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authorAustin Clements <[email protected]>2012-02-17 23:20:13 -0500
committerAustin Clements <[email protected]>2012-02-17 23:20:13 -0500
commit9d59eb015141697da616a4b98ac27cf4269cd780 (patch)
tree1fc16f0aff8d60a4cf1b3c29f6b0628d3fd04f16
parent12abb1a56164a0d71fb7a76a465c912409f2f60b (diff)
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Make fetchint and fetchstr use proc instead of taking a struct proc
Previously, these were inconsistent: they used their struct proc argument for bounds checking, but always copied the argument from the current address space (and hence the current process). Drop the struct proc argument and always use the current proc. Suggested by Carmi Merimovich.
-rw-r--r--defs.h4
-rw-r--r--syscall.c18
-rw-r--r--sysfile.c4
3 files changed, 13 insertions, 13 deletions
diff --git a/defs.h b/defs.h
index efbbe3d..7f1e88d 100644
--- a/defs.h
+++ b/defs.h
@@ -142,8 +142,8 @@ char* strncpy(char*, const char*, int);
int argint(int, int*);
int argptr(int, char**, int);
int argstr(int, char**);
-int fetchint(struct proc*, uint, int*);
-int fetchstr(struct proc*, uint, char**);
+int fetchint(uint, int*);
+int fetchstr(uint, char**);
void syscall(void);
// timer.c
diff --git a/syscall.c b/syscall.c
index 0918da7..45f758e 100644
--- a/syscall.c
+++ b/syscall.c
@@ -13,28 +13,28 @@
// library system call function. The saved user %esp points
// to a saved program counter, and then the first argument.
-// Fetch the int at addr from process p.
+// Fetch the int at addr from the current process.
int
-fetchint(struct proc *p, uint addr, int *ip)
+fetchint(uint addr, int *ip)
{
- if(addr >= p->sz || addr+4 > p->sz)
+ if(addr >= proc->sz || addr+4 > proc->sz)
return -1;
*ip = *(int*)(addr);
return 0;
}
-// Fetch the nul-terminated string at addr from process p.
+// Fetch the nul-terminated string at addr from the current process.
// Doesn't actually copy the string - just sets *pp to point at it.
// Returns length of string, not including nul.
int
-fetchstr(struct proc *p, uint addr, char **pp)
+fetchstr(uint addr, char **pp)
{
char *s, *ep;
- if(addr >= p->sz)
+ if(addr >= proc->sz)
return -1;
*pp = (char*)addr;
- ep = (char*)p->sz;
+ ep = (char*)proc->sz;
for(s = *pp; s < ep; s++)
if(*s == 0)
return s - *pp;
@@ -45,7 +45,7 @@ fetchstr(struct proc *p, uint addr, char **pp)
int
argint(int n, int *ip)
{
- return fetchint(proc, proc->tf->esp + 4 + 4*n, ip);
+ return fetchint(proc->tf->esp + 4 + 4*n, ip);
}
// Fetch the nth word-sized system call argument as a pointer
@@ -74,7 +74,7 @@ argstr(int n, char **pp)
int addr;
if(argint(n, &addr) < 0)
return -1;
- return fetchstr(proc, addr, pp);
+ return fetchstr(addr, pp);
}
extern int sys_chdir(void);
diff --git a/sysfile.c b/sysfile.c
index e6d08e8..64f2b33 100644
--- a/sysfile.c
+++ b/sysfile.c
@@ -388,13 +388,13 @@ sys_exec(void)
for(i=0;; i++){
if(i >= NELEM(argv))
return -1;
- if(fetchint(proc, uargv+4*i, (int*)&uarg) < 0)
+ if(fetchint(uargv+4*i, (int*)&uarg) < 0)
return -1;
if(uarg == 0){
argv[i] = 0;
break;
}
- if(fetchstr(proc, uarg, &argv[i]) < 0)
+ if(fetchstr(uarg, &argv[i]) < 0)
return -1;
}
return exec(path, argv);