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-rw-r--r--kernel/cow.c30
-rw-r--r--kernel/defs.h18
-rw-r--r--kernel/e1000.c178
-rw-r--r--kernel/e1000_dev.h125
-rw-r--r--kernel/exec.c4
-rw-r--r--kernel/file.c21
-rw-r--r--kernel/kalloc.c57
-rw-r--r--kernel/memlayout.h17
-rw-r--r--kernel/net.c374
-rw-r--r--kernel/net.h173
-rw-r--r--kernel/pci.c61
-rw-r--r--kernel/plic.c12
-rw-r--r--kernel/printf.c17
-rw-r--r--kernel/proc.c84
-rw-r--r--kernel/proc.h7
-rw-r--r--kernel/riscv.h19
-rw-r--r--kernel/stats.c3
-rw-r--r--kernel/syscall.c72
-rw-r--r--kernel/syscall.h11
-rw-r--r--kernel/sysfile.c26
-rw-r--r--kernel/sysinfo.c24
-rw-r--r--kernel/sysinfo.h4
-rw-r--r--kernel/sysnet.c185
-rw-r--r--kernel/sysproc.c65
-rw-r--r--kernel/trap.c41
-rw-r--r--kernel/vm.c85
26 files changed, 1667 insertions, 46 deletions
diff --git a/kernel/cow.c b/kernel/cow.c
new file mode 100644
index 0000000..b3634fc
--- /dev/null
+++ b/kernel/cow.c
@@ -0,0 +1,30 @@
+// COW pagefault handler
+#include "types.h"
+#include "riscv.h"
+#include "defs.h"
+
+int
+cow_handler(pagetable_t pagetable, uint64 va)
+{
+ // you can't really write to rediculous pointers
+ if(va >= MAXVA || PGROUNDDOWN(va) == 0)
+ return -1;
+ pte_t *pte = walk(pagetable, va, 0);
+ if(pte == 0 || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0)
+ return -1;
+ if(*pte & PTE_C){
+ uint64 pa_orig = PTE2PA(*pte);
+ uint64 pa_new = (uint64)kalloc();
+ if(pa_new == 0){
+ printf("cow pagefault: kalloc failed\n");
+ return -1;
+ }
+ // copy the page and add write permission
+ memmove((void*)pa_new, (void*)pa_orig, PGSIZE);
+ uint64 flags = (PTE_FLAGS(*pte) | PTE_W) & ~PTE_C;
+ *pte = PA2PTE(pa_new) | flags;
+ kfree((void*)pa_orig);
+ } else if ((*pte & PTE_W) == 0)
+ return -1;
+ return 0;
+}
diff --git a/kernel/defs.h b/kernel/defs.h
index 859fc41..541c97e 100644
--- a/kernel/defs.h
+++ b/kernel/defs.h
@@ -16,6 +16,7 @@ struct superblock;
struct mbuf;
struct sock;
#endif
+struct sysinfo;
// bio.c
void binit(void);
@@ -30,6 +31,9 @@ void consoleinit(void);
void consoleintr(int);
void consputc(int);
+// cow.c
+int cow_handler(pagetable_t, uint64);
+
// exec.c
int exec(char*, char**);
@@ -68,9 +72,12 @@ void ramdiskintr(void);
void ramdiskrw(struct buf*);
// kalloc.c
+int refcnt_inc(uint64);
+int refcnt_dec(uint64);
void* kalloc(void);
void kfree(void *);
void kinit(void);
+int get_freemem(void);
// log.c
void initlog(int, struct superblock*);
@@ -88,6 +95,7 @@ int pipewrite(struct pipe*, uint64, int);
void printf(char*, ...);
void panic(char*) __attribute__((noreturn));
void printfinit(void);
+void backtrace(void);
// proc.c
int cpuid(void);
@@ -114,6 +122,8 @@ void yield(void);
int either_copyout(int user_dst, uint64 dst, void *src, uint64 len);
int either_copyin(void *dst, int user_src, uint64 src, uint64 len);
void procdump(void);
+int get_nproc(void);
+int pgaccess(uint64 base, int len, uint64 mask);
// swtch.S
void swtch(struct context*, struct context*);
@@ -125,9 +135,7 @@ void initlock(struct spinlock*, char*);
void release(struct spinlock*);
void push_off(void);
void pop_off(void);
-#if defined(LAB_LOCK) || defined(LAB_NET)
int atomic_read4(int *addr);
-#endif
#ifdef LAB_LOCK
void freelock(struct spinlock*);
#endif
@@ -155,6 +163,9 @@ int fetchstr(uint64, char*, int);
int fetchaddr(uint64, uint64*);
void syscall();
+// sysinfo.c
+int sys_info(uint64);
+
// trap.c
extern uint ticks;
void trapinit(void);
@@ -187,6 +198,7 @@ uint64 walkaddr(pagetable_t, uint64);
int copyout(pagetable_t, uint64, char *, uint64);
int copyin(pagetable_t, char *, uint64, uint64);
int copyinstr(pagetable_t, char *, uint64, uint64);
+void vmprint(pagetable_t);
// plic.c
void plicinit(void);
@@ -210,14 +222,12 @@ int copyin_new(pagetable_t, char *, uint64, uint64);
int copyinstr_new(pagetable_t, char *, uint64, uint64);
#endif
-#ifdef LAB_LOCK
// stats.c
void statsinit(void);
void statsinc(void);
// sprintf.c
int snprintf(char*, int, char*, ...);
-#endif
#ifdef KCSAN
void kcsaninit();
diff --git a/kernel/e1000.c b/kernel/e1000.c
new file mode 100644
index 0000000..c9ba9e2
--- /dev/null
+++ b/kernel/e1000.c
@@ -0,0 +1,178 @@
+#include "types.h"
+#include "param.h"
+#include "memlayout.h"
+#include "riscv.h"
+#include "spinlock.h"
+#include "proc.h"
+#include "defs.h"
+#include "e1000_dev.h"
+#include "net.h"
+
+#define TX_RING_SIZE 16
+static struct tx_desc tx_ring[TX_RING_SIZE] __attribute__((aligned(16)));
+static struct mbuf *tx_mbufs[TX_RING_SIZE];
+
+#define RX_RING_SIZE 16
+static struct rx_desc rx_ring[RX_RING_SIZE] __attribute__((aligned(16)));
+static struct mbuf *rx_mbufs[RX_RING_SIZE];
+
+// remember where the e1000's registers live.
+static volatile uint32 *regs;
+
+struct spinlock e1000_lock;
+
+// called by pci_init().
+// xregs is the memory address at which the
+// e1000's registers are mapped.
+void
+e1000_init(uint32 *xregs)
+{
+ int i;
+
+ initlock(&e1000_lock, "e1000");
+
+ regs = xregs;
+
+ // Reset the device
+ regs[E1000_IMS] = 0; // disable interrupts
+ regs[E1000_CTL] |= E1000_CTL_RST;
+ regs[E1000_IMS] = 0; // redisable interrupts
+ __sync_synchronize();
+
+ // [E1000 14.5] Transmit initialization
+ memset(tx_ring, 0, sizeof(tx_ring));
+ for (i = 0; i < TX_RING_SIZE; i++) {
+ tx_ring[i].status = E1000_TXD_STAT_DD;
+ tx_mbufs[i] = 0;
+ }
+ regs[E1000_TDBAL] = (uint64) tx_ring;
+ if(sizeof(tx_ring) % 128 != 0)
+ panic("e1000");
+ regs[E1000_TDLEN] = sizeof(tx_ring);
+ regs[E1000_TDH] = regs[E1000_TDT] = 0;
+
+ // [E1000 14.4] Receive initialization
+ memset(rx_ring, 0, sizeof(rx_ring));
+ for (i = 0; i < RX_RING_SIZE; i++) {
+ rx_mbufs[i] = mbufalloc(0);
+ if (!rx_mbufs[i])
+ panic("e1000");
+ rx_ring[i].addr = (uint64) rx_mbufs[i]->head;
+ }
+ regs[E1000_RDBAL] = (uint64) rx_ring;
+ if(sizeof(rx_ring) % 128 != 0)
+ panic("e1000");
+ regs[E1000_RDH] = 0;
+ regs[E1000_RDT] = RX_RING_SIZE - 1;
+ regs[E1000_RDLEN] = sizeof(rx_ring);
+
+ // filter by qemu's MAC address, 52:54:00:12:34:56
+ regs[E1000_RA] = 0x12005452;
+ regs[E1000_RA+1] = 0x5634 | (1<<31);
+ // multicast table
+ for (int i = 0; i < 4096/32; i++)
+ regs[E1000_MTA + i] = 0;
+
+ // transmitter control bits.
+ regs[E1000_TCTL] = E1000_TCTL_EN | // enable
+ E1000_TCTL_PSP | // pad short packets
+ (0x10 << E1000_TCTL_CT_SHIFT) | // collision stuff
+ (0x40 << E1000_TCTL_COLD_SHIFT);
+ regs[E1000_TIPG] = 10 | (8<<10) | (6<<20); // inter-pkt gap
+
+ // receiver control bits.
+ regs[E1000_RCTL] = E1000_RCTL_EN | // enable receiver
+ E1000_RCTL_BAM | // enable broadcast
+ E1000_RCTL_SZ_2048 | // 2048-byte rx buffers
+ E1000_RCTL_SECRC; // strip CRC
+
+ // ask e1000 for receive interrupts.
+ regs[E1000_RDTR] = 0; // interrupt after every received packet (no timer)
+ regs[E1000_RADV] = 0; // interrupt after every packet (no timer)
+ regs[E1000_IMS] = (1 << 7); // RXDW -- Receiver Descriptor Write Back
+}
+
+int
+e1000_transmit(struct mbuf *m)
+{
+ // the mbuf contains an ethernet frame; program it into
+ // the TX descriptor ring so that the e1000 sends it. Stash
+ // a pointer so that it can be freed after sending.
