bugfix: 修正潜在的错误路径 (#64)

* bugfix: 修正潜在的错误路径

* 修正格式

.gitignore

@@ -12,3 +12,4 @@ user/sys_api_lib
 
 docs/_build
 draft
+cppcheck.xml

Makefile

@@ -5,6 +5,16 @@ ifeq ($(EMULATOR), )
 export EMULATOR=__NO_EMULATION__
 endif
 
+# 计算cpu核心数
+NPROCS:=1
+OS:=$(shell uname -s)
+
+ifeq ($(OS),Linux)
+  NPROCS:=$(shell grep -c ^processor /proc/cpuinfo)
+endif
+ifeq ($(OS),Darwin) # Assume Mac OS X
+  NPROCS:=$(shell system_profiler | awk '/Number Of CPUs/{print $4}{next;}')
+endif
 
 export ARCH=__x86_64__
 export ROOT_PATH=$(shell pwd)
@@ -59,5 +69,11 @@ clean:
 		cd .. ;\
 	done
 
+cppcheck-xml: 
+	cppcheck kernel user --platform=unix64 --std=c11 -I user/libs/ -I=kernel/ --force -j $(NPROCS) --xml 2> cppcheck.xml
+
+cppcheck:
+	cppcheck kernel user --platform=unix64 --std=c11 -I user/libs/ -I=kernel/ --force -j $(NPROCS)
+
 gdb:
 	gdb -n -x tools/.gdbinit

kernel/driver/disk/ahci/ahci.c

@@ -674,4 +674,5 @@ static long ahci_transfer(struct blk_gendisk *gd, long cmd, uint64_t base_addr,
  */
 static long ahci_ioctl(long cmd, long arg)
 {
+    return 0;
 }

kernel/driver/pci/msi.c

@@ -28,25 +28,29 @@ static __always_inline struct pci_msix_cap_t __msi_read_msix_cap_list(struct msi
     cap_list.next_off = (dw0 >> 8) & 0xff;
     cap_list.msg_ctrl = (dw0 >> 16) & 0xffff;
 
-    cap_list.dword1 = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x4);
+    cap_list.dword1 =
-    cap_list.dword2 = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x8);
+        pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x4);
+    cap_list.dword2 =
+        pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x8);
     return cap_list;
 }
 
 static __always_inline struct pci_msi_cap_t __msi_read_cap_list(struct msi_desc_t *msi_desc, uint32_t cap_off)
 {
-    struct pci_msi_cap_t cap_list;
+    struct pci_msi_cap_t cap_list = {0};
     uint32_t dw0;
     dw0 = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off);
     cap_list.cap_id = dw0 & 0xff;
     cap_list.next_off = (dw0 >> 8) & 0xff;
     cap_list.msg_ctrl = (dw0 >> 16) & 0xffff;
 
-    cap_list.msg_addr_lo = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x4);
+    cap_list.msg_addr_lo =
+        pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x4);
     uint16_t msg_data_off = 0xc;
     if (cap_list.msg_ctrl & (1 << 7)) // 64位
     {
-        cap_list.msg_addr_hi = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x8);
+        cap_list.msg_addr_hi =
+            pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x8);
     }
     else
     {
@@ -54,10 +58,14 @@ static __always_inline struct pci_msi_cap_t __msi_read_cap_list(struct msi_desc_
         msg_data_off = 0x8;
     }
 
-    cap_list.msg_data = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + msg_data_off) & 0xffff;
+    cap_list.msg_data = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func,
+                                        cap_off + msg_data_off) &
+                        0xffff;
 
-    cap_list.mask = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x10);
+    cap_list.mask =
-    cap_list.pending = pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x14);
+        pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x10);
+    cap_list.pending =
+        pci_read_config(msi_desc->pci_dev->bus, msi_desc->pci_dev->device, msi_desc->pci_dev->func, cap_off + 0x14);
 
     return cap_list;
 }
@@ -69,7 +77,8 @@ static __always_inline struct pci_msi_cap_t __msi_read_cap_list(struct msi_desc_
  * @param msix_cap msix capability list的结构体
  * @return int 错误码
  */
-static __always_inline int __msix_map_table(struct pci_device_structure_header_t *pci_dev, struct pci_msix_cap_t *msix_cap)
+static __always_inline int __msix_map_table(struct pci_device_structure_header_t *pci_dev,
+                                            struct pci_msix_cap_t *msix_cap)
 {
     // 计算bar寄存器的offset
     uint32_t bar_off = 0x10 + 4 * (msix_cap->dword1 & 0x7);
@@ -83,7 +92,8 @@ static __always_inline int __msix_map_table(struct pci_device_structure_header_t
     mmio_create(pci_dev->msix_mmio_size, VM_IO | VM_DONTCOPY, &pci_dev->msix_mmio_vaddr, &pci_dev->msix_mmio_size);
     pci_dev->msix_mmio_vaddr &= (~0xf);
     uint32_t bar = pci_read_config(pci_dev->bus, pci_dev->device, pci_dev->func, bar_off);
-    // kdebug("pci_dev->msix_mmio_vaddr=%#018lx, bar=%#010lx, table offset=%#010lx, table_size=%#010lx, mmio_size=%d", pci_dev->msix_mmio_vaddr, bar, pci_dev->msix_offset, pci_dev->msix_table_size, pci_dev->msix_mmio_size);
+    // kdebug("pci_dev->msix_mmio_vaddr=%#018lx, bar=%#010lx, table offset=%#010lx, table_size=%#010lx, mmio_size=%d",
+    // pci_dev->msix_mmio_vaddr, bar, pci_dev->msix_offset, pci_dev->msix_table_size, pci_dev->msix_mmio_size);
 
