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touch sbrk()-allocated memory to make sure it exists

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This commit is contained in:
Robert Morris 2020-08-19 13:10:14 -04:00
parent aefa2697d7
commit 59a9863a17
1 changed files with 14 additions and 2 deletions
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16
user/usertests.c
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@ -2006,6 +2006,12 @@ sbrkmuch(char *s)
printf("%s: sbrk test failed to grow big address space; enough phys mem?\n", s);
exit(1);
}
// touch each page to make sure it exists.
char *eee = sbrk(0);
for(char *pp = a; pp < eee; pp += 4096)
*pp = 1;
lastaddr = (char*) (BIG-1);
*lastaddr = 99;
@ -2087,7 +2093,12 @@ sbrkfail(char *s)
for(i = 0; i < sizeof(pids)/sizeof(pids[0]); i++){
if((pids[i] = fork()) == 0){
// allocate a lot of memory
sbrk(BIG - (uint64)sbrk(0));
char *p0 = sbrk(BIG - (uint64)sbrk(0));
if((uint64)p0 != 0xffffffffffffffffLL){
char *p1 = sbrk(0);
for(char *p2 = p0; p2 < p1; p2 += 4096)
*p2 = 1;
}
write(fds[1], "x", 1);
// sit around until killed
for(;;) sleep(1000);
@ -2469,6 +2480,7 @@ execout(char *s)
uint64 a = (uint64) sbrk(4096);
if(a == 0xffffffffffffffffLL)
break;
*(char*)(a + 4096 - 1) = 1;
}
// free a few pages, in order to let exec() make some
@ -2503,7 +2515,7 @@ countfree()
break;
}
// modify the memory to make sure it's really allocated.
*(char *)(a - 1) = 1;
*(char *)(a + 4096 - 1) = 1;
n += 1;
}
sbrk(-((uint64)sbrk(0) - sz0));