+ acquire(&e1000_lock);
+
+ int cur_idx = regs[E1000_TDT];
+
+ // check if the STAT_DD bit is set in current descriptor
+ // if not set, means a previous tx in this descripter is still in flight, return an error.
+ if(!(tx_ring[cur_idx].status | E1000_TXD_STAT_DD)){
+ release(&e1000_lock);
+ return -1;
+ }
+
+ // free previous mbuf and update current descriptor
+ if(tx_mbufs[cur_idx])
+ mbuffree(tx_mbufs[cur_idx]);
+ tx_ring[cur_idx].addr = (uint64)m->head;
+ tx_ring[cur_idx].length = (uint64)m->len;
+ tx_ring[cur_idx].cmd = E1000_TXD_CMD_RS | E1000_TXD_CMD_EOP;
+ // also clear status bits
+ tx_ring[cur_idx].status = 0;
+
+ // stash current mbuf to tx_mbufs (would be freed later)
+ tx_mbufs[cur_idx] = m;
+
+ // update the ring position to point to the next descriptor;
+ regs[E1000_TDT] = (cur_idx + 1) % TX_RING_SIZE;
+
+ release(&e1000_lock);
+ return 0;
+}
+
+static void
+e1000_recv(void)
+{
+ // Check for packets that have arrived from the e1000
+ // Create and deliver an mbuf for each packet (using net_rx()).
+ while(1){
+ acquire(&e1000_lock);
+ int cur_idx = (regs[E1000_RDT]+1) % RX_RING_SIZE;
+
+ // check if last rx is completed. If not, skip passing to net_rx()
+ if(!(rx_ring[cur_idx].status | E1000_RXD_STAT_DD))
+ break;
+
+ // update the mbuf's length to the len reported by rx_desc
+ // mbufput(rx_mbufs[cur_idx], rx_ring[cur_idx].length);
+ rx_mbufs[cur_idx]->len = rx_ring[cur_idx].length;
+
+ // stash mbuf, for later net_rx()
+ struct mbuf *rx_buf = rx_mbufs[cur_idx];
+
+ // net_rx() would free the passed mbuf invisibly, so we need to re-alloc it
+ rx_mbufs[cur_idx] = mbufalloc(0);
+ if(!rx_mbufs[cur_idx])
+ panic("e1000_recv: mbufalloc");
+
+ // update buffer addr and clear status bits
+ rx_ring[cur_idx].addr = (uint64)rx_mbufs[cur_idx]->head;
+ rx_ring[cur_idx].status = 0;
+
+ // update the E1000_RDT register to point to next position
+ regs[E1000_RDT] = cur_idx;
+ release(&e1000_lock);
+
+ // pass to the network stack, must not hold the lock coz it can lead to deadlocks under different cpus
+ net_rx(rx_buf);
+ }
+}
+
+void
+e1000_intr(void)
+{
+ // tell the e1000 we've seen this interrupt;
+ // without this the e1000 won't raise any
+ // further interrupts.
+ regs[E1000_ICR] = 0xffffffff;
+
+ e1000_recv();
+}
diff --git a/kernel/e1000_dev.h b/kernel/e1000_dev.h
new file mode 100644
index 0000000..9b462df
--- /dev/null
+++ b/kernel/e1000_dev.h
@@ -0,0 +1,125 @@
+//
+// E1000 hardware definitions: registers and DMA ring format.
+// from the Intel 82540EP/EM &c manual.
+//
+
+/* Registers */
+#define E1000_CTL (0x00000/4) /* Device Control Register - RW */
+#define E1000_ICR (0x000C0/4) /* Interrupt Cause Read - R */
+#define E1000_IMS (0x000D0/4) /* Interrupt Mask Set - RW */
+#define E1000_RCTL (0x00100/4) /* RX Control - RW */
+#define E1000_TCTL (0x00400/4) /* TX Control - RW */
+#define E1000_TIPG (0x00410/4) /* TX Inter-packet gap -RW */
+#define E1000_RDBAL (0x02800/4) /* RX Descriptor Base Address Low - RW */
+#define E1000_RDTR (0x02820/4) /* RX Delay Timer */
+#define E1000_RADV (0x0282C/4) /* RX Interrupt Absolute Delay Timer */
+#define E1000_RDH (0x02810/4) /* RX Descriptor Head - RW */
+#define E1000_RDT (0x02818/4) /* RX Descriptor Tail - RW */
+#define E1000_RDLEN (0x02808/4) /* RX Descriptor Length - RW */
+#define E1000_RSRPD (0x02C00/4) /* RX Small Packet Detect Interrupt */
+#define E1000_TDBAL (0x03800/4) /* TX Descriptor Base Address Low - RW */
+#define E1000_TDLEN (0x03808/4) /* TX Descriptor Length - RW */
+#define E1000_TDH (0x03810/4) /* TX Descriptor Head - RW */
+#define E1000_TDT (0x03818/4) /* TX Descripotr Tail - RW */
+#define E1000_MTA (0x05200/4) /* Multicast Table Array - RW Array */
+#define E1000_RA (0x05400/4) /* Receive Address - RW Array */
+
+/* Device Control */
+#define E1000_CTL_SLU 0x00000040 /* set link up */
+#define E1000_CTL_FRCSPD 0x00000800 /* force speed */
+#define E1000_CTL_FRCDPLX 0x00001000 /* force duplex */
+#define E1000_CTL_RST 0x00400000 /* full reset */
+
+/* Transmit Control */
+#define E1000_TCTL_RST 0x00000001 /* software reset */
+#define E1000_TCTL_EN 0x00000002 /* enable tx */
+#define E1000_TCTL_BCE 0x00000004 /* busy check enable */
+#define E1000_TCTL_PSP 0x00000008 /* pad short packets */
+#define E1000_TCTL_CT 0x00000ff0 /* collision threshold */
+#define E1000_TCTL_CT_SHIFT 4
+#define E1000_TCTL_COLD 0x003ff000 /* collision distance */
+#define E1000_TCTL_COLD_SHIFT 12
+#define E1000_TCTL_SWXOFF 0x00400000 /* SW Xoff transmission */
+#define E1000_TCTL_PBE 0x00800000 /* Packet Burst Enable */
+#define E1000_TCTL_RTLC 0x01000000 /* Re-transmit on late collision */
+#define E1000_TCTL_NRTU 0x02000000 /* No Re-transmit on underrun */
+#define E1000_TCTL_MULR 0x10000000 /* Multiple request support */
+
+/* Receive Control */
+#define E1000_RCTL_RST 0x00000001 /* Software reset */
+#define E1000_RCTL_EN 0x00000002 /* enable */
+#define E1000_RCTL_SBP 0x00000004 /* store bad packet */
+#define E1000_RCTL_UPE 0x00000008 /* unicast promiscuous enable */
+#define E1000_RCTL_MPE 0x00000010 /* multicast promiscuous enab */
+#define E1000_RCTL_LPE 0x00000020 /* long packet enable */
+#define E1000_RCTL_LBM_NO 0x00000000 /* no loopback mode */
+#define E1000_RCTL_LBM_MAC 0x00000040 /* MAC loopback mode */
+#define E1000_RCTL_LBM_SLP 0x00000080 /* serial link loopback mode */
+#define E1000_RCTL_LBM_TCVR 0x000000C0 /* tcvr loopback mode */
+#define E1000_RCTL_DTYP_MASK 0x00000C00 /* Descriptor type mask */
+#define E1000_RCTL_DTYP_PS 0x00000400 /* Packet Split descriptor */
+#define E1000_RCTL_RDMTS_HALF 0x00000000 /* rx desc min threshold size */
+#define E1000_RCTL_RDMTS_QUAT 0x00000100 /* rx desc min threshold size */
+#define E1000_RCTL_RDMTS_EIGTH 0x00000200 /* rx desc min threshold size */
+#define E1000_RCTL_MO_SHIFT 12 /* multicast offset shift */
+#define E1000_RCTL_MO_0 0x00000000 /* multicast offset 11:0 */
+#define E1000_RCTL_MO_1 0x00001000 /* multicast offset 12:1 */
+#define E1000_RCTL_MO_2 0x00002000 /* multicast offset 13:2 */
+#define E1000_RCTL_MO_3 0x00003000 /* multicast offset 15:4 */
+#define E1000_RCTL_MDR 0x00004000 /* multicast desc ring 0 */
+#define E1000_RCTL_BAM 0x00008000 /* broadcast enable */
+/* these buffer sizes are valid if E1000_RCTL_BSEX is 0 */
+#define E1000_RCTL_SZ_2048 0x00000000 /* rx buffer size 2048 */
+#define E1000_RCTL_SZ_1024 0x00010000 /* rx buffer size 1024 */
+#define E1000_RCTL_SZ_512 0x00020000 /* rx buffer size 512 */
+#define E1000_RCTL_SZ_256 0x00030000 /* rx buffer size 256 */
+/* these buffer sizes are valid if E1000_RCTL_BSEX is 1 */
+#define E1000_RCTL_SZ_16384 0x00010000 /* rx buffer size 16384 */
+#define E1000_RCTL_SZ_8192 0x00020000 /* rx buffer size 8192 */
+#define E1000_RCTL_SZ_4096 0x00030000 /* rx buffer size 4096 */
+#define E1000_RCTL_VFE 0x00040000 /* vlan filter enable */
+#define E1000_RCTL_CFIEN 0x00080000 /* canonical form enable */
+#define E1000_RCTL_CFI 0x00100000 /* canonical form indicator */
+#define E1000_RCTL_DPF 0x00400000 /* discard pause frames */
+#define E1000_RCTL_PMCF 0x00800000 /* pass MAC control frames */
+#define E1000_RCTL_BSEX 0x02000000 /* Buffer size extension */
+#define E1000_RCTL_SECRC 0x04000000 /* Strip Ethernet CRC */
+#define E1000_RCTL_FLXBUF_MASK 0x78000000 /* Flexible buffer size */
+#define E1000_RCTL_FLXBUF_SHIFT 27 /* Flexible buffer shift */
+
+#define DATA_MAX 1518
+
+/* Transmit Descriptor command definitions [E1000 3.3.3.1] */
+#define E1000_TXD_CMD_EOP 0x01 /* End of Packet */
+#define E1000_TXD_CMD_RS 0x08 /* Report Status */
+
+/* Transmit Descriptor status definitions [E1000 3.3.3.2] */
+#define E1000_TXD_STAT_DD 0x00000001 /* Descriptor Done */
+
+// [E1000 3.3.3]
+struct tx_desc
+{
+ uint64 addr;
+ uint16 length;
+ uint8 cso;
+ uint8 cmd;
+ uint8 status;
+ uint8 css;
+ uint16 special;
+};
+
+/* Receive Descriptor bit definitions [E1000 3.2.3.1] */
+#define E1000_RXD_STAT_DD 0x01 /* Descriptor Done */
+#define E1000_RXD_STAT_EOP 0x02 /* End of Packet */
+
+// [E1000 3.2.3]
+struct rx_desc
+{
+ uint64 addr; /* Address of the descriptor's data buffer */
+ uint16 length; /* Length of data DMAed into data buffer */
+ uint16 csum; /* Packet checksum */
+ uint8 status; /* Descriptor status */
+ uint8 errors; /* Descriptor Errors */
+ uint16 special;
+};
+
diff --git a/kernel/exec.c b/kernel/exec.c
index e18bbb6..35b35f5 100644
--- a/kernel/exec.c
+++ b/kernel/exec.c
@@ -128,6 +128,10 @@ exec(char *path, char **argv)
p->trapframe->sp = sp; // initial stack pointer
proc_freepagetable(oldpagetable, oldsz);
+ if(p->pid == 1){
+ vmprint(p->pagetable);
+ }
+
return argc; // this ends up in a0, the first argument to main(argc, argv)
bad:
diff --git a/kernel/file.c b/kernel/file.c
index 25fa226..0fba21b 100644
--- a/kernel/file.c
+++ b/kernel/file.c
@@ -80,6 +80,11 @@ fileclose(struct file *f)
iput(ff.ip);
end_op();
}
+#ifdef LAB_NET
+ else if(ff.type == FD_SOCK){
+ sockclose(ff.sock);
+ }
+#endif
}
// Get metadata about file f.