     // 将msix table映射到页表
     mm_map(&initial_mm, pci_dev->msix_mmio_vaddr, pci_dev->msix_mmio_size, bar);
@@ -98,7 +108,8 @@ static __always_inline int __msix_map_table(struct pci_device_structure_header_t
  */
 static __always_inline void __msix_set_entry(struct msi_desc_t *msi_desc)
 {
-    uint64_t *ptr = (uint64_t *)(msi_desc->pci_dev->msix_mmio_vaddr + msi_desc->pci_dev->msix_offset + msi_desc->msi_index * 16);
+    uint64_t *ptr =
+        (uint64_t *)(msi_desc->pci_dev->msix_mmio_vaddr + msi_desc->pci_dev->msix_offset + msi_desc->msi_index * 16);
     *ptr = ((uint64_t)(msi_desc->msg.address_hi) << 32) | (msi_desc->msg.address_lo);
     io_mfence();
     ++ptr;
@@ -177,7 +188,7 @@ int pci_enable_msi(struct msi_desc_t *msi_desc)
         // todo: disable intx
         // 使能msi-x
         tmp = pci_read_config(ptr->bus, ptr->device, ptr->func, cap_ptr); // 读取cap+0x0处的值
-        tmp |= (1 << 31);
+        tmp |= (1U << 31);
         pci_write_config(ptr->bus, ptr->device, ptr->func, cap_ptr, tmp);
     }
     else
@@ -191,7 +202,8 @@ int pci_enable_msi(struct msi_desc_t *msi_desc)
         pci_write_config(ptr->bus, ptr->device, ptr->func, cap_ptr + 0x4, (uint32_t)(message_addr & 0xffffffff));
 
         if (message_control & (1 << 7)) // 64位
-            pci_write_config(ptr->bus, ptr->device, ptr->func, cap_ptr + 0x8, (uint32_t)((message_addr >> 32) & 0xffffffff));
+            pci_write_config(ptr->bus, ptr->device, ptr->func, cap_ptr + 0x8,
+                             (uint32_t)((message_addr >> 32) & 0xffffffff));
 
         // 写入message data
 

kernel/driver/usb/xhci/xhci.c

@@ -807,7 +807,7 @@ static int xhci_reset_port(const int id, const int port)
     io_mfence();
     // 重置当前端口
     if (XHCI_PORT_IS_USB3(id, port))
-        xhci_write_op_reg32(id, port_status_offset + XHCI_PORT_PORTSC, (1 << 9) | (1 << 31));
+        xhci_write_op_reg32(id, port_status_offset + XHCI_PORT_PORTSC, (1 << 9) | (1U << 31));
     else
         xhci_write_op_reg32(id, port_status_offset + XHCI_PORT_PORTSC, (1 << 9) | (1 << 4));
 
@@ -825,7 +825,7 @@ static int xhci_reset_port(const int id, const int port)
             // QEMU对usb的模拟有bug，因此需要检测这里
 #ifdef __QEMU_EMULATION__
 
-        if (XHCI_PORT_IS_USB3(id, port) && (val & (1 << 31)) == 0)
+        if (XHCI_PORT_IS_USB3(id, port) && (val & (1U << 31)) == 0)
             break;
         else if (XHCI_PORT_IS_USB2(id, port) && (val & (1 << 4)) == 0)
             break;

kernel/driver/usb/xhci/xhci.h

@@ -8,7 +8,7 @@
 
 // ========== irq BEGIN ===========
 
-#define XHCI_IRQ_DONE (1 << 31) // 当command trb 的status的第31位被驱动程序置位时，表明该trb已经执行完成（这是由于xhci规定，第31位可以由驱动程序自行决定用途）
+#define XHCI_IRQ_DONE (1U << 31) // 当command trb 的status的第31位被驱动程序置位时，表明该trb已经执行完成（这是由于xhci规定，第31位可以由驱动程序自行决定用途）
 /**
  * @brief 每个xhci控制器的中断向量号
  *

kernel/filesystem/fat32/fat32.c

@@ -1,12 +1,12 @@
 #include "fat32.h"
+#include "fat_ent.h"
+#include <common/errno.h>
 #include <common/kprint.h>
+#include <common/spinlock.h>
+#include <common/stdio.h>
 #include <driver/disk/ahci/ahci.h>
 #include <filesystem/MBR.h>
-#include <common/spinlock.h>
 #include <mm/slab.h>
-#include <common/errno.h>
-#include <common/stdio.h>
-#include "fat_ent.h"
 
 struct vfs_super_block_operations_t fat32_sb_ops;
 struct vfs_dir_entry_operations_t fat32_dEntry_ops;
@@ -104,7 +104,9 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
                 {
                     if (js > dest_dentry->name_length && tmp_ldEntry->LDIR_Name1[x] == 0xffff)
                         continue;
-                    else if (js > dest_dentry->name_length || tmp_ldEntry->LDIR_Name1[x] != (uint16_t)(dest_dentry->name[js++])) // 文件名不匹配，检索下一个短目录项
+                    else if (js > dest_dentry->name_length ||
+                             tmp_ldEntry->LDIR_Name1[x] !=
+                                 (uint16_t)(dest_dentry->name[js++])) // 文件名不匹配，检索下一个短目录项
                         goto continue_cmp_fail;
                 }
 
@@ -113,7 +115,9 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
                 {
                     if (js > dest_dentry->name_length && tmp_ldEntry->LDIR_Name2[x] == 0xffff)
                         continue;
-                    else if (js > dest_dentry->name_length || tmp_ldEntry->LDIR_Name2[x] != (uint16_t)(dest_dentry->name[js++])) // 文件名不匹配，检索下一个短目录项
+                    else if (js > dest_dentry->name_length ||
+                             tmp_ldEntry->LDIR_Name2[x] !=
+                                 (uint16_t)(dest_dentry->name[js++])) // 文件名不匹配，检索下一个短目录项
                         goto continue_cmp_fail;
                 }
 
