Don't read anything from the disk for a segment with p_filesz == 0.

[pintos-anon] / src / userprog / exception.c

diff --git a/src/userprog/exception.c b/src/userprog/exception.c
index 47bfbc278878595b1cf0fa15d73d374057a994d7..19aca125e331783bad87330e8e7213f72072e580 100644 (file)
--- a/src/userprog/exception.c
+++ b/src/userprog/exception.c
@@ -24,8 +24,8 @@ static void page_fault (struct intr_frame *);
    way as other exceptions, but this will need to change to
    implement virtual memory.
 
    way as other exceptions, but this will need to change to
    implement virtual memory.
 

-   Refer to [IA32-v3] section 5.14 for a description of each of
-   these exceptions. */
+   Refer to [IA32-v3a] section 5.15 "Exception and Interrupt
+   Reference" for a description of each of these exceptions. */

 void
 exception_init (void) 
 {
 void
 exception_init (void) 
 {


@@ -114,11 +114,11 @@ kill (struct intr_frame *f)
 
    At entry, the address that faulted is in CR2 (Control Register
    2) and information about the fault, formatted as described in
 
    At entry, the address that faulted is in CR2 (Control Register
    2) and information about the fault, formatted as described in

-   the PF_* macros above, is in F's error_code member.  The
+   the PF_* macros in exception.h, is in F's error_code member.  The

    example code here shows how to parse that information.  You
    can find more information about both of these in the
    description of "Interrupt 14--Page Fault Exception (#PF)" in
    example code here shows how to parse that information.  You
    can find more information about both of these in the
    description of "Interrupt 14--Page Fault Exception (#PF)" in

-   [IA32-v3] section 5.14, which is pages 5-46 to 5-49. */
+   [IA32-v3a] section 5.15 "Exception and Interrupt Reference". */

 static void
 page_fault (struct intr_frame *f) 
 {
 static void
 page_fault (struct intr_frame *f) 
 {


@@ -132,7 +132,7 @@ page_fault (struct intr_frame *f)
      data.  It is not necessarily the address of the instruction
      that caused the fault (that's f->eip).
      See [IA32-v2a] "MOV--Move to/from Control Registers" and
      data.  It is not necessarily the address of the instruction
      that caused the fault (that's f->eip).
      See [IA32-v2a] "MOV--Move to/from Control Registers" and

-     [IA32-v3] 5.14 "Interrupt 14--Page Fault Exception
+     [IA32-v3a] 5.15 "Interrupt 14--Page Fault Exception

      (#PF)". */
   asm ("movl %%cr2, %0" : "=r" (fault_addr));
 
      (#PF)". */
   asm ("movl %%cr2, %0" : "=r" (fault_addr));