@@ -122,7 +127,13 @@ fileread(struct file *f, uint64 addr, int n)
if((r = readi(f->ip, 1, addr, f->off, n)) > 0)
f->off += r;
iunlock(f->ip);
- } else {
+ }
+#ifdef LAB_NET
+ else if(f->type == FD_SOCK){
+ r = sockread(f->sock, addr, n);
+ }
+#endif
+ else {
panic("fileread");
}
@@ -173,7 +184,13 @@ filewrite(struct file *f, uint64 addr, int n)
i += r;
}
ret = (i == n ? n : -1);
- } else {
+ }
+#ifdef LAB_NET
+ else if(f->type == FD_SOCK){
+ ret = sockwrite(f->sock, addr, n);
+ }
+#endif
+ else {
panic("filewrite");
}
diff --git a/kernel/kalloc.c b/kernel/kalloc.c
index 0699e7e..581f0f6 100644
--- a/kernel/kalloc.c
+++ b/kernel/kalloc.c
@@ -23,10 +23,41 @@ struct {
struct run *freelist;
} kmem;
+int phypg_refcnt[PHYSTOP/PGSIZE];
+
+// Increase the refcnt
+int
+refcnt_inc(uint64 pa)
+{
+ acquire(&kmem.lock);
+ int *prefcnt = &phypg_refcnt[pa/PGSIZE];
+ if(pa > PHYSTOP || *prefcnt < 1)
+ panic("increase refcnt");
+ (*prefcnt)++;
+ release(&kmem.lock);
+ return *prefcnt;
+}
+
+// Decrease the refcnt
+int
+refcnt_dec(uint64 pa)
+{
+ acquire(&kmem.lock);
+ int *prefcnt = &phypg_refcnt[pa/PGSIZE];
+ if(pa > PHYSTOP || *prefcnt < 1)
+ panic("decrease refcnt");
+ (*prefcnt)--;
+ release(&kmem.lock);
+ return *prefcnt;
+}
+
void
kinit()
{
initlock(&kmem.lock, "kmem");
+ // init all refcnt to 1, which would later be freed to 0 by kfree()
+ for(uint64 p = PGROUNDUP((uint64)end); p + PGSIZE <= PHYSTOP; p += PGSIZE)
+ phypg_refcnt[p/PGSIZE] = 1;
freerange(end, (void*)PHYSTOP);
}
@@ -51,6 +82,12 @@ kfree(void *pa)
if(((uint64)pa % PGSIZE) != 0 || (char*)pa < end || (uint64)pa >= PHYSTOP)
panic("kfree");
+ refcnt_dec((uint64)pa);
+
+ if(phypg_refcnt[(uint64)pa/PGSIZE] > 0)
+ // We still have refs to this phy page, do not actually free it
+ return;
+
// Fill with junk to catch dangling refs.
memset(pa, 1, PGSIZE);
@@ -72,11 +109,29 @@ kalloc(void)
acquire(&kmem.lock);
r = kmem.freelist;
- if(r)
+ if(r){
+ if(phypg_refcnt[(uint64)r/PGSIZE])
+ panic("kalloc: invalid refcnt");
+ phypg_refcnt[(uint64)r/PGSIZE] = 1;
kmem.freelist = r->next;
+ }
release(&kmem.lock);
if(r)
memset((char*)r, 5, PGSIZE); // fill with junk
return (void*)r;
}
+
+int
+get_freemem(void)
+{
+ int n;
+ struct run *r;
+
+ acquire(&kmem.lock);
+ for (n = 0, r = kmem.freelist; r; r = r->next)
+ n++;
+ release(&kmem.lock);
+
+ return n * PGSIZE;
+}
diff --git a/kernel/memlayout.h b/kernel/memlayout.h
index cac3cb1..74d2fd4 100644
--- a/kernel/memlayout.h
+++ b/kernel/memlayout.h
@@ -25,6 +25,10 @@
#define VIRTIO0 0x10001000
#define VIRTIO0_IRQ 1
+#ifdef LAB_NET
+#define E1000_IRQ 33
+#endif
+
// core local interruptor (CLINT), which contains the timer.
#define CLINT 0x2000000L
#define CLINT_MTIMECMP(hartid) (CLINT + 0x4000 + 8*(hartid))
@@ -34,8 +38,11 @@
#define PLIC 0x0c000000L
#define PLIC_PRIORITY (PLIC + 0x0)
#define PLIC_PENDING (PLIC + 0x1000)
+#define PLIC_MENABLE(hart) (PLIC + 0x2000 + (hart)*0x100)
#define PLIC_SENABLE(hart) (PLIC + 0x2080 + (hart)*0x100)
+#define PLIC_MPRIORITY(hart) (PLIC + 0x200000 + (hart)*0x2000)
#define PLIC_SPRIORITY(hart) (PLIC + 0x201000 + (hart)*0x2000)
+#define PLIC_MCLAIM(hart) (PLIC + 0x200004 + (hart)*0x2000)
#define PLIC_SCLAIM(hart) (PLIC + 0x201004 + (hart)*0x2000)
// the kernel expects there to be RAM
@@ -50,7 +57,7 @@
// map kernel stacks beneath the trampoline,
// each surrounded by invalid guard pages.
-#define KSTACK(p) (TRAMPOLINE - ((p)+1)* 2*PGSIZE)
+#define KSTACK(p) (TRAMPOLINE - (p)*2*PGSIZE - 3*PGSIZE)
// User memory layout.
// Address zero first:
@@ -59,6 +66,14 @@
// fixed-size stack
// expandable heap
// ...
+// USYSCALL (shared with kernel)
// TRAPFRAME (p->trapframe, used by the trampoline)
// TRAMPOLINE (the same page as in the kernel)
#define TRAPFRAME (TRAMPOLINE - PGSIZE)
+#ifdef LAB_PGTBL
+#define USYSCALL (TRAPFRAME - PGSIZE)
+
+struct usyscall {
+ int pid; // Process ID
+};
+#endif
diff --git a/kernel/net.c b/kernel/net.c
new file mode 100644
index 0000000..137ea2b
--- /dev/null
+++ b/kernel/net.c
@@ -0,0 +1,374 @@
+//
+// networking protocol support (IP, UDP, ARP, etc.).
+//
+
+#include "types.h"
+#include "param.h"
+#include "memlayout.h"
+#include "riscv.h"
+#include "spinlock.h"
+#include "proc.h"
+#include "net.h"
+#include "defs.h"
+
+static uint32 local_ip = MAKE_IP_ADDR(10, 0, 2, 15); // qemu's idea of the guest IP
+static uint8 local_mac[ETHADDR_LEN] = { 0x52, 0x54, 0x00, 0x12, 0x34, 0x56 };
+static uint8 broadcast_mac[ETHADDR_LEN] = { 0xFF, 0XFF, 0XFF, 0XFF, 0XFF, 0XFF };
+
+// Strips data from the start of the buffer and returns a pointer to it.
+// Returns 0 if less than the full requested length is available.
+char *
+mbufpull(struct mbuf *m, unsigned int len)
+{
+ char *tmp = m->head;
+ if (m->len < len)
+ return 0;
+ m->len -= len;
+ m->head += len;
+ return tmp;
+}
+
+// Prepends data to the beginning of the buffer and returns a pointer to it.
+char *
+mbufpush(struct mbuf *m, unsigned int len)
+{
+ m->head -= len;
+ if (m->head < m->buf)
+ panic("mbufpush");
+ m->len += len;
+ return m->head;
+}
+
+// Appends data to the end of the buffer and returns a pointer to it.