@@ -122,7 +126,9 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
                 {
                     if (js > dest_dentry->name_length && tmp_ldEntry->LDIR_Name3[x] == 0xffff)
                         continue;
-                    else if (js > dest_dentry->name_length || tmp_ldEntry->LDIR_Name3[x] != (uint16_t)(dest_dentry->name[js++])) // 文件名不匹配，检索下一个短目录项
+                    else if (js > dest_dentry->name_length ||
+                             tmp_ldEntry->LDIR_Name3[x] !=
+                                 (uint16_t)(dest_dentry->name[js++])) // 文件名不匹配，检索下一个短目录项
                         goto continue_cmp_fail;
                 }
 
@@ -159,7 +165,8 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
                     }
                     else // 是文件夹
                     {
-                        if (js < dest_dentry->name_length && tmp_dEntry->DIR_Name[x] == dest_dentry->name[js]) // 当前位正确匹配
+                        if (js < dest_dentry->name_length &&
+                            tmp_dEntry->DIR_Name[x] == dest_dentry->name[js]) // 当前位正确匹配
                         {
                             ++js;
                             break; // 进行下一位的匹配
@@ -284,6 +291,11 @@ struct vfs_dir_entry_t *fat32_lookup(struct vfs_index_node_t *parent_inode, stru
             return NULL;
         }
     }
+    if(unlikely(tmp_dEntry==NULL))
+    {
+        BUG_ON(1);
+        return NULL;
+    }
 find_lookup_success:; // 找到目标dentry
     struct vfs_index_node_t *p = vfs_alloc_inode();
 
@@ -360,13 +372,17 @@ struct vfs_superblock_t *fat32_read_superblock(struct block_device *blk)
     fsbi->fsinfo_sector_addr_infat = fbs->BPB_FSInfo;
     fsbi->bootsector_bak_sector_addr_infat = fbs->BPB_BkBootSec;
 
-    printk_color(ORANGE, BLACK, "FAT32 Boot Sector\n\tBPB_FSInfo:%#018lx\n\tBPB_BkBootSec:%#018lx\n\tBPB_TotSec32:%#018lx\n", fbs->BPB_FSInfo, fbs->BPB_BkBootSec, fbs->BPB_TotSec32);
+    printk_color(ORANGE, BLACK,
+                 "FAT32 Boot Sector\n\tBPB_FSInfo:%#018lx\n\tBPB_BkBootSec:%#018lx\n\tBPB_TotSec32:%#018lx\n",
+                 fbs->BPB_FSInfo, fbs->BPB_BkBootSec, fbs->BPB_TotSec32);
 
     // fsinfo扇区的信息
     memset(&fsbi->fsinfo, 0, sizeof(struct fat32_FSInfo_t));
-    blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, blk->bd_start_LBA + fsbi->fsinfo_sector_addr_infat, 1, (uint64_t)&fsbi->fsinfo);
+    blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT,
+                                 blk->bd_start_LBA + fsbi->fsinfo_sector_addr_infat, 1, (uint64_t)&fsbi->fsinfo);
 
-    printk_color(BLUE, BLACK, "FAT32 FSInfo\n\tFSI_LeadSig:%#018lx\n\tFSI_StrucSig:%#018lx\n\tFSI_Free_Count:%#018lx\n", fsbi->fsinfo.FSI_LeadSig, fsbi->fsinfo.FSI_StrucSig, fsbi->fsinfo.FSI_Free_Count);
+    printk_color(BLUE, BLACK, "FAT32 FSInfo\n\tFSI_LeadSig:%#018lx\n\tFSI_StrucSig:%#018lx\n\tFSI_Free_Count:%#018lx\n",
+                 fsbi->fsinfo.FSI_LeadSig, fsbi->fsinfo.FSI_StrucSig, fsbi->fsinfo.FSI_Free_Count);
 
     // 初始化超级块的dir entry
     sb_ptr->root = vfs_alloc_dentry(2);
@@ -383,7 +399,8 @@ struct vfs_superblock_t *fat32_read_superblock(struct block_device *blk)
     sb_ptr->root->dir_inode->file_ops = &fat32_file_ops;
     sb_ptr->root->dir_inode->file_size = 0;
     // 计算文件占用的扇区数, 由于最小存储单位是簇，因此需要按照簇的大小来对齐扇区
-    sb_ptr->root->dir_inode->blocks = (sb_ptr->root->dir_inode->file_size + fsbi->bytes_per_clus - 1) / fsbi->bytes_per_sec;
+    sb_ptr->root->dir_inode->blocks =
+        (sb_ptr->root->dir_inode->file_size + fsbi->bytes_per_clus - 1) / fsbi->bytes_per_sec;
     sb_ptr->root->dir_inode->attribute = VFS_IF_DIR;
     sb_ptr->root->dir_inode->sb = sb_ptr; // 反向绑定对应的超级块
 
@@ -449,7 +466,8 @@ void fat32_write_inode(struct vfs_index_node_t *inode)
     struct fat32_Directory_t *buf = (struct fat32_Directory_t *)kmalloc(fsbi->bytes_per_clus, 0);
     memset(buf, 0, fsbi->bytes_per_clus);
 
-    inode->sb->blk_device->bd_disk->fops->transfer(inode->sb->blk_device->bd_disk, AHCI_CMD_READ_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf);
+    inode->sb->blk_device->bd_disk->fops->transfer(inode->sb->blk_device->bd_disk, AHCI_CMD_READ_DMA_EXT, fLBA,
+                                                   fsbi->sec_per_clus, (uint64_t)buf);
     // 计算目标dEntry所在的位置
     struct fat32_Directory_t *fdEntry = buf + finode->dEntry_location_clus_offset;
 
