brain-hackers_pepepper-mirror/linux-brain
1
0
Fork 0
mirror of https://github.com/brain-hackers/linux-brain.git synced 2024-06-09 15:26:21 +09:00
Code Issues Projects Releases Wiki Activity

compiler-based memory initialization update

Browse Source 
- Update stack auto-initialization selftest for Clang initialization pattern
 -----BEGIN PGP SIGNATURE-----
 Comment: Kees Cook <kees@outflux.net>
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAl0IYMcWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJsgVD/wO3F1KkJ4UtTd81RMlsouBgK/q
 XsYhuQ6YcOvsh41te8SUmY1YS7/SdtmfIjtTlS42pLVcNT+XROVNRSCCnuETd/lW
 Zp6SjfMU3Dd2zn6oVQRAYtO40YAGWqOvFwp4lHNXLo9zObqXOe/JrmPrLpnmEFeX
 7ZQ0yFGWq4No5CKs6M8G/gNKI1z7DOlXtV/jT/otjekqukJnpwDdjBqhkPZpOMuC
 RyHgp9fFvnOBqMgPwUlzwDZLP3zCw/5N01myJZibTFCcFlZGD4IpuBJojrXwm3t4
 +0Qx/Uz52pOTyUKkg26iIDJkX9LqBHxFeuPBVOxWXDW0xoMFqroDa/jWom5uFenK
 wYllZ0ixmlrHNqn1WlQsPjs5Awomh4btJ60D8JK7URhGWt34uzqH651aJaBoa9i3
 jwCpiog4k/4r6nTKCQ5L1FiZoAAbmt2liv2MkQMYTdUoqlg7/gbgA3FPaIPN+969
 WhBY6NqGrDVHyorQdAGw/Hmajj96A+d0pXtZUDZnYUke6IT1iuzr75adyZVNUNav
 0/Rq2wDIa801tA2upe8GwCeYihhUyWnCPbPo+h4YaPQnb9UA9ScWbrR0rihHy1eu
 htmLdDR7/p0p8w1o17dOwm7V9pY/qtxwlKm+VxKNLSfvuMHhVJyLePE9hrgeXXxr
 0Rt//ZrZfPnUIu5tkw==
 =bBoU
 -----END PGP SIGNATURE-----

Merge tag 'meminit-v5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull stack init fix from Kees Cook:
 "This is a small update to the stack auto-initialization self-test code
  to deal with the Clang initialization pattern.

  It's been in linux-next for a couple weeks; I had waited a bit
  wondering if anything more substantial was going to show up, but
  nothing has, so I'm sending this now before it gets too late"

* tag 'meminit-v5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lib/test_stackinit: Handle Clang auto-initialization pattern
This commit is contained in:
Linus Torvalds 2019-06-18 10:42:08 -07:00
commit 915ed9320c
1 changed files with 15 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
lib/test_stackinit.c
View File

@ -12,7 +12,7 @@
/* Exfiltration buffer. */
#define MAX_VAR_SIZE 128
static char check_buf[MAX_VAR_SIZE];
static u8 check_buf[MAX_VAR_SIZE];
/* Character array to trigger stack protector in all functions. */
#define VAR_BUFFER 32
@ -106,9 +106,18 @@ static noinline __init int test_ ## name (void) \
\
/* Fill clone type with zero for per-field init. */ \
memset(&zero, 0x00, sizeof(zero)); \
/* Clear entire check buffer for 0xFF overlap test. */ \
memset(check_buf, 0x00, sizeof(check_buf)); \
/* Fill stack with 0xFF. */ \
ignored = leaf_ ##name((unsigned long)&ignored, 1, \
FETCH_ARG_ ## which(zero)); \
/* Verify all bytes overwritten with 0xFF. */ \
for (sum = 0, i = 0; i < target_size; i++) \
sum += (check_buf[i] != 0xFF); \
if (sum) { \
pr_err(#name ": leaf fill was not 0xFF!?\n"); \
return 1; \
} \
/* Clear entire check buffer for later bit tests. */ \
memset(check_buf, 0x00, sizeof(check_buf)); \
/* Extract stack-defined variable contents. */ \
@ -126,9 +135,9 @@ static noinline __init int test_ ## name (void) \
return 1; \
} \
\
/* Look for any set bits in the check region. */ \
for (i = 0; i < sizeof(check_buf); i++) \
sum += (check_buf[i] != 0); \
/* Look for any bytes still 0xFF in check region. */ \
for (sum = 0, i = 0; i < target_size; i++) \
sum += (check_buf[i] == 0xFF); \
\
if (sum == 0) \
pr_info(#name " ok\n"); \
@ -162,13 +171,13 @@ static noinline __init int leaf_ ## name(unsigned long sp, \
* Keep this buffer around to make sure we've got a \
* stack frame of SOME kind... \
*/ \
memset(buf, (char)(sp && 0xff), sizeof(buf)); \
memset(buf, (char)(sp & 0xff), sizeof(buf)); \
/* Fill variable with 0xFF. */ \
if (fill) { \
fill_start = &var; \
fill_size = sizeof(var); \
memset(fill_start, \
(char)((sp && 0xff) | forced_mask), \
(char)((sp & 0xff) | forced_mask), \
fill_size); \
} \
\