+char *
+mbufput(struct mbuf *m, unsigned int len)
+{
+ char *tmp = m->head + m->len;
+ m->len += len;
+ if (m->len > MBUF_SIZE)
+ panic("mbufput");
+ return tmp;
+}
+
+// Strips data from the end of the buffer and returns a pointer to it.
+// Returns 0 if less than the full requested length is available.
+char *
+mbuftrim(struct mbuf *m, unsigned int len)
+{
+ if (len > m->len)
+ return 0;
+ m->len -= len;
+ return m->head + m->len;
+}
+
+// Allocates a packet buffer.
+struct mbuf *
+mbufalloc(unsigned int headroom)
+{
+ struct mbuf *m;
+
+ if (headroom > MBUF_SIZE)
+ return 0;
+ m = kalloc();
+ if (m == 0)
+ return 0;
+ m->next = 0;
+ m->head = (char *)m->buf + headroom;
+ m->len = 0;
+ memset(m->buf, 0, sizeof(m->buf));
+ return m;
+}
+
+// Frees a packet buffer.
+void
+mbuffree(struct mbuf *m)
+{
+ kfree(m);
+}
+
+// Pushes an mbuf to the end of the queue.
+void
+mbufq_pushtail(struct mbufq *q, struct mbuf *m)
+{
+ m->next = 0;
+ if (!q->head){
+ q->head = q->tail = m;
+ return;
+ }
+ q->tail->next = m;
+ q->tail = m;
+}
+
+// Pops an mbuf from the start of the queue.
+struct mbuf *
+mbufq_pophead(struct mbufq *q)
+{
+ struct mbuf *head = q->head;
+ if (!head)
+ return 0;
+ q->head = head->next;
+ return head;
+}
+
+// Returns one (nonzero) if the queue is empty.
+int
+mbufq_empty(struct mbufq *q)
+{
+ return q->head == 0;
+}
+
+// Intializes a queue of mbufs.
+void
+mbufq_init(struct mbufq *q)
+{
+ q->head = 0;
+}
+
+// This code is lifted from FreeBSD's ping.c, and is copyright by the Regents
+// of the University of California.
+static unsigned short
+in_cksum(const unsigned char *addr, int len)
+{
+ int nleft = len;
+ const unsigned short *w = (const unsigned short *)addr;
+ unsigned int sum = 0;
+ unsigned short answer = 0;
+
+ /*
+ * Our algorithm is simple, using a 32 bit accumulator (sum), we add
+ * sequential 16 bit words to it, and at the end, fold back all the
+ * carry bits from the top 16 bits into the lower 16 bits.
+ */
+ while (nleft > 1) {
+ sum += *w++;
+ nleft -= 2;
+ }
+
+ /* mop up an odd byte, if necessary */
+ if (nleft == 1) {
+ *(unsigned char *)(&answer) = *(const unsigned char *)w;
+ sum += answer;
+ }
+
+ /* add back carry outs from top 16 bits to low 16 bits */
+ sum = (sum & 0xffff) + (sum >> 16);
+ sum += (sum >> 16);
+ /* guaranteed now that the lower 16 bits of sum are correct */
+
+ answer = ~sum; /* truncate to 16 bits */
+ return answer;
+}
+
+// sends an ethernet packet
+static void
+net_tx_eth(struct mbuf *m, uint16 ethtype)
+{
+ struct eth *ethhdr;
+
+ ethhdr = mbufpushhdr(m, *ethhdr);
+ memmove(ethhdr->shost, local_mac, ETHADDR_LEN);
+ // In a real networking stack, dhost would be set to the address discovered
+ // through ARP. Because we don't support enough of the ARP protocol, set it
+ // to broadcast instead.
+ memmove(ethhdr->dhost, broadcast_mac, ETHADDR_LEN);
+ ethhdr->type = htons(ethtype);
+ if (e1000_transmit(m)) {
+ mbuffree(m);
+ }
+}
+
+// sends an IP packet
+static void
+net_tx_ip(struct mbuf *m, uint8 proto, uint32 dip)
+{
+ struct ip *iphdr;
+
+ // push the IP header
+ iphdr = mbufpushhdr(m, *iphdr);
+ memset(iphdr, 0, sizeof(*iphdr));
+ iphdr->ip_vhl = (4 << 4) | (20 >> 2);
+ iphdr->ip_p = proto;
+ iphdr->ip_src = htonl(local_ip);
+ iphdr->ip_dst = htonl(dip);
+ iphdr->ip_len = htons(m->len);
+ iphdr->ip_ttl = 100;
+ iphdr->ip_sum = in_cksum((unsigned char *)iphdr, sizeof(*iphdr));
+
+ // now on to the ethernet layer
+ net_tx_eth(m, ETHTYPE_IP);
+}
+
+// sends a UDP packet
+void
+net_tx_udp(struct mbuf *m, uint32 dip,
+ uint16 sport, uint16 dport)
+{
+ struct udp *udphdr;
+
+ // put the UDP header
+ udphdr = mbufpushhdr(m, *udphdr);
+ udphdr->sport = htons(sport);
+ udphdr->dport = htons(dport);
+ udphdr->ulen = htons(m->len);
+ udphdr->sum = 0; // zero means no checksum is provided
+
+ // now on to the IP layer
+ net_tx_ip(m, IPPROTO_UDP, dip);
+}
+
+// sends an ARP packet
+static int
+net_tx_arp(uint16 op, uint8 dmac[ETHADDR_LEN], uint32 dip)
+{
+ struct mbuf *m;
+ struct arp *arphdr;
+
+ m = mbufalloc(MBUF_DEFAULT_HEADROOM);
+ if (!m)
+ return -1;
+
+ // generic part of ARP header
+ arphdr = mbufputhdr(m, *arphdr);
+ arphdr->hrd = htons(ARP_HRD_ETHER);
+ arphdr->pro = htons(ETHTYPE_IP);
+ arphdr->hln = ETHADDR_LEN;
+ arphdr->pln = sizeof(uint32);
+ arphdr->op = htons(op);
+
+ // ethernet + IP part of ARP header
+ memmove(arphdr->sha, local_mac, ETHADDR_LEN);
+ arphdr->sip = htonl(local_ip);
+ memmove(arphdr->tha, dmac, ETHADDR_LEN);
+ arphdr->tip = htonl(dip);
+
+ // header is ready, send the packet
+ net_tx_eth(m, ETHTYPE_ARP);
+ return 0;
+}
+
+// receives an ARP packet
+static void
+net_rx_arp(struct mbuf *m)
+{
+ struct arp *arphdr;
+ uint8 smac[ETHADDR_LEN];
+ uint32 sip, tip;
+
+ arphdr = mbufpullhdr(m, *arphdr);
+ if (!arphdr)
+ goto done;
+
+ // validate the ARP header
+ if (ntohs(arphdr->hrd) != ARP_HRD_ETHER ||
+ ntohs(arphdr->pro) != ETHTYPE_IP ||
+ arphdr->hln != ETHADDR_LEN ||
+ arphdr->pln != sizeof(uint32)) {
+ goto done;
+ }
+
+ // only requests are supported so far
+ // check if our IP was solicited
+ tip = ntohl(arphdr->tip); // target IP address
+ if (ntohs(arphdr->op) != ARP_OP_REQUEST || tip != local_ip)
+ goto done;
+
+ // handle the ARP request
+ memmove(smac, arphdr->sha, ETHADDR_LEN); // sender's ethernet address
+ sip = ntohl(arphdr->sip); // sender's IP address (qemu's slirp)
+ net_tx_arp(ARP_OP_REPLY, smac, sip);
+
+done:
+ mbuffree(m);
+}
+
+// receives a UDP packet
+static void
+net_rx_udp(struct mbuf *m, uint16 len, struct ip *iphdr)
+{
+ struct udp *udphdr;
+ uint32 sip;
+ uint16 sport, dport;
+
+
+ udphdr = mbufpullhdr(m, *udphdr);
+ if (!udphdr)
+ goto fail;
+
+ // TODO: validate UDP checksum
+
+ // validate lengths reported in headers
+ if (ntohs(udphdr->ulen) != len)
+ goto fail;
+ len -= sizeof(*udphdr);
+ if (len > m->len)
+ goto fail;
+ // minimum packet size could be larger than the payload
+ mbuftrim(m, m->len - len);
+
+ // parse the necessary fields
+ sip = ntohl(iphdr->ip_src);
+ sport = ntohs(udphdr->sport);
+ dport = ntohs(udphdr->dport);
+ sockrecvudp(m, sip, dport, sport);
+ return;
+
+fail:
+ mbuffree(m);
+}
+
+// receives an IP packet
+static void
+net_rx_ip(struct mbuf *m)
+{
+ struct ip *iphdr;
+ uint16 len;
+
+ iphdr = mbufpullhdr(m, *iphdr);
+ if (!iphdr)
+ goto fail;
+
+ // check IP version and header len
+ if (iphdr->ip_vhl != ((4 << 4) | (20 >> 2)))
+ goto fail;
+ // validate IP checksum
+ if (in_cksum((unsigned char *)iphdr, sizeof(*iphdr)))
+ goto fail;
+ // can't support fragmented IP packets
+ if (htons(iphdr->ip_off) != 0)
+ goto fail;
+ // is the packet addressed to us?