@@ -459,12 +477,12 @@ void fat32_write_inode(struct vfs_index_node_t *inode)
     fdEntry->DIR_FstClusHI = (finode->first_clus >> 16) | (fdEntry->DIR_FstClusHI & 0xf000);
 
     // 将dir entry写回磁盘
-    inode->sb->blk_device->bd_disk->fops->transfer(inode->sb->blk_device->bd_disk, AHCI_CMD_WRITE_DMA_EXT, fLBA, fsbi->sec_per_clus, (uint64_t)buf);
+    inode->sb->blk_device->bd_disk->fops->transfer(inode->sb->blk_device->bd_disk, AHCI_CMD_WRITE_DMA_EXT, fLBA,
+                                                   fsbi->sec_per_clus, (uint64_t)buf);
     kfree(buf);
 }
 
-struct vfs_super_block_operations_t fat32_sb_ops =
+struct vfs_super_block_operations_t fat32_sb_ops = {
-    {
     .write_superblock = fat32_write_superblock,
     .put_superblock = fat32_put_superblock,
     .write_inode = fat32_write_inode,
@@ -473,26 +491,29 @@ struct vfs_super_block_operations_t fat32_sb_ops =
 // todo: compare
 long fat32_compare(struct vfs_dir_entry_t *parent_dEntry, char *source_filename, char *dest_filename)
 {
+    return 0;
 }
 // todo: hash
 long fat32_hash(struct vfs_dir_entry_t *dEntry, char *filename)
 {
+    return 0;
 }
 // todo: release
 long fat32_release(struct vfs_dir_entry_t *dEntry)
 {
+    return 0;
 }
 // todo: iput
 long fat32_iput(struct vfs_dir_entry_t *dEntry, struct vfs_index_node_t *inode)
 {
+    return 0;
 }
 
 /**
  * @brief fat32文件系统对于dEntry的操作
  *
  */
-struct vfs_dir_entry_operations_t fat32_dEntry_ops =
+struct vfs_dir_entry_operations_t fat32_dEntry_ops = {
-    {
     .compare = fat32_compare,
     .hash = fat32_hash,
     .release = fat32_release,
@@ -529,7 +550,8 @@ long fat32_read(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *pos
 
     // First cluster num of the file
     uint64_t cluster = finode->first_clus;
-    // kdebug("fsbi->bytes_per_clus=%d fsbi->sec_per_clus=%d finode->first_clus=%d cluster=%d", fsbi->bytes_per_clus, fsbi->sec_per_clus, finode->first_clus, cluster);
+    // kdebug("fsbi->bytes_per_clus=%d fsbi->sec_per_clus=%d finode->first_clus=%d cluster=%d", fsbi->bytes_per_clus,
+    // fsbi->sec_per_clus, finode->first_clus, cluster);
 
     // kdebug("fsbi->bytes_per_clus=%d", fsbi->bytes_per_clus);
 
@@ -563,7 +585,8 @@ long fat32_read(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *pos
         uint64_t sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
 
         // 读取一个簇的数据
-        int errno = blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buffer);
+        int errno = blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus,
+                                                 (uint64_t)tmp_buffer);
         if (errno != AHCI_SUCCESS)
         {
             kerror("FAT32 FS(read) error!");
@@ -656,7 +679,8 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
         {
             // kdebug("read existed sec=%ld", sector);
             //  读取一个簇的数据
-            int errno = blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buffer);
+            int errno = blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus,
+                                                     (uint64_t)tmp_buffer);
             if (errno != AHCI_SUCCESS)
             {
                 // kerror("FAT32 FS(write)  read disk error!");
@@ -678,7 +702,8 @@ long fat32_write(struct vfs_file_t *file_ptr, char *buf, int64_t count, long *po
             memcpy(tmp_buffer + bytes_offset, buf, step_trans_len);
 
         // 写入数据到对应的簇
-        int errno = blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_WRITE_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)tmp_buffer);
+        int errno = blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_WRITE_DMA_EXT, sector, fsbi->sec_per_clus,
+                                                 (uint64_t)tmp_buffer);
         if (errno != AHCI_SUCCESS)
         {
             kerror("FAT32 FS(write)  write disk error!");
@@ -767,15 +792,14 @@ long fat32_lseek(struct vfs_file_t *file_ptr, long offset, long whence)
 }
 // todo: ioctl
 long fat32_ioctl(struct vfs_index_node_t *inode, struct vfs_file_t *file_ptr, uint64_t cmd, uint64_t arg)
-{
+{return 0;
 }
 
 /**
  * @brief fat32文件系统，关于文件的操作
  *
  */
-struct vfs_file_operations_t fat32_file_ops =
+struct vfs_file_operations_t fat32_file_ops = {
-    {
     .open = fat32_open,
     .close = fat32_close,
     .read = fat32_read,
@@ -836,7 +860,8 @@ long fat32_create(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t
     uint64_t tmp_dentry_clus_buf_addr = 0;
     uint64_t tmp_parent_dentry_clus = 0;
     // 寻找空闲目录项
-    struct fat32_Directory_t *empty_fat32_dentry = fat32_find_empty_dentry(parent_inode, cnt_longname + 1, 0, &tmp_dentry_sector, &tmp_parent_dentry_clus, &tmp_dentry_clus_buf_addr);
+    struct fat32_Directory_t *empty_fat32_dentry = fat32_find_empty_dentry(
+        parent_inode, cnt_longname + 1, 0, &tmp_dentry_sector, &tmp_parent_dentry_clus, &tmp_dentry_clus_buf_addr);
     // kdebug("found empty dentry, cnt_longname=%ld", cnt_longname);
 
     finode->first_clus = 0;
@@ -862,11 +887,13 @@ long fat32_create(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_t
 
