch of silly casts.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 hw/fw_cfg.c  | 31 ++++++++++++++++---------------
 hw/fw_cfg.h  |  8 ++++----
 hw/pc.c      | 13 ++++++-------
 trace-events |  2 +-
 4 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/hw/fw_cfg.c b/hw/fw_cfg.c
index 3d6dd5f..699383c 100644
--- a/hw/fw_cfg.c
+++ b/hw/fw_cfg.c
@@ -373,23 +373,23 @@ static const VMStateDescription vmstate_fw_cfg = {
     }
 };
 
-void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, uint8_t *data, uint32_t len)
+void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
 {
     int arch = !!(key & FW_CFG_ARCH_LOCAL);
 
     key &= FW_CFG_ENTRY_MASK;
 
-    assert(key < FW_CFG_MAX_ENTRY);
+    assert(key < FW_CFG_MAX_ENTRY && len < UINT32_MAX);
 
     s->entries[arch][key].data = data;
-    s->entries[arch][key].len = len;
+    s->entries[arch][key].len = (uint32_t)len;
 }
 
 void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value)
 {
     size_t sz = strlen(value) + 1;
 
-    return fw_cfg_add_bytes(s, key, (uint8_t *)g_memdup(value, sz), sz);
+    return fw_cfg_add_bytes(s, key, g_memdup(value, sz), sz);
 }
 
 void fw_cfg_add_i16(FWCfgState *s, uint16_t key, uint16_t value)
@@ -398,7 +398,7 @@ void fw_cfg_add_i16(FWCfgState *s, uint16_t key, uint16_t value)
 
     copy = g_malloc(sizeof(value));
     *copy = cpu_to_le16(value);
-    fw_cfg_add_bytes(s, key, (uint8_t *)copy, sizeof(value));
+    fw_cfg_add_bytes(s, key, copy, sizeof(value));
 }
 
 void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value)
@@ -407,7 +407,7 @@ void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value)
 
     copy = g_malloc(sizeof(value));
     *copy = cpu_to_le32(value);
-    fw_cfg_add_bytes(s, key, (uint8_t *)copy, sizeof(value));
+    fw_cfg_add_bytes(s, key, copy, sizeof(value));
 }
 
 void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value)
@@ -416,11 +416,11 @@ void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value)
 
     copy = g_malloc(sizeof(value));
     *copy = cpu_to_le64(value);
-    fw_cfg_add_bytes(s, key, (uint8_t *)copy, sizeof(value));
+    fw_cfg_add_bytes(s, key, copy, sizeof(value));
 }
 
 void fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
-                         void *callback_opaque, uint8_t *data, size_t len)
+                         void *callback_opaque, void *data, size_t len)
 {
     int arch = !!(key & FW_CFG_ARCH_LOCAL);
 
@@ -428,23 +428,24 @@ void fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
 
     key &= FW_CFG_ENTRY_MASK;
 
-    assert(key < FW_CFG_MAX_ENTRY && len <= 65535);
+    assert(key < FW_CFG_MAX_ENTRY && len <= UINT32_MAX);
 
     s->entries[arch][key].data = data;
-    s->entries[arch][key].len = len;
+    s->entries[arch][key].len = (uint32_t)len;
     s->entries[arch][key].callback_opaque = callback_opaque;
     s->entries[arch][key].callback = callback;
 }
 
-void fw_cfg_add_file(FWCfgState *s,  const char *filename, uint8_t *data,
-                     uint32_t len)
+void fw_cfg_add_file(FWCfgState *s,  const char *filename,
+                     void *data, size_t len)
 {
     int i, index;
+    size_t dsize;
 
     if (!s->files) {
-        int dsize = sizeof(uint32_t) + sizeof(FWCfgFile) * FW_CFG_FILE_SLOTS;
+        dsize = sizeof(uint32_t) + sizeof(FWCfgFile) * FW_CFG_FILE_SLOTS;
         s->files = g_malloc0(dsize);
-        fw_cfg_add_bytes(s, FW_CFG_FILE_DIR, (uint8_t*)s->files, dsize);
+        fw_cfg_add_bytes(s, FW_CFG_FILE_DIR, s->files, dsize);
     }
 