+ if (htonl(iphdr->ip_dst) != local_ip)
+ goto fail;
+ // can only support UDP
+ if (iphdr->ip_p != IPPROTO_UDP)
+ goto fail;
+
+ len = ntohs(iphdr->ip_len) - sizeof(*iphdr);
+ net_rx_udp(m, len, iphdr);
+ return;
+
+fail:
+ mbuffree(m);
+}
+
+// called by e1000 driver's interrupt handler to deliver a packet to the
+// networking stack
+void net_rx(struct mbuf *m)
+{
+ struct eth *ethhdr;
+ uint16 type;
+
+ ethhdr = mbufpullhdr(m, *ethhdr);
+ if (!ethhdr) {
+ mbuffree(m);
+ return;
+ }
+
+ type = ntohs(ethhdr->type);
+ if (type == ETHTYPE_IP)
+ net_rx_ip(m);
+ else if (type == ETHTYPE_ARP)
+ net_rx_arp(m);
+ else
+ mbuffree(m);
+}
diff --git a/kernel/net.h b/kernel/net.h
new file mode 100644
index 0000000..9e6fefe
--- /dev/null
+++ b/kernel/net.h
@@ -0,0 +1,173 @@
+//
+// packet buffer management
+//
+
+#define MBUF_SIZE 2048
+#define MBUF_DEFAULT_HEADROOM 128
+
+struct mbuf {
+ struct mbuf *next; // the next mbuf in the chain
+ char *head; // the current start position of the buffer
+ unsigned int len; // the length of the buffer
+ char buf[MBUF_SIZE]; // the backing store
+};
+
+char *mbufpull(struct mbuf *m, unsigned int len);
+char *mbufpush(struct mbuf *m, unsigned int len);
+char *mbufput(struct mbuf *m, unsigned int len);
+char *mbuftrim(struct mbuf *m, unsigned int len);
+
+// The above functions manipulate the size and position of the buffer:
+// <- push <- trim
+// -> pull -> put
+// [-headroom-][------buffer------][-tailroom-]
+// |----------------MBUF_SIZE-----------------|
+//
+// These marcos automatically typecast and determine the size of header structs.
+// In most situations you should use these instead of the raw ops above.
+#define mbufpullhdr(mbuf, hdr) (typeof(hdr)*)mbufpull(mbuf, sizeof(hdr))
+#define mbufpushhdr(mbuf, hdr) (typeof(hdr)*)mbufpush(mbuf, sizeof(hdr))
+#define mbufputhdr(mbuf, hdr) (typeof(hdr)*)mbufput(mbuf, sizeof(hdr))
+#define mbuftrimhdr(mbuf, hdr) (typeof(hdr)*)mbuftrim(mbuf, sizeof(hdr))
+
+struct mbuf *mbufalloc(unsigned int headroom);
+void mbuffree(struct mbuf *m);
+
+struct mbufq {
+ struct mbuf *head; // the first element in the queue
+ struct mbuf *tail; // the last element in the queue
+};
+
+void mbufq_pushtail(struct mbufq *q, struct mbuf *m);
+struct mbuf *mbufq_pophead(struct mbufq *q);
+int mbufq_empty(struct mbufq *q);
+void mbufq_init(struct mbufq *q);
+
+
+//
+// endianness support
+//
+
+static inline uint16 bswaps(uint16 val)
+{
+ return (((val & 0x00ffU) << 8) |
+ ((val & 0xff00U) >> 8));
+}
+
+static inline uint32 bswapl(uint32 val)
+{
+ return (((val & 0x000000ffUL) << 24) |
+ ((val & 0x0000ff00UL) << 8) |
+ ((val & 0x00ff0000UL) >> 8) |
+ ((val & 0xff000000UL) >> 24));
+}
+
+// Use these macros to convert network bytes to the native byte order.
+// Note that Risc-V uses little endian while network order is big endian.
+#define ntohs bswaps
+#define ntohl bswapl
+#define htons bswaps
+#define htonl bswapl
+
+
+//
+// useful networking headers
+//
+
+#define ETHADDR_LEN 6
+
+// an Ethernet packet header (start of the packet).
+struct eth {
+ uint8 dhost[ETHADDR_LEN];
+ uint8 shost[ETHADDR_LEN];
+ uint16 type;
+} __attribute__((packed));
+
+#define ETHTYPE_IP 0x0800 // Internet protocol
+#define ETHTYPE_ARP 0x0806 // Address resolution protocol
+
+// an IP packet header (comes after an Ethernet header).
+struct ip {
+ uint8 ip_vhl; // version << 4 | header length >> 2
+ uint8 ip_tos; // type of service
+ uint16 ip_len; // total length
+ uint16 ip_id; // identification
+ uint16 ip_off; // fragment offset field
+ uint8 ip_ttl; // time to live
+ uint8 ip_p; // protocol
+ uint16 ip_sum; // checksum
+ uint32 ip_src, ip_dst;
+};
+
+#define IPPROTO_ICMP 1 // Control message protocol
+#define IPPROTO_TCP 6 // Transmission control protocol
+#define IPPROTO_UDP 17 // User datagram protocol
+
+#define MAKE_IP_ADDR(a, b, c, d) \
+ (((uint32)a << 24) | ((uint32)b << 16) | \
+ ((uint32)c << 8) | (uint32)d)
+
+// a UDP packet header (comes after an IP header).
+struct udp {
+ uint16 sport; // source port
+ uint16 dport; // destination port
+ uint16 ulen; // length, including udp header, not including IP header
+ uint16 sum; // checksum
+};
+
+// an ARP packet (comes after an Ethernet header).
+struct arp {
+ uint16 hrd; // format of hardware address
+ uint16 pro; // format of protocol address
+ uint8 hln; // length of hardware address
+ uint8 pln; // length of protocol address
+ uint16 op; // operation
+
+ char sha[ETHADDR_LEN]; // sender hardware address
+ uint32 sip; // sender IP address
+ char tha[ETHADDR_LEN]; // target hardware address
+ uint32 tip; // target IP address
+} __attribute__((packed));
+
+#define ARP_HRD_ETHER 1 // Ethernet
+
+enum {
+ ARP_OP_REQUEST = 1, // requests hw addr given protocol addr
+ ARP_OP_REPLY = 2, // replies a hw addr given protocol addr
+};
+
+// an DNS packet (comes after an UDP header).
+struct dns {
+ uint16 id; // request ID
+
+ uint8 rd: 1; // recursion desired
+ uint8 tc: 1; // truncated
+ uint8 aa: 1; // authoritive
+ uint8 opcode: 4;
+ uint8 qr: 1; // query/response
+ uint8 rcode: 4; // response code
+ uint8 cd: 1; // checking disabled
+ uint8 ad: 1; // authenticated data
+ uint8 z: 1;
+ uint8 ra: 1; // recursion available
+
+ uint16 qdcount; // number of question entries
+ uint16 ancount; // number of resource records in answer section
+ uint16 nscount; // number of NS resource records in authority section
+ uint16 arcount; // number of resource records in additional records
+} __attribute__((packed));
+
+struct dns_question {
+ uint16 qtype;
+ uint16 qclass;
+} __attribute__((packed));
+
+#define ARECORD (0x0001)
+#define QCLASS (0x0001)
+
+struct dns_data {
+ uint16 type;
+ uint16 class;
+ uint32 ttl;
+ uint16 len;
+} __attribute__((packed));
diff --git a/kernel/pci.c b/kernel/pci.c
new file mode 100644
index 0000000..3e361c5
--- /dev/null
+++ b/kernel/pci.c
@@ -0,0 +1,61 @@
+//
+// simple PCI-Express initialization, only
+// works for qemu and its e1000 card.
+//
+
+#include "types.h"
+#include "param.h"
+#include "memlayout.h"
+#include "riscv.h"
+#include "spinlock.h"
+#include "proc.h"
+#include "defs.h"
+
+void
+pci_init()
+{
+ // we'll place the e1000 registers at this address.
+ // vm.c maps this range.
+ uint64 e1000_regs = 0x40000000L;
+
+ // qemu -machine virt puts PCIe config space here.
+ // vm.c maps this range.
+ uint32 *ecam = (uint32 *) 0x30000000L;
+
+ // look at each possible PCI device on bus 0.
+ for(int dev = 0; dev < 32; dev++){
+ int bus = 0;
+ int func = 0;
+ int offset = 0;
+ uint32 off = (bus << 16) | (dev << 11) | (func << 8) | (offset);
+ volatile uint32 *base = ecam + off;
+ uint32 id = base[0];
+
+ // 100e:8086 is an e1000
+ if(id == 0x100e8086){
+ // command and status register.
+ // bit 0 : I/O access enable
+ // bit 1 : memory access enable
+ // bit 2 : enable mastering
+ base[1] = 0b111;
+ __sync_synchronize();
+
+ for(int i = 0; i < 6; i++){
+ uint32 old = base[4+i];
+
+ // writing all 1's to the BAR causes it to be
+ // replaced with its size.
+ base[4+i] = 0xffffffff;
+ __sync_synchronize();
+
+ base[4+i] = old;
+ }
+
+ // tell the e1000 to reveal its registers at
+ // physical address 0x40000000.
+ base[4+0] = e1000_regs;
+
+ e1000_init((uint32*)e1000_regs);
+ }
+ }
+}
diff --git a/kernel/plic.c b/kernel/plic.c
index 4175db9..5c9d96a 100644
--- a/kernel/plic.c
+++ b/kernel/plic.c
@@ -14,6 +14,13 @@ plicinit(void)
// set desired IRQ priorities non-zero (otherwise disabled).
*(uint32*)(PLIC + UART0_IRQ*4) = 1;
*(uint32*)(PLIC + VIRTIO0_IRQ*4) = 1;
+
+#ifdef LAB_NET
+ // PCIE IRQs are 32 to 35
+ for(int irq = 1; irq < 0x35; irq++){
+ *(uint32*)(PLIC + irq*4) = 1;
+ }
+#endif
}
void
@@ -25,6 +32,11 @@ plicinithart(void)
// for the uart and virtio disk.
*(uint32*)PLIC_SENABLE(hart) = (1 << UART0_IRQ) | (1 << VIRTIO0_IRQ);
+#ifdef LAB_NET
+ // hack to get at next 32 IRQs for e1000
+ *(uint32*)(PLIC_SENABLE(hart)+4) = 0xffffffff;
+#endif
+
// set this hart's S-mode priority threshold to 0.