     // kdebug("dest_dEntry->name=%s",dest_dEntry->name);
     // ======== 填写长目录项
-    fat32_fill_longname(dest_dEntry, (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1), short_dentry_ChkSum, cnt_longname);
+    fat32_fill_longname(dest_dEntry, (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1), short_dentry_ChkSum,
+                        cnt_longname);
 
     // ====== 将目录项写回磁盘
     // kdebug("tmp_dentry_sector=%ld", tmp_dentry_sector);
-    blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_WRITE_DMA_EXT, tmp_dentry_sector, fsbi->sec_per_clus, tmp_dentry_clus_buf_addr);
+    blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_WRITE_DMA_EXT, tmp_dentry_sector, fsbi->sec_per_clus,
+                                 tmp_dentry_clus_buf_addr);
 
     // 注意：parent字段需要在调用函数的地方进行设置
 
@@ -916,7 +943,8 @@ int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_
     uint64_t tmp_dentry_clus_buf_addr = 0;
     uint64_t tmp_parent_dentry_clus = 0;
     // 寻找空闲目录项
-    struct fat32_Directory_t *empty_fat32_dentry = fat32_find_empty_dentry(parent_inode, cnt_longname + 1, 0, &tmp_dentry_sector, &tmp_parent_dentry_clus, &tmp_dentry_clus_buf_addr);
+    struct fat32_Directory_t *empty_fat32_dentry = fat32_find_empty_dentry(
+        parent_inode, cnt_longname + 1, 0, &tmp_dentry_sector, &tmp_parent_dentry_clus, &tmp_dentry_clus_buf_addr);
 
     // ====== 初始化inode =======
     struct vfs_index_node_t *inode = vfs_alloc_inode();
@@ -963,11 +991,13 @@ int64_t fat32_mkdir(struct vfs_index_node_t *parent_inode, struct vfs_dir_entry_
     uint8_t short_dentry_ChkSum = fat32_ChkSum(empty_fat32_dentry->DIR_Name);
 
     // ======== 填写长目录项
-    fat32_fill_longname(dEntry, (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1), short_dentry_ChkSum, cnt_longname);
+    fat32_fill_longname(dEntry, (struct fat32_LongDirectory_t *)(empty_fat32_dentry - 1), short_dentry_ChkSum,
+                        cnt_longname);
 
     // ====== 将目录项写回磁盘
     // kdebug("tmp_dentry_sector=%ld", tmp_dentry_sector);
-    blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_WRITE_DMA_EXT, tmp_dentry_sector, fsbi->sec_per_clus, tmp_dentry_clus_buf_addr);
+    blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_WRITE_DMA_EXT, tmp_dentry_sector, fsbi->sec_per_clus,
+                                 tmp_dentry_clus_buf_addr);
     // ====== 初始化新的文件夹的目录项 =====
     {
         // kdebug("to create dot and dot dot.");
@@ -1019,21 +1049,26 @@ fail:;
 // todo: rmdir
 int64_t fat32_rmdir(struct vfs_index_node_t *inode, struct vfs_dir_entry_t *dEntry)
 {
+    return 0;
 }
 
 // todo: rename
-int64_t fat32_rename(struct vfs_index_node_t *old_inode, struct vfs_dir_entry_t *old_dEntry, struct vfs_index_node_t *new_inode, struct vfs_dir_entry_t *new_dEntry)
+int64_t fat32_rename(struct vfs_index_node_t *old_inode, struct vfs_dir_entry_t *old_dEntry,
+                     struct vfs_index_node_t *new_inode, struct vfs_dir_entry_t *new_dEntry)
 {
+    return 0;
 }
 
 // todo: getAttr
 int64_t fat32_getAttr(struct vfs_dir_entry_t *dEntry, uint64_t *attr)
 {
+    return 0;
 }
 
 // todo: setAttr
 int64_t fat32_setAttr(struct vfs_dir_entry_t *dEntry, uint64_t *attr)
 {
+    return 0;
 }
 /**
  * @brief 读取文件夹(在指定目录中找出有效目录项)
@@ -1077,7 +1112,8 @@ int64_t fat32_readdir(struct vfs_file_t *file_ptr, void *dirent, vfs_filldir_t f
         uint64_t sector = fsbi->first_data_sector + (cluster - 2) * fsbi->sec_per_clus;
         // 读取文件夹目录项当前位置起始扇区的数据
 
-        if (AHCI_SUCCESS != blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, sector, fsbi->sec_per_clus, (uint64_t)buf))
+        if (AHCI_SUCCESS != blk->bd_disk->fops->transfer(blk->bd_disk, AHCI_CMD_READ_DMA_EXT, sector,
+                                                         fsbi->sec_per_clus, (uint64_t)buf))
         {
             // 读取失败
             kerror("Failed to read the file's first sector.");
@@ -1093,7 +1129,8 @@ int64_t fat32_readdir(struct vfs_file_t *file_ptr, void *dirent, vfs_filldir_t f
 
         name_len = 0;
         // 逐个查找短目录项
-        for (int i = file_ptr->position % fsbi->bytes_per_clus; i < fsbi->bytes_per_clus; i += 32, file_ptr->position += 32, ++dentry)
+        for (int i = file_ptr->position % fsbi->bytes_per_clus; i < fsbi->bytes_per_clus;
+             i += 32, file_ptr->position += 32, ++dentry)
         {
             // 若是长目录项则跳过
             if (dentry->DIR_Attr == ATTR_LONG_NAME)
@@ -1107,11 +1144,13 @@ int64_t fat32_readdir(struct vfs_file_t *file_ptr, void *dirent, vfs_filldir_t f
             long_dentry = (struct fat32_LongDirectory_t *)(dentry - 1);
 