     index = be32_to_cpu(s->files->count);
@@ -498,7 +499,7 @@ FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
     if (data_addr) {
         sysbus_mmio_map(d, 1, data_addr);
     }
-    fw_cfg_add_bytes(s, FW_CFG_SIGNATURE, (uint8_t *)"QEMU", 4);
+    fw_cfg_add_bytes(s, FW_CFG_SIGNATURE, (char *)"QEMU", 4);
     fw_cfg_add_bytes(s, FW_CFG_UUID, qemu_uuid, 16);
     fw_cfg_add_i16(s, FW_CFG_NOGRAPHIC, (uint16_t)(display_type == DT_NOGRAPHIC));
     fw_cfg_add_i16(s, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
diff --git a/hw/fw_cfg.h b/hw/fw_cfg.h
index c2c57cd..05c8df1 100644
--- a/hw/fw_cfg.h
+++ b/hw/fw_cfg.h
@@ -54,15 +54,15 @@ typedef struct FWCfgFiles {
 typedef void (*FWCfgCallback)(void *opaque, uint8_t *data);
 
 typedef struct FWCfgState FWCfgState;
-void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, uint8_t *data, uint32_t len);
+void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len);
 void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value);
 void fw_cfg_add_i16(FWCfgState *s, uint16_t key, uint16_t value);
 void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value);
 void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value);
 void fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
-                         void *callback_opaque, uint8_t *data, size_t len);
-void fw_cfg_add_file(FWCfgState *s, const char *filename, uint8_t *data,
-                     uint32_t len);
+                         void *callback_opaque, void *data, size_t len);
+void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data,
+                     size_t len);
 FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
                         hwaddr crl_addr, hwaddr data_addr);
 
diff --git a/hw/pc.c b/hw/pc.c
index 34cf79d..8fc69db 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -563,19 +563,18 @@ static void *bochs_bios_init(void)
 
     fw_cfg_add_i32(fw_cfg, FW_CFG_ID, 1);
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
-    fw_cfg_add_bytes(fw_cfg, FW_CFG_ACPI_TABLES, (uint8_t *)acpi_tables,
-                     acpi_tables_len);
+    fw_cfg_add_bytes(fw_cfg, FW_CFG_ACPI_TABLES,
+                     acpi_tables, acpi_tables_len);
     fw_cfg_add_i32(fw_cfg, FW_CFG_IRQ0_OVERRIDE, kvm_allows_irq0_override());
 
     smbios_table = smbios_get_table(&smbios_len);
     if (smbios_table)
         fw_cfg_add_bytes(fw_cfg, FW_CFG_SMBIOS_ENTRIES,
                          smbios_table, smbios_len);
-    fw_cfg_add_bytes(fw_cfg, FW_CFG_E820_TABLE, (uint8_t *)&e820_table,
-                     sizeof(e820_table));
+    fw_cfg_add_bytes(fw_cfg, FW_CFG_E820_TABLE,
+                     &e820_table, sizeof(e820_table));
 
-    fw_cfg_add_bytes(fw_cfg, FW_CFG_HPET, (uint8_t *)&hpet_cfg,
-                     sizeof(struct hpet_fw_config));
+    fw_cfg_add_bytes(fw_cfg, FW_CFG_HPET, &hpet_cfg, sizeof(hpet_cfg));
     /* allocate memory for the NUMA channel: one (64bit) word for the number
      * of nodes, one word for each VCPU->node and one word for each node to
      * hold the amount of memory.
@@ -593,7 +592,7 @@ static void *bochs_bios_init(void)
     for (i = 0; i < nb_numa_nodes; i++) {
         numa_fw_cfg[max_cpus + 1 + i] = cpu_to_le64(node_mem[i]);
     }
-    fw_cfg_add_bytes(fw_cfg, FW_CFG_NUMA, (uint8_t *)numa_fw_cfg,
+    fw_cfg_add_bytes(fw_cfg, FW_CFG_NUMA, numa_fw_cfg,
                      (1 + max_cpus + nb_numa_nodes) * sizeof(*numa_fw_cfg));
 
     return fw_cfg;
diff --git a/trace-events b/trace-events
index cf76a11..7de9106 100644
--- a/trace-events
+++ b/trace-events
@@ -172,7 +172,7 @@ fw_cfg_write(void *s, uint8_t value) "%p %d"
 fw_cfg_select(void *s, uint16_t key, int ret) "%p key %d = %d"
 fw_cfg_read(void *s, uint8_t ret) "%p = %d"
 fw_cfg_add_file_dupe(void *s, char *name) "%p %s"
-fw_cfg_add_file(void *s, int index, char *name, uint32_t len) "%p #%d: %s (%d bytes)"
+fw_cfg_add_file(void *s, int index, char *name, size_t len) "%p #%d: %s (%zd bytes)"
 
 # hw/hd-geometry.c
 hd_geometry_lchs_guess(void *bs, int cyls, int heads, int secs) "bs %p LCHS %d %d %d"
-- 
1.7.11.7