*(uint32*)PLIC_SPRIORITY(hart) = 0;
}
diff --git a/kernel/printf.c b/kernel/printf.c
index 1a50203..509c1c5 100644
--- a/kernel/printf.c
+++ b/kernel/printf.c
@@ -122,6 +122,8 @@ panic(char *s)
printf("panic: ");
printf(s);
printf("\n");
+ backtrace();
+
panicked = 1; // freeze uart output from other CPUs
for(;;)
;
@@ -133,3 +135,18 @@ printfinit(void)
initlock(&pr.lock, "pr");
pr.locking = 1;
}
+
+void
+backtrace(void)
+{
+ uint64 fp = r_fp();
+ printf("backtrace:\n");
+ uint64 stackpg = PGROUNDDOWN(fp);
+ // Whereever fp points to should always live in the stack page
+ while(PGROUNDDOWN(fp) == stackpg){
+ // print the return addr (stored in fp-8)
+ printf("%p\n", *(uint64 *)(fp-8));
+ // load previous (upper stack) fp
+ fp = *(uint64 *)(fp-16);
+ }
+}
diff --git a/kernel/proc.c b/kernel/proc.c
index 58a8a0b..9a9bae9 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -39,6 +39,7 @@ proc_mapstacks(pagetable_t kpgtbl)
if(pa == 0)
panic("kalloc");
uint64 va = KSTACK((int) (p - proc));
+ p->alarm_tickspassed = 0;
kvmmap(kpgtbl, va, (uint64)pa, PGSIZE, PTE_R | PTE_W);
}
}
@@ -132,6 +133,25 @@ found:
return 0;
}
+ // Allocate a usyscall page and fill pid.
+ if((p->usyscall = (struct usyscall *)kalloc()) == 0){
+ freeproc(p);
+ release(&p->lock);
+ return 0;
+ }
+ p->usyscall->pid = p->pid;
+
+ // reset sigalarm props
+ p->alarm_interval = 0;
+ p->alarm_handler = 0;
+ p->alarm_tickspassed = 0;
+ p->alarm_caninvoke = 1;
+ if((p->atpfm = (struct trapframe *)kalloc()) == 0){
+ freeproc(p);
+ release(&p->lock);
+ return 0;
+ }
+
// An empty user page table.
p->pagetable = proc_pagetable(p);
if(p->pagetable == 0){
@@ -158,8 +178,18 @@ freeproc(struct proc *p)
if(p->trapframe)
kfree((void*)p->trapframe);
p->trapframe = 0;
+ if(p->usyscall)
+ kfree((void*)p->usyscall);
+ p->usyscall = 0;
if(p->pagetable)
proc_freepagetable(p->pagetable, p->sz);
+ if(p->atpfm)
+ kfree((void*)p->atpfm);
+ p->atpfm = 0;
+ p->alarm_interval = 0;
+ p->alarm_handler = 0;
+ p->alarm_tickspassed = 0;
+ p->alarm_caninvoke = 1;
p->pagetable = 0;
p->sz = 0;
p->pid = 0;
@@ -172,7 +202,7 @@ freeproc(struct proc *p)
}
// Create a user page table for a given process, with no user memory,
-// but with trampoline and trapframe pages.
+// but with trampoline, trapframe and usyscall pages.
pagetable_t
proc_pagetable(struct proc *p)
{
@@ -202,6 +232,14 @@ proc_pagetable(struct proc *p)
return 0;
}
+ // map the usyscall page below the trapframe page, for
+ // ugetpid().
+ if(mappages(pagetable, USYSCALL, PGSIZE,
+ (uint64)(p->usyscall), PTE_R | PTE_U) < 0){
+ uvmunmap(pagetable, USYSCALL, 1, 0);
+ uvmfree(pagetable, 0);
+ return 0;
+ }
return pagetable;
}
@@ -212,6 +250,7 @@ proc_freepagetable(pagetable_t pagetable, uint64 sz)
{
uvmunmap(pagetable, TRAMPOLINE, 1, 0);
uvmunmap(pagetable, TRAPFRAME, 1, 0);
+ uvmunmap(pagetable, USYSCALL, 1, 0);
uvmfree(pagetable, sz);
}
@@ -299,6 +338,9 @@ fork(void)
// copy saved user registers.
*(np->trapframe) = *(p->trapframe);
+ // inherit trace_mask
+ np->trace_mask = p->trace_mask;
+
// Cause fork to return 0 in the child.
np->trapframe->a0 = 0;
@@ -686,3 +728,43 @@ procdump(void)
printf("\n");
}
}
+
+int
+get_nproc(void)
+{
+ int n = 0;
+ struct proc *p;
+
+ for(int i = 0; i < NPROC; i++) {
+ p = &proc[i];
+ acquire(&p->lock);
+ if(p->state != UNUSED)
+ n++;
+ release(&p->lock);
+ }
+
+ return n;
+}
+
+// lab pagetable: report which pages have been accessed (r/w)
+// according to PTE_A and store it in a bit mask (3rd param)
+int
+pgaccess(uint64 base, int len, uint64 mask_addr)
+{
+ struct proc *p = myproc();
+ pagetable_t pgtbl = p->pagetable;
+ pte_t *pte;
+ int mask = 0;
+
+ // iterater thru pages
+ for(int i = 0; i < len; i++) {
+ pte = walk(pgtbl, base + i * PGSIZE, 0);
+ if(*pte & PTE_A) {
+ *pte &= (~PTE_A); // clear PTE_A to avoid setting it forever
+ mask |= (1L << i);
+ }
+ }
+
+ // now copyout the mask to user memory
+ return copyout(pgtbl, mask_addr, (char *)&mask, sizeof(mask));
+}
diff --git a/kernel/proc.h b/kernel/proc.h
index d021857..a195b02 100644
--- a/kernel/proc.h
+++ b/kernel/proc.h
@@ -91,6 +91,7 @@ struct proc {
int killed; // If non-zero, have been killed
int xstate; // Exit status to be returned to parent's wait
int pid; // Process ID
+ int trace_mask; // SYS_trace mask (1 << SYS_xxx)
// wait_lock must be held when using this:
struct proc *parent; // Parent process
@@ -100,8 +101,14 @@ struct proc {
uint64 sz; // Size of process memory (bytes)
pagetable_t pagetable; // User page table
struct trapframe *trapframe; // data page for trampoline.S
+ struct usyscall *usyscall; // data page for usyscall
struct context context; // swtch() here to run process
struct file *ofile[NOFILE]; // Open files
struct inode *cwd; // Current directory
char name[16]; // Process name (debugging)
+ int alarm_interval; // sigalarm syscall interval
+ uint64 alarm_handler; // sigalarm syscall handler
+ int alarm_tickspassed; // record how many ticks passed since last sigalarm handler call
+ int alarm_caninvoke; // prevent re-entrant calls to handler
+ struct trapframe *atpfm; // trapframe to resume after handling, must hold p->lock
};
diff --git a/kernel/riscv.h b/kernel/riscv.h
index adc3e38..af18972 100644
--- a/kernel/riscv.h
+++ b/kernel/riscv.h
@@ -295,14 +295,6 @@ r_sp()
return x;
}
-static inline uint64
-r_fp()
-{
- uint64 x;
- asm volatile("mv %0, s0" : "=r" (x) );
- return x;
-}
-
// read and write tp, the thread pointer, which xv6 uses to hold
// this core's hartid (core number), the index into cpus[].
static inline uint64
@@ -335,6 +327,15 @@ sfence_vma()
asm volatile("sfence.vma zero, zero");
}
+// read the frame pointer of currently executing func
+static inline uint64
+r_fp()
+{
+ uint64 x;
+ asm volatile("mv %0, s0" : "=r" (x) );
+ return x;
+}
+
typedef uint64 pte_t;
typedef uint64 *pagetable_t; // 512 PTEs
@@ -351,6 +352,8 @@ typedef uint64 *pagetable_t; // 512 PTEs
#define PTE_W (1L << 2)
#define PTE_X (1L << 3)
#define PTE_U (1L << 4) // user can access
+#define PTE_A (1L << 6) // riscv access bit
+#define PTE_C (1L << 8) // RSW low bit, use it to mark whether a page is COW
diff --git a/kernel/stats.c b/kernel/stats.c
index 9659bb9..b7a8e5f 100644
--- a/kernel/stats.c
+++ b/kernel/stats.c
@@ -34,9 +34,6 @@ statsread(int user_dst, uint64 dst, int n)
acquire(&stats.lock);
if(stats.sz == 0) {
-#ifdef LAB_PGTBL
- stats.sz = statscopyin(stats.buf, BUFSZ);
-#endif
#ifdef LAB_LOCK
stats.sz = statslock(stats.buf, BUFSZ);
#endif
diff --git a/kernel/syscall.c b/kernel/syscall.c
index ed65409..172c5ea 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -101,6 +101,24 @@ extern uint64 sys_unlink(void);
extern uint64 sys_link(void);
extern uint64 sys_mkdir(void);
extern uint64 sys_close(void);
+extern uint64 sys_trace(void);
+extern uint64 sys_sysinfo(void);
+
+#ifdef LAB_NET
+extern uint64 sys_connect(void);
+#endif
+#ifdef LAB_PGTBL
+extern uint64 sys_pgaccess(void);
+#endif
+extern uint64 sys_sigalarm(void);
+extern uint64 sys_sigreturn(void);
+
+#ifdef LAB_NET
+extern uint64 sys_connect(void);
+#endif
+#ifdef LAB_PGTBL
+extern uint64 sys_pgaccess(void);
+#endif
// An array mapping syscall numbers from syscall.h
// to the function that handles the system call.