             // 如果长目录项有效，则读取长目录项
-            if (long_dentry->LDIR_Attr == ATTR_LONG_NAME && long_dentry->LDIR_Ord != 0xe5 && long_dentry->LDIR_Ord != 0x00 && long_dentry->LDIR_Ord != 0x05)
+            if (long_dentry->LDIR_Attr == ATTR_LONG_NAME && long_dentry->LDIR_Ord != 0xe5 &&
+                long_dentry->LDIR_Ord != 0x00 && long_dentry->LDIR_Ord != 0x05)
             {
                 int count_long_dentry = 0;
                 // 统计长目录项的个数
-                while (long_dentry->LDIR_Attr == ATTR_LONG_NAME && long_dentry->LDIR_Ord != 0xe5 && long_dentry->LDIR_Ord != 0x00 && long_dentry->LDIR_Ord != 0x05)
+                while (long_dentry->LDIR_Attr == ATTR_LONG_NAME && long_dentry->LDIR_Ord != 0xe5 &&
+                       long_dentry->LDIR_Ord != 0x00 && long_dentry->LDIR_Ord != 0x05)
                 {
                     ++count_long_dentry;
                     if (long_dentry->LDIR_Ord & 0x40) // 最后一个长目录项
@@ -1224,8 +1263,7 @@ find_dir_success:;
     return filler(dirent, 0, dir_name, name_len, dentry_type, 0);
 }
 
-struct vfs_inode_operations_t fat32_inode_ops =
+struct vfs_inode_operations_t fat32_inode_ops = {
-    {
     .create = fat32_create,
     .mkdir = fat32_mkdir,
     .rmdir = fat32_rmdir,
@@ -1236,8 +1274,7 @@ struct vfs_inode_operations_t fat32_inode_ops =
 
 };
 
-struct vfs_filesystem_type_t fat32_fs_type =
+struct vfs_filesystem_type_t fat32_fs_type = {
-    {
     .name = "FAT32",
     .fs_flags = 0,
     .read_superblock = fat32_read_superblock,

kernel/ktest/test-bitree.c

@@ -25,6 +25,7 @@ static int compare(void *a, void *b)
 static int release(void *value)
 {
     // kdebug("release");
+    return 0;
 }
 
 /**

kernel/ktest/test-idr.c

@@ -36,7 +36,7 @@ static long ktest_idr_case0(uint64_t arg0, uint64_t arg1)
     assert(idr_pre_get(&k_idr, 0) == 0);
     assert(k_idr.id_free_cnt == IDR_FREE_MAX);
 
-    for (int i = 1; i < 64; i++)
+    for (uint64_t i = 1; i < 64; i++)
     {
         int id = __lowbit_id(i), chk_id = -1;
         for (int j = 0; j < 64; j++)

kernel/ktest/test-kfifo.c

@@ -146,6 +146,7 @@ static long ktest_kfifo_case0_1(uint64_t arg0, uint64_t arg1)
         kfifo_free_alloc(&fifo);
         assert(fifo.buffer == NULL);
     }
+    return 0;
 }
 
 static ktest_case_table kt_kfifo_func_table[] = {

kernel/lib/libUI/screen_manager.c

@@ -108,7 +108,8 @@ static int __check_ui_param(const char *name, const uint8_t type, const struct s
         return -EINVAL;
     if (ops == NULL)
         return -EINVAL;
-    if (ops->install == NULL || ops->uninstall == NULL || ops->enable == NULL || ops->disable == NULL || ops->change == NULL)
+    if (ops->install == NULL || ops->uninstall == NULL || ops->enable == NULL || ops->disable == NULL ||
+        ops->change == NULL)
         return -EINVAL;
 
     return 0;
@@ -204,6 +205,7 @@ int scm_register(struct scm_ui_framework_t *ui)
  */
 int scm_unregister(struct scm_ui_framework_t *ui)
 {
+    return 0;
 }
 
 /**
@@ -214,6 +216,7 @@ int scm_unregister(struct scm_ui_framework_t *ui)
  */
 int scm_unregister_alloc(struct scm_ui_framework_t *ui)
 {
+    return 0;
 }
 
 /**
@@ -258,14 +261,11 @@ int scm_enable_double_buffer()
 
                 __destroy_buffer(buf);
                 kfree(buf);
-
             }
-
         }
 
     } while (list_next(&ptr->list) != &scm_framework_list); // 枚举链表的每一个ui框架
 
-
     // 设置定时刷新的对象
     video_set_refresh_target(__current_framework->buf);
     // 通知显示驱动，启动双缓冲

kernel/lib/printk.c

@@ -1,12 +1,12 @@
 //
 // Created by longjin on 2022/1/22.
 //
-#include <common/printk.h>
 #include <common/kprint.h>
+#include <common/printk.h>
 
-#include <mm/mm.h>
 #include <common/spinlock.h>
 #include <lib/libUI/textui.h>
+#include <mm/mm.h>
 
 #include <common/math.h>
 #include <common/string.h>
@@ -41,8 +41,6 @@ static int skip_and_atoi(const char **s)
     return ans;
 }
 
-int vsprintf(char *buf, const char *fmt, va_list args)
-{
 /**
  * 将字符串按照fmt和args中的内容进行格式化，然后保存到buf中
  * @param buf 结果缓冲区
@@ -50,8 +48,12 @@ int vsprintf(char *buf, const char *fmt, va_list args)
  * @param args 内容
  * @return 最终字符串的长度
  */
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+    // 当需要输出的字符串的指针为空时，使用该字符填充目标字符串的指针
+    static const char __end_zero_char = '\0';
 
-    char *str, *s;
+    char *str = NULL, *s = NULL;
 
     str = buf;
 
