修复检查是否跨越64K内存边界的问题

acevest · Sep 22, 2024 · e2f49a9 · e2f49a9
1 parent fef2233
commit e2f49a9
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Showing 3 changed files with 41 additions and 24 deletions.
diff --git a/drivers/ata.c b/drivers/ata.c
@@ -466,9 +466,15 @@ void ata_dma_read_ext(int drv, uint64_t pos, uint16_t count, void *dest) {
     unsigned long dest_paddr = va2pa(dest);
 
     // 不能跨64K边界
+#if 1
     const uint32_t size = count * SECT_SIZE;
     const uint32_t _64K = 1 << 16;
-    assert(((dest_paddr + size) & _64K) == (dest_paddr & _64K));
+    assert(((dest_paddr & (_64K - 1)) + size) <= _64K);
+#else
+    const uint32_t size = count * SECT_SIZE;
+    const uint32_t _64K = 0xFFFF0000;
+    assert(((dest_paddr + size - (size == 0 ? 0 : 1)) & _64K) == (dest_paddr & _64K));
+#endif
 
     ide_ctrl->prdt[0].phys_addr = dest_paddr;
     ide_ctrl->prdt[0].byte_count = size;

diff --git a/kernel/task_disk.c b/kernel/task_disk.c
@@ -37,9 +37,19 @@ void send_disk_request(disk_request_t *r) {
 
     // 校验buffer是否跨64K
     // 先不处理
-    if (((uint32_t)r->buf & 0xFFFF0000) != (((uint32_t)(r->buf + r->count * 512)) & 0xFFFF0000)) {
+
+#if 1
+    {
+        const uint32_t size = r->count * 512;
+        const uint32_t _64K = 1 << 16;
+        assert(((((uint32_t)r->buf) & (_64K - 1)) + size) <= _64K);
+    }
+#else
+    if (((uint32_t)r->buf & 0xFFFF0000) != (((uint32_t)(r->buf + r->count * 512 - 1)) & 0xFFFF0000)) {
+        printk("dma read addr %08x count %d\n", r->buf, r->count);
         panic("disk DMA read cross 64K");
     }
+#endif
 
     mutex_lock(&drv->ide_pci_controller->request_mutex);
     atomic_inc(&drv->ide_pci_controller->request_cnt);
@@ -98,14 +108,14 @@ void disk_task_entry(void *arg) {
 
         switch (r->command) {
         case DISK_REQ_IDENTIFY:
-            printk("try to read disk drive %u identify", drv_no);
+            printk("try to read disk drive %u identify\n", drv_no);
             assert(r->count == 1);
             ata_read_identify(drv_no, 0);
             break;
         case DISK_REQ_READ:
             assert(r->count > 0);
             assert(r->buf != NULL || r->bb->data != NULL);
-            // printk("DISK READ drv_no %u pos %u count %u\n", drv_no, (uint32_t)pos, r->count);
+            // printk("DISK READ drv_no %u pos %u count %u bb %x\n", drv_no, (uint32_t)pos, r->count, r->bb);
             if (r->bb != 0) {
                 ata_dma_read_ext(drv_no, pos, r->count, r->bb->data);
             } else {

diff --git a/kernel/task_root.c b/kernel/task_root.c
@@ -94,14 +94,15 @@ void verify_hd_data(uint64_t sect_nr, uint16_t *buf, const char *name) {
     }
 }
 
-u16 disk_buf1[256];
-u16 disk_buf2[256];
+// 保存它们不跨64KB
+u16 disk_buf1[256] __attribute__((__aligned__(512)));
+u16 disk_buf2[256] __attribute__((__aligned__(512)));
 
 void taskA_entry() {
     current->priority = 7;
 
     while (1) {
-        sysc_wait(37);
+        sysc_wait(97);
 
         uint64_t sect_nr = get_next_deubug_sect_nr();
         memset(disk_buf1, 0, 512);
@@ -128,23 +129,23 @@ void taskB_entry() {
     current->priority = 13;
 
     while (1) {
-        sysc_wait(73);
-        uint64_t sect_nr = get_next_deubug_sect_nr();
-        memset(disk_buf2, 0, 512);
-        disk_request_t r;
-        r.dev = MAKE_DISK_DEV(2, 0);
-        r.command = DISK_REQ_READ;
-        r.pos = sect_nr;
-        r.count = 1;
-        r.buf = disk_buf2;
-        r.bb = 0;
-
-        send_disk_request(&r);
-        //  verify_hd_data(sect_nr, disk_buf2, current->name);
-
-        for (int i = 0; i < 1; i++) {
-            asm("hlt;");
-        }
+        sysc_wait(7);
+        // uint64_t sect_nr = get_next_deubug_sect_nr();
+        // memset(disk_buf2, 0, 512);
+        // disk_request_t r;
+        // r.dev = MAKE_DISK_DEV(2, 0);
+        // r.command = DISK_REQ_READ;
+        // r.pos = sect_nr;
+        // r.count = 1;
+        // r.buf = disk_buf2;
+        // r.bb = 0;
+
+        // send_disk_request(&r);
+        // //  verify_hd_data(sect_nr, disk_buf2, current->name);
+
+        // for (int i = 0; i < 1; i++) {
+        //     asm("hlt;");
+        // }
     }
 }