@@ -126,8 +144,54 @@ static uint64 (*syscalls[])(void) = {
[SYS_link] sys_link,
[SYS_mkdir] sys_mkdir,
[SYS_close] sys_close,
+#ifdef LAB_NET
+[SYS_connect] sys_connect,
+#endif
+#ifdef LAB_PGTBL
+[SYS_pgaccess] sys_pgaccess,
+#endif
+[SYS_trace] sys_trace,
+[SYS_sysinfo] sys_sysinfo,
+[SYS_sigalarm] sys_sigalarm,
+[SYS_sigreturn] sys_sigreturn,
+};
+
+// syscall name maps for SYS_trace:
+static char *syscall_names[] = {
+[SYS_fork] "fork",
+[SYS_exit] "exit",
+[SYS_wait] "wait",
+[SYS_pipe] "pipe",
+[SYS_read] "read",
+[SYS_kill] "kill",
+[SYS_exec] "exec",
+[SYS_fstat] "fstat",
+[SYS_chdir] "chdir",
+[SYS_dup] "dup",
+[SYS_getpid] "getpid",
+[SYS_sbrk] "sbrk",
+[SYS_sleep] "sleep",
+[SYS_uptime] "uptime",
+[SYS_open] "open",
+[SYS_write] "write",
+[SYS_mknod] "mknod",
+[SYS_unlink] "unlink",
+[SYS_link] "link",
+[SYS_mkdir] "mkdir",
+[SYS_close] "close",
+#ifdef LAB_NET
+[SYS_connect] "connect",
+#endif
+#ifdef LAB_PGTBL
+[SYS_pgaccess] "pgaccess",
+#endif
+[SYS_trace] "trace",
+[SYS_sysinfo] "sysinfo",
+[SYS_sigalarm] "sigalarm",
+[SYS_sigreturn] "sigreturn",
};
+
void
syscall(void)
{
@@ -139,9 +203,17 @@ syscall(void)
// Use num to lookup the system call function for num, call it,
// and store its return value in p->trapframe->a0
p->trapframe->a0 = syscalls[num]();
+
+ // SYS_trace: match all the syscalls which number < mask asked
+ // p->trace_mask == 1 << SYS_xxx
+ if(p->trace_mask >> num) {
+ printf("%d: syscall %s -> %d\n", p->pid, syscall_names[num], p->trapframe->a0);
+ }
+
} else {
printf("%d %s: unknown sys call %d\n",
p->pid, p->name, num);
p->trapframe->a0 = -1;
}
}
+
diff --git a/kernel/syscall.h b/kernel/syscall.h
index bc5f356..8da572e 100644
--- a/kernel/syscall.h
+++ b/kernel/syscall.h
@@ -20,3 +20,14 @@
#define SYS_link 19
#define SYS_mkdir 20
#define SYS_close 21
+
+// System calls for labs
+#define SYS_trace 22
+#define SYS_sysinfo 23
+#define SYS_sigalarm 24
+#define SYS_sigreturn 25
+#define SYS_symlink 26
+#define SYS_mmap 27
+#define SYS_munmap 28
+#define SYS_connect 29
+#define SYS_pgaccess 30
diff --git a/kernel/sysfile.c b/kernel/sysfile.c
index 16b668c..4b2189a 100644
--- a/kernel/sysfile.c
+++ b/kernel/sysfile.c
@@ -503,3 +503,29 @@ sys_pipe(void)
}
return 0;
}
+
+
+#ifdef LAB_NET
+int
+sys_connect(void)
+{
+ struct file *f;
+ int fd;
+ uint32 raddr;
+ uint32 rport;
+ uint32 lport;
+
+ argint(0, (int*)&raddr);
+ argint(1, (int*)&lport);
+ argint(2, (int*)&rport);
+
+ if(sockalloc(&f, raddr, lport, rport) < 0)
+ return -1;
+ if((fd=fdalloc(f)) < 0){
+ fileclose(f);
+ return -1;
+ }
+
+ return fd;
+}
+#endif
diff --git a/kernel/sysinfo.c b/kernel/sysinfo.c
new file mode 100644
index 0000000..c66324d
--- /dev/null
+++ b/kernel/sysinfo.c
@@ -0,0 +1,24 @@
+#include "types.h"
+#include "riscv.h"
+#include "param.h"
+#include "spinlock.h"
+#include "defs.h"
+#include "sysinfo.h"
+#include "proc.h"
+
+// Get current system info
+// addr is a user virtual address, pointing to a struct sysinfo.
+int
+sys_info(uint64 addr) {
+ struct proc *p = myproc();
+ struct sysinfo info;
+
+ // Fill nums into the sysinfo struct
+ info.freemem = get_freemem();
+ info.nproc = get_nproc();
+
+ if(copyout(p->pagetable, addr, (char *)&info, sizeof(info)) < 0)
+ return -1;
+ return 0;
+}
+
diff --git a/kernel/sysinfo.h b/kernel/sysinfo.h
new file mode 100644
index 0000000..fb878e6
--- /dev/null
+++ b/kernel/sysinfo.h
@@ -0,0 +1,4 @@
+struct sysinfo {
+ uint64 freemem; // amount of free memory (bytes)
+ uint64 nproc; // number of process
+};
diff --git a/kernel/sysnet.c b/kernel/sysnet.c
new file mode 100644
index 0000000..1c48cb3
--- /dev/null
+++ b/kernel/sysnet.c
@@ -0,0 +1,185 @@
+//
+// network system calls.
+//
+
+#include "types.h"
+#include "param.h"
+#include "memlayout.h"
+#include "riscv.h"
+#include "spinlock.h"
+#include "proc.h"
+#include "defs.h"
+#include "fs.h"
+#include "sleeplock.h"
+#include "file.h"
+#include "net.h"
+
+struct sock {
+ struct sock *next; // the next socket in the list
+ uint32 raddr; // the remote IPv4 address
+ uint16 lport; // the local UDP port number
+ uint16 rport; // the remote UDP port number
+ struct spinlock lock; // protects the rxq
+ struct mbufq rxq; // a queue of packets waiting to be received
+};
+
+static struct spinlock lock;
+static struct sock *sockets;
+
+void
+sockinit(void)
+{
+ initlock(&lock, "socktbl");
+}
+
+int
+sockalloc(struct file **f, uint32 raddr, uint16 lport, uint16 rport)
+{
+ struct sock *si, *pos;
+
+ si = 0;
+ *f = 0;
+ if ((*f = filealloc()) == 0)
+ goto bad;
+ if ((si = (struct sock*)kalloc()) == 0)
+ goto bad;
+
+ // initialize objects
+ si->raddr = raddr;
+ si->lport = lport;
+ si->rport = rport;
+ initlock(&si->lock, "sock");
+ mbufq_init(&si->rxq);
+ (*f)->type = FD_SOCK;
+ (*f)->readable = 1;
+ (*f)->writable = 1;
+ (*f)->sock = si;
+
+ // add to list of sockets
+ acquire(&lock);
+ pos = sockets;
+ while (pos) {
+ if (pos->raddr == raddr &&
+ pos->lport == lport &&
+ pos->rport == rport) {
+ release(&lock);
+ goto bad;
+ }
+ pos = pos->next;
+ }
+ si->next = sockets;
+ sockets = si;
+ release(&lock);
+ return 0;
+
+bad:
+ if (si)
+ kfree((char*)si);
+ if (*f)
+ fileclose(*f);
+ return -1;
+}
+
+void
+sockclose(struct sock *si)
+{
+ struct sock **pos;
+ struct mbuf *m;
+
+ // remove from list of sockets
+ acquire(&lock);
+ pos = &sockets;
+ while (*pos) {
+ if (*pos == si){
+ *pos = si->next;
+ break;
+ }
+ pos = &(*pos)->next;
+ }
+ release(&lock);
+
+ // free any pending mbufs
+ while (!mbufq_empty(&si->rxq)) {
+ m = mbufq_pophead(&si->rxq);
+ mbuffree(m);
+ }
+
+ kfree((char*)si);
+}
+
+int
+sockread(struct sock *si, uint64 addr, int n)
+{
+ struct proc *pr = myproc();
+ struct mbuf *m;
+ int len;
+
+ acquire(&si->lock);
+ while (mbufq_empty(&si->rxq) && !pr->killed) {
+ sleep(&si->rxq, &si->lock);
+ }
+ if (pr->killed) {
+ release(&si->lock);
+ return -1;
+ }
+ m = mbufq_pophead(&si->rxq);
+ release(&si->lock);
+
+ len = m->len;
+ if (len > n)
+ len = n;
+ if (copyout(pr->pagetable, addr, m->head, len) == -1) {
+ mbuffree(m);
+ return -1;
+ }
+ mbuffree(m);
+ return len;
+}
+
+int
+sockwrite(struct sock *si, uint64 addr, int n)
+{
+ struct proc *pr = myproc();
+ struct mbuf *m;
+
+ m = mbufalloc(MBUF_DEFAULT_HEADROOM);
+ if (!m)
+ return -1;
+
+ if (copyin(pr->pagetable, mbufput(m, n), addr, n) == -1) {
+ mbuffree(m);
+ return -1;
+ }
+ net_tx_udp(m, si->raddr, si->lport, si->rport);
+ return n;
+}
+
+// called by protocol handler layer to deliver UDP packets
+void
+sockrecvudp(struct mbuf *m, uint32 raddr, uint16 lport, uint16 rport)
+{
+ //
+ // Find the socket that handles this mbuf and deliver it, waking
+ // any sleeping reader. Free the mbuf if there are no sockets
+ // registered to handle it.