@@ -150,7 +152,7 @@ int vsprintf(char *buf, const char *fmt, va_list args)
                 precision = va_arg(args, int);
                 ++fmt;
             }
-            else if is_digit (*fmt)
+            else if (is_digit(*fmt))
             {
                 precision = skip_and_atoi(&fmt);
             }
@@ -201,7 +203,7 @@ int vsprintf(char *buf, const char *fmt, va_list args)
         case 's':
             s = va_arg(args, char *);
             if (!s)
-                s = '\0';
+                s = &__end_zero_char;
             len = strlen(s);
             if (precision < 0)
             {

kernel/mm/mmio-buddy.c

@@ -39,7 +39,8 @@ static __always_inline void __buddy_add_region_obj(int index, struct __mmio_budd
 static __always_inline struct __mmio_buddy_addr_region *__mmio_buddy_create_region(uint64_t vaddr)
 {
     // 申请内存块的空间
-    struct __mmio_buddy_addr_region *region = (struct __mmio_buddy_addr_region *)kzalloc(sizeof(struct __mmio_buddy_addr_region), 0);
+    struct __mmio_buddy_addr_region *region =
+        (struct __mmio_buddy_addr_region *)kzalloc(sizeof(struct __mmio_buddy_addr_region), 0);
     list_init(&region->list);
     region->vaddr = vaddr;
     return region;
@@ -67,7 +68,8 @@ static __always_inline void __buddy_split(struct __mmio_buddy_addr_region *regio
  * @param exp x、y大小的幂
  * @return int 错误码
  */
-static __always_inline int __buddy_merge_blocks(struct __mmio_buddy_addr_region *x, struct __mmio_buddy_addr_region *y, int exp)
+static __always_inline int __buddy_merge_blocks(struct __mmio_buddy_addr_region *x, struct __mmio_buddy_addr_region *y,
+                                                int exp)
 {
     // 判断这两个是否是一对伙伴
     if (unlikely(x->vaddr != buddy_block_vaddr(y->vaddr, exp))) // 不是一对伙伴
@@ -94,7 +96,8 @@ static __always_inline struct __mmio_buddy_addr_region *__buddy_pop_region(int e
 {
     if (unlikely(list_empty(&__mmio_pool.free_regions[__exp2index(exp)].list_head)))
         return NULL;
-    struct __mmio_buddy_addr_region *r = container_of(list_next(&__mmio_pool.free_regions[__exp2index(exp)].list_head), struct __mmio_buddy_addr_region, list);
+    struct __mmio_buddy_addr_region *r = container_of(list_next(&__mmio_pool.free_regions[__exp2index(exp)].list_head),
+                                                      struct __mmio_buddy_addr_region, list);
     list_del(&r->list);
     // 区域计数减1
     --__mmio_pool.free_regions[__exp2index(exp)].num_free;
@@ -169,15 +172,20 @@ static void __buddy_merge(int exp)
  */
 struct __mmio_buddy_addr_region *mmio_buddy_query_addr_region(int exp)
 {
-    if (exp >= MMIO_BUDDY_MAX_EXP)
+    if (unlikely(exp > MMIO_BUDDY_MAX_EXP || exp < MMIO_BUDDY_MIN_EXP))
+    {
+        BUG_ON(1);
         return NULL;
+    }
+    
     if (!list_empty(&__mmio_pool.free_regions[__exp2index(exp)].list_head))
         goto has_block;
 
     // 若没有符合要求的内存块，则先尝试分裂大的块
-    for (int cur_exp = exp; exp <= MMIO_BUDDY_MAX_EXP; ++cur_exp)
+    for (int cur_exp = exp; cur_exp <= MMIO_BUDDY_MAX_EXP; ++cur_exp)
     {
-        if (unlikely(list_empty(&__mmio_pool.free_regions[__exp2index(cur_exp)].list_head))) // 一直寻找到有空闲空间的链表
+        if (unlikely(
+                list_empty(&__mmio_pool.free_regions[__exp2index(cur_exp)].list_head))) // 一直寻找到有空闲空间的链表
             continue;
 
         // 找到了,逐级向下split

kernel/syscall/syscall.c

@@ -1,14 +1,13 @@
 #include "syscall.h"
-#include <process/process.h>
-#include <exception/gate.h>
-#include <exception/irq.h>
-#include <driver/disk/ahci/ahci.h>
-#include <mm/slab.h>
 #include <common/errno.h>
 #include <common/fcntl.h>
 #include <common/string.h>
-#include <filesystem/fat32/fat32.h>
+#include <driver/disk/ahci/ahci.h>
+#include <exception/gate.h>
+#include <exception/irq.h>
 #include <filesystem/VFS/VFS.h>
+#include <filesystem/fat32/fat32.h>
+#include <mm/slab.h>
 #include <process/process.h>
 #include <time/sleep.h>
 
@@ -85,8 +84,7 @@ void syscall_init()
 long enter_syscall_int(ul syscall_id, ul arg0, ul arg1, ul arg2, ul arg3, ul arg4, ul arg5, ul arg6, ul arg7)
 {
     long err_code;
-    __asm__ __volatile__(
+    __asm__ __volatile__("movq %2, %%r8 \n\t"
-        "movq %2, %%r8 \n\t"
                          "movq %3, %%r9 \n\t"
                          "movq %4, %%r10 \n\t"
                          "movq %5, %%r11 \n\t"
@@ -96,7 +94,8 @@ long enter_syscall_int(ul syscall_id, ul arg0, ul arg1, ul arg2, ul arg3, ul arg
                          "movq %9, %%r15 \n\t"
                          "int $0x80   \n\t"
                          : "=a"(err_code)
-        : "a"(syscall_id), "m"(arg0), "m"(arg1), "m"(arg2), "m"(arg3), "m"(arg4), "m"(arg5), "m"(arg6), "m"(arg7)
+                         : "a"(syscall_id), "m"(arg0), "m"(arg1), "m"(arg2), "m"(arg3), "m"(arg4), "m"(arg5), "m"(arg6),
+                           "m"(arg7)
                          : "memory", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "rcx", "rdx");
 
     return err_code;
@@ -122,8 +121,6 @@ ul sys_put_string(struct pt_regs *regs)
     return 0;
 }
 
