summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Experiment with being more precise setting permissions for user pages.
Growing adds R|W pages (without X). Exec() marks the stack only R|W. Probably could setup permissions for text and data better if we call ld with --no-omagic instead of -N.
-rw-r--r--kernel/defs.h2
-rw-r--r--kernel/exec.c4
-rw-r--r--kernel/proc.c2
-rw-r--r--kernel/vm.c4
4 files changed, 6 insertions, 6 deletions
diff --git a/kernel/defs.h b/kernel/defs.h
index 62b9292..5cf2de2 100644
--- a/kernel/defs.h
+++ b/kernel/defs.h
@@ -160,7 +160,7 @@ void kvmmap(pagetable_t, uint64, uint64, uint64, int);
int mappages(pagetable_t, uint64, uint64, uint64, int);
pagetable_t uvmcreate(void);
void uvmfirst(pagetable_t, uchar *, uint);
-uint64 uvmalloc(pagetable_t, uint64, uint64);
+uint64 uvmalloc(pagetable_t, uint64, uint64, int);
uint64 uvmdealloc(pagetable_t, uint64, uint64);
int uvmcopy(pagetable_t, pagetable_t, uint64);
void uvmfree(pagetable_t, uint64);
diff --git a/kernel/exec.c b/kernel/exec.c
index 09b4bdc..3c468e1 100644
--- a/kernel/exec.c
+++ b/kernel/exec.c
@@ -49,7 +49,7 @@ exec(char *path, char **argv)
if(ph.vaddr + ph.memsz < ph.vaddr)
goto bad;
uint64 sz1;
- if((sz1 = uvmalloc(pagetable, sz, ph.vaddr + ph.memsz)) == 0)
+ if((sz1 = uvmalloc(pagetable, sz, ph.vaddr + ph.memsz, PTE_X|PTE_W)) == 0)
goto bad;
sz = sz1;
if((ph.vaddr % PGSIZE) != 0)
@@ -69,7 +69,7 @@ exec(char *path, char **argv)
// Use the second as the user stack.
sz = PGROUNDUP(sz);
uint64 sz1;
- if((sz1 = uvmalloc(pagetable, sz, sz + 2*PGSIZE)) == 0)
+ if((sz1 = uvmalloc(pagetable, sz, sz + 2*PGSIZE, PTE_W)) == 0)
goto bad;
sz = sz1;
uvmclear(pagetable, sz-2*PGSIZE);
diff --git a/kernel/proc.c b/kernel/proc.c
index 580b3b6..0fa6a2c 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -264,7 +264,7 @@ growproc(int n)
sz = p->sz;
if(n > 0){
- if((sz = uvmalloc(p->pagetable, sz, sz + n)) == 0) {
+ if((sz = uvmalloc(p->pagetable, sz, sz + n, PTE_W)) == 0) {
return -1;
}
} else if(n < 0){
diff --git a/kernel/vm.c b/kernel/vm.c
index 3c6f295..284b72d 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -218,7 +218,7 @@ uvmfirst(pagetable_t pagetable, uchar *src, uint sz)
// Allocate PTEs and physical memory to grow process from oldsz to
// newsz, which need not be page aligned. Returns new size or 0 on error.
uint64
-uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz)
+uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz, int xperm)
{
char *mem;
uint64 a;
@@ -234,7 +234,7 @@ uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz)
return 0;
}
memset(mem, 0, PGSIZE);
- if(mappages(pagetable, a, PGSIZE, (uint64)mem, PTE_W|PTE_X|PTE_R|PTE_U) != 0){
+ if(mappages(pagetable, a, PGSIZE, (uint64)mem, PTE_R|PTE_U|xperm) != 0){
kfree(mem);
uvmdealloc(pagetable, a, oldsz);
return 0;