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map kernel instructions r/o

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This commit is contained in:
Robert Morris 2010-09-20 06:00:22 -04:00
parent 26d11ee8dc
commit a9183883b8
2 changed files with 35 additions and 2 deletions
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28
usertests.c
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@ -1419,6 +1419,7 @@ validatetest(void)
printf(stdout, "validate ok\n"); printf(stdout, "validate ok\n");
} }
// does unintialized data start out zero?
char uninit[10000]; char uninit[10000];
void void
bsstest(void) bsstest(void)
@ -1434,6 +1435,32 @@ bsstest(void)
printf(stdout, "bss test ok\n"); printf(stdout, "bss test ok\n");
} }
// does exec do something sensible if the arguments
// are larger than a page?
void
bigargtest(void)
{
int pid, ppid;
ppid = getpid();
pid = fork();
if(pid == 0){
char *args[100];
int i;
for(i = 0; i < 99; i++)
args[i] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
args[99] = 0;
printf(stdout, "bigarg test\n");
exec("echo", args);
printf(stdout, "bigarg test ok\n");
exit();
} else if(pid < 0){
printf(stdout, "bigargtest: fork failed\n");
exit();
}
wait();
}
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
@ -1445,6 +1472,7 @@ main(int argc, char *argv[])
} }
close(open("usertests.ran", O_CREATE)); close(open("usertests.ran", O_CREATE));
// bigargtest();
bsstest(); bsstest();
sbrktest(); sbrktest();
validatetest(); validatetest();

9
vm.c
View file

@ -125,6 +125,9 @@ pde_t*
setupkvm(void) setupkvm(void)
{ {
pde_t *pgdir; pde_t *pgdir;
extern char etext[];
char *rwstart = PGROUNDDOWN(etext) - PGSIZE;
uint rwlen = (uint)rwstart - 0x100000;
// Allocate page directory // Allocate page directory
if(!(pgdir = (pde_t *) kalloc())) if(!(pgdir = (pde_t *) kalloc()))
@ -132,8 +135,10 @@ setupkvm(void)
memset(pgdir, 0, PGSIZE); memset(pgdir, 0, PGSIZE);
if(// Map IO space from 640K to 1Mbyte if(// Map IO space from 640K to 1Mbyte
!mappages(pgdir, (void *)USERTOP, 0x60000, USERTOP, PTE_W) || !mappages(pgdir, (void *)USERTOP, 0x60000, USERTOP, PTE_W) ||
// Map kernel and free memory pool // Map kernel instructions
!mappages(pgdir, (void *)0x100000, PHYSTOP-0x100000, 0x100000, PTE_W) || !mappages(pgdir, (void *)0x100000, rwlen, 0x100000, 0) ||
// Map kernel data and free memory pool
!mappages(pgdir, rwstart, PHYSTOP-(uint)rwstart, (uint)rwstart, PTE_W) ||
// Map devices such as ioapic, lapic, ... // Map devices such as ioapic, lapic, ...
!mappages(pgdir, (void *)0xFE000000, 0x2000000, 0xFE000000, PTE_W)) !mappages(pgdir, (void *)0xFE000000, 0x2000000, 0xFE000000, PTE_W))
return 0; return 0;