-
-
 /**
  * @brief 关闭文件系统调用
  *
@@ -187,7 +184,7 @@ uint64_t sys_read(struct pt_regs *regs)
         return -EINVAL;
 
     struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
-    uint64_t ret;
+    uint64_t ret = 0;
     if (file_ptr->file_ops && file_ptr->file_ops->read)
         ret = file_ptr->file_ops->read(file_ptr, (char *)buf, count, &(file_ptr->position));
 
@@ -226,7 +223,7 @@ uint64_t sys_write(struct pt_regs *regs)
         return -EINVAL;
 
     struct vfs_file_t *file_ptr = current_pcb->fds[fd_num];
-    uint64_t ret;
+    uint64_t ret = 0;
     if (file_ptr->file_ops && file_ptr->file_ops->write)
         ret = file_ptr->file_ops->write(file_ptr, (char *)buf, count, &(file_ptr->position));
 
@@ -287,7 +284,8 @@ uint64_t sys_brk(struct pt_regs *regs)
 {
     uint64_t new_brk = PAGE_2M_ALIGN(regs->r8);
 
-    // kdebug("sys_brk input= %#010lx ,  new_brk= %#010lx bytes current_pcb->mm->brk_start=%#018lx current->end_brk=%#018lx", regs->r8, new_brk, current_pcb->mm->brk_start, current_pcb->mm->brk_end);
+    // kdebug("sys_brk input= %#010lx ,  new_brk= %#010lx bytes current_pcb->mm->brk_start=%#018lx
+    // current->end_brk=%#018lx", regs->r8, new_brk, current_pcb->mm->brk_start, current_pcb->mm->brk_end);
 
     if ((int64_t)regs->r8 == -1)
     {
@@ -586,8 +584,7 @@ void do_syscall_int(struct pt_regs *regs, unsigned long error_code)
     regs->rax = ret; // 返回码
 }
 
-system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] =
+system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] = {
-    {
     [0] = system_call_not_exists,
     [1] = sys_put_string,
     [2] = sys_open,
@@ -612,4 +609,5 @@ system_call_t system_call_table[MAX_SYSTEM_CALL_NUM] =
     [21] = sys_mstat,
     [22] = sys_rmdir,
     [23 ... 254] = system_call_not_exists,
-        [255] = sys_ahci_end_req};
+    [255] = sys_ahci_end_req,
+};

user/apps/shell/cmd.c

@@ -291,6 +291,7 @@ int shell_cmd_pwd(int argc, char **argv)
         printf("%s\n", shell_current_path);
     if (argv != NULL)
         free(argv);
+    return 0;
 }
 
 /**
@@ -327,6 +328,7 @@ int shell_cmd_cat(int argc, char **argv)
     free(buf);
     if (argv != NULL)
         free(argv);
+    return 0;
 }
 
 /**
@@ -359,6 +361,7 @@ int shell_cmd_touch(int argc, char **argv)
     close(fd);
     if (argv != NULL)
         free(argv);
+    return 0;
 }
 
 /**
@@ -369,7 +372,7 @@ int shell_cmd_touch(int argc, char **argv)
  * @return int
  */
 // todo:
-int shell_cmd_rm(int argc, char **argv) {}
+int shell_cmd_rm(int argc, char **argv) {return 0;}
 
 /**
  * @brief 创建文件夹的命令

user/apps/shell/cmd_help.c

@@ -19,6 +19,7 @@ int shell_help(int argc, char **argv)
 
     if (argc > 1)
         free(argv);
+    return 0;
 }
 
 void shell_help_cd()

user/libs/libc/math/pow.c

@@ -1,4 +1,4 @@
-#include "math.h"
+#include <libc/math.h>
 #include <libc/stddef.h>
 
 int64_t pow(int64_t x, int y)

user/libs/libc/math/round.c

@@ -1,5 +1,3 @@
-
-
 #include "libm.h"
 
 #if __FLT_EVAL_METHOD__ == 0 || __FLT_EVAL_METHOD__ == 1

user/libs/libc/printf.c

@@ -1,10 +1,10 @@
 #include "printf.h"
 
-#include <libc/stdio.h>
-#include <libsystem/syscall.h>
-#include <libc/string.h>
 #include <libc/math.h>
+#include <libc/stdio.h>
 #include <libc/stdlib.h>
+#include <libc/string.h>
+#include <libsystem/syscall.h>
 
 static char *write_num(char *str, uint64_t num, int base, int field_width, int precision, int flags);
 static char *write_float_point_num(char *str, double num, int field_width, int precision, int flags);
@@ -62,8 +62,6 @@ int sprintf(char *buf, const char *fmt, ...)
     return count;
 }
 
-int vsprintf(char *buf, const char *fmt, va_list args)
-{
 /**
  * 将字符串按照fmt和args中的内容进行格式化，然后保存到buf中
  * @param buf 结果缓冲区
@@ -71,8 +69,12 @@ int vsprintf(char *buf, const char *fmt, va_list args)
  * @param args 内容
  * @return 最终字符串的长度
  */
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+    // 当需要输出的字符串的指针为空时，使用该字符填充目标字符串的指针
+    static const char __end_zero_char = '\0';
 
-    char *str, *s;
+    char *str = NULL, *s = NULL;
 
     str = buf;
 
@@ -222,7 +224,7 @@ int vsprintf(char *buf, const char *fmt, va_list args)
         case 's':
             s = va_arg(args, char *);
             if (!s)
-                s = '\0';
+                s = &__end_zero_char;
             len = strlen(s);
             if (precision < 0)
             {