+ //
+ struct sock *si;
+
+ acquire(&lock);
+ si = sockets;
+ while (si) {
+ if (si->raddr == raddr && si->lport == lport && si->rport == rport)
+ goto found;
+ si = si->next;
+ }
+ release(&lock);
+ mbuffree(m);
+ return;
+
+found:
+ acquire(&si->lock);
+ mbufq_pushtail(&si->rxq, m);
+ wakeup(&si->rxq);
+ release(&si->lock);
+ release(&lock);
+}
diff --git a/kernel/sysproc.c b/kernel/sysproc.c
index 3b4d5bd..715a511 100644
--- a/kernel/sysproc.c
+++ b/kernel/sysproc.c
@@ -1,7 +1,7 @@
#include "types.h"
#include "riscv.h"
-#include "defs.h"
#include "param.h"
+#include "defs.h"
#include "memlayout.h"
#include "spinlock.h"
#include "proc.h"
@@ -54,9 +54,8 @@ sys_sleep(void)
int n;
uint ticks0;
+
argint(0, &n);
- if(n < 0)
- n = 0;
acquire(&tickslock);
ticks0 = ticks;
while(ticks - ticks0 < n){
@@ -66,10 +65,29 @@ sys_sleep(void)
}
sleep(&ticks, &tickslock);
}
+
+ // backtrace();
+
release(&tickslock);
return 0;
}
+
+#ifdef LAB_PGTBL
+int
+sys_pgaccess(void)
+{
+ uint64 base, mask;
+ int len;
+
+
+ argaddr(0, &base);
+ argint(1, &len);
+ argaddr(2, &mask);
+ return pgaccess(base, len, mask);
+}
+#endif
+
uint64
sys_kill(void)
{
@@ -91,3 +109,44 @@ sys_uptime(void)
release(&tickslock);
return xticks;
}
+
+uint64
+sys_trace(void)
+{
+ argint(0, &myproc()->trace_mask);
+
+ return -(myproc()->trace_mask <= 1);
+}
+
+uint64
+sys_sysinfo(void)
+{
+ uint64 si; // user pointer to struct sysinfo
+
+ argaddr(0, &si);
+ return sys_info(si);
+}
+
+uint64
+sys_sigalarm(void)
+{
+ struct proc *p = myproc();
+ uint64 handler;
+
+ argint(0, &p->alarm_interval);
+ argaddr(1, &handler);
+ p->alarm_handler = handler;
+
+ return 0;
+}
+
+uint64 sys_sigreturn(void)
+{
+ struct proc *p = myproc();
+ // retore saved trapframe to resume
+ memmove(p->trapframe, p->atpfm, sizeof(struct trapframe));
+ p->alarm_tickspassed = 0;
+ p->alarm_caninvoke = 1;
+ // make sure return the original a0 in trapframe to pass test3
+ return p->trapframe->a0;
+}
diff --git a/kernel/trap.c b/kernel/trap.c
index 512c850..7cc69b1 100644
--- a/kernel/trap.c
+++ b/kernel/trap.c
@@ -6,6 +6,12 @@
#include "proc.h"
#include "defs.h"
+/*
+ * Always remember that RISC-V disables interrupts when it starts to take a trap,
+ * so there's no need to call intr_off() at the beginning of trap handling.
+ * Reference: xv6-riscv-book 4.5
+ */
+
struct spinlock tickslock;
uint ticks;
@@ -67,18 +73,41 @@ usertrap(void)
syscall();
} else if((which_dev = devintr()) != 0){
// ok
+ } else if(r_scause() == 13 || r_scause() == 15){
+ // deal with page fault
+ uint64 va = r_stval();
+ if(cow_handler(p->pagetable, va) < 0)
+ goto err;
} else {
+
+
printf("usertrap(): unexpected scause %p pid=%d\n", r_scause(), p->pid);
printf(" sepc=%p stval=%p\n", r_sepc(), r_stval());
+ err:
+ printf("killing the process...\n");
setkilled(p);
}
if(killed(p))
exit(-1);
+
- // give up the CPU if this is a timer interrupt.
- if(which_dev == 2)
+ if(which_dev == 2){
+ // timer interrupt
+ if(p->alarm_interval > 0 && p->alarm_caninvoke){
+ // record sigalarm
+ p->alarm_tickspassed++;
+ if(p->alarm_tickspassed == p->alarm_interval){
+ // store original trapframe in p->atpfm
+ memmove(p->atpfm, p->trapframe, sizeof(struct trapframe));
+ p->alarm_tickspassed = 0;
+ p->alarm_caninvoke = 0;
+ p->trapframe->epc = p->alarm_handler;
+ }
+ }
+ // give up the CPU.
yield();
+ }
usertrapret();
}
@@ -190,7 +219,13 @@ devintr()
uartintr();
} else if(irq == VIRTIO0_IRQ){
virtio_disk_intr();
- } else if(irq){
+ }
+#ifdef LAB_NET
+ else if(irq == E1000_IRQ){
+ e1000_intr();
+ }
+#endif
+ else if(irq){
printf("unexpected interrupt irq=%d\n", irq);
}
diff --git a/kernel/vm.c b/kernel/vm.c
index 5c31e87..be7d042 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -4,6 +4,8 @@
#include "elf.h"
#include "riscv.h"
#include "defs.h"
+#include "spinlock.h"
+#include "proc.h"
#include "fs.h"
/*
@@ -30,6 +32,14 @@ kvmmake(void)
// virtio mmio disk interface
kvmmap(kpgtbl, VIRTIO0, VIRTIO0, PGSIZE, PTE_R | PTE_W);
+#ifdef LAB_NET
+ // PCI-E ECAM (configuration space), for pci.c
+ kvmmap(kpgtbl, 0x30000000L, 0x30000000L, 0x10000000, PTE_R | PTE_W);
+
+ // pci.c maps the e1000's registers here.
+ kvmmap(kpgtbl, 0x40000000L, 0x40000000L, 0x20000, PTE_R | PTE_W);
+#endif
+
// PLIC
kvmmap(kpgtbl, PLIC, PLIC, 0x400000, PTE_R | PTE_W);
@@ -136,9 +146,8 @@ kvmmap(pagetable_t kpgtbl, uint64 va, uint64 pa, uint64 sz, int perm)
}
// Create PTEs for virtual addresses starting at va that refer to
-// physical addresses starting at pa.
-// va and size MUST be page-aligned.
-// Returns 0 on success, -1 if walk() couldn't
+// physical addresses starting at pa. va and size might not
+// be page-aligned. Returns 0 on success, -1 if walk() couldn't
// allocate a needed page-table page.
int
mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa, int perm)
@@ -146,17 +155,11 @@ mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa, int perm)
uint64 a, last;
pte_t *pte;
- if((va % PGSIZE) != 0)
- panic("mappages: va not aligned");
-
- if((size % PGSIZE) != 0)
- panic("mappages: size not aligned");
-
if(size == 0)
panic("mappages: size");
- a = va;
- last = va + size - PGSIZE;
+ a = PGROUNDDOWN(va);
+ last = PGROUNDDOWN(va + size - 1);
for(;;){
if((pte = walk(pagetable, a, 1)) == 0)
return -1;
@@ -186,8 +189,10 @@ uvmunmap(pagetable_t pagetable, uint64 va, uint64 npages, int do_free)
for(a = va; a < va + npages*PGSIZE; a += PGSIZE){
if((pte = walk(pagetable, a, 0)) == 0)
panic("uvmunmap: walk");
- if((*pte & PTE_V) == 0)
+ if((*pte & PTE_V) == 0) {
+ printf("va=%p pte=%p\n", a, *pte);
panic("uvmunmap: not mapped");
+ }
if(PTE_FLAGS(*pte) == PTE_V)
panic("uvmunmap: not a leaf");
if(do_free){
@@ -315,20 +320,26 @@ uvmcopy(pagetable_t old, pagetable_t new, uint64 sz)
pte_t *pte;
uint64 pa, i;
uint flags;
- char *mem;
+ // char *mem;
for(i = 0; i < sz; i += PGSIZE){
if((pte = walk(old, i, 0)) == 0)
panic("uvmcopy: pte should exist");
if((*pte & PTE_V) == 0)
panic("uvmcopy: page not present");
- pa = PTE2PA(*pte);
- flags = PTE_FLAGS(*pte);
+ // do not do the actual copy, just increase the refcnt and mark pages readonly COW
+ /*
if((mem = kalloc()) == 0)
goto err;
memmove(mem, (char*)pa, PGSIZE);
- if(mappages(new, i, PGSIZE, (uint64)mem, flags) != 0){
- kfree(mem);
+ */
+ *pte &= ~PTE_W;
+ *pte |= PTE_C;
+ pa = PTE2PA(*pte);
+ refcnt_inc(pa);
+ flags = PTE_FLAGS(*pte);
+ if(mappages(new, i, PGSIZE, (uint64)pa, flags) != 0){
+ // kfree(mem);
goto err;
}
}
@@ -359,17 +370,24 @@ int
copyout(pagetable_t pagetable, uint64 dstva, char *src, uint64 len)
{
uint64 n, va0, pa0;
- pte_t *pte;
+ // pte_t *pte;
while(len > 0){
va0 = PGROUNDDOWN(dstva);
- if(va0 >= MAXVA)
+
+ if(cow_handler(pagetable, va0) < 0)
return -1;
+
+ /*
pte = walk(pagetable, va0, 0);
if(pte == 0 || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0 ||
(*pte & PTE_W) == 0)
return -1;
pa0 = PTE2PA(*pte);
+ */
+ pa0 = walkaddr(pagetable, va0);
+ if(pa0 == 0)
+ return -1;
n = PGSIZE - (dstva - va0);
if(n > len)
n = len;
@@ -389,7 +407,7 @@ int
copyin(pagetable_t pagetable, char *dst, uint64 srcva, uint64 len)
{
uint64 n, va0, pa0;
-
+
while(len > 0){
va0 = PGROUNDDOWN(srcva);
pa0 = walkaddr(pagetable, va0);
@@ -449,3 +467,30 @@ copyinstr(pagetable_t pagetable, char *dst, uint64 srcva, uint64 max)
return -1;
}
}
+
+static void
+walkprint(pagetable_t pgtbl, int level)
+{
+ for(int i = 0; i < 512; i++){
+ pte_t pte = pgtbl[i];
+ if(pte & PTE_V){
+ for(int j = 0; j < level; j++){
+ printf(" ..");
+ }
+ printf("%d: pte %p pa %p\n", i, pte, PTE2PA(pte));
+ if((pte & (PTE_R|PTE_W|PTE_X)) == 0){
+ // this PTE points to a lower-level page table.
+ walkprint((pagetable_t)PTE2PA(pte), level+1);
+ }
+ }
+ }
+}
+
+// Print the contents of a page table
+void
+vmprint(pagetable_t pgtbl)
+{
+ printf("page table %p\n", pgtbl);
+
+ walkprint(pgtbl, 1);
+}
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