[compiler-rt] r201252 - [sanitizer] Intercept capget()/capset().

[Sergey Matveev]

Author: smatveev
Date: Wed Feb 12 13:29:49 2014
New Revision: 201252

URL: http://llvm.org/viewvc/llvm-project?rev=201252&view=rev
Log:
[sanitizer] Intercept capget()/capset().

Also, fix incorrect syscall hooks for the corresponding syscalls.

Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=201252&r1=201251&r2=201252&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc Wed Feb 12 13:29:49 2014
@@ -3265,6 +3265,36 @@ INTERCEPTOR(unsigned int, if_nametoindex
 #define INIT_IF_INDEXTONAME
 #endif
 
+#if SANITIZER_INTERCEPT_CAPGET
+INTERCEPTOR(int, capget, void *hdrp, void *datap) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, capget, hdrp, datap);
+  if (hdrp)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, hdrp, __user_cap_header_struct_sz);
+  int res = REAL(capget)(hdrp, datap);
+  if (res == 0 && datap)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, datap, __user_cap_data_struct_sz);
+  // We can also return -1 and write to hdrp->version if the version passed in
+  // hdrp->version is unsupported. But that's not a trivial condition to check,
+  // and anyway COMMON_INTERCEPTOR_READ_RANGE protects us to some extent.
+  return res;
+}
+INTERCEPTOR(int, capset, void *hdrp, const void *datap) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, capset, hdrp, datap);
+  if (hdrp)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, hdrp, __user_cap_header_struct_sz);
+  if (datap)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, datap, __user_cap_data_struct_sz);
+  return REAL(capset)(hdrp, datap);
+}
+#define INIT_CAPGET                  \
+  COMMON_INTERCEPT_FUNCTION(capget); \
+  COMMON_INTERCEPT_FUNCTION(capset);
+#else
+#define INIT_CAPGET
+#endif
+
 #define SANITIZER_COMMON_INTERCEPTORS_INIT \
   INIT_TEXTDOMAIN;                         \
   INIT_STRCMP;                             \
@@ -3386,5 +3416,6 @@ INTERCEPTOR(unsigned int, if_nametoindex
   INIT_GETXATTR;                           \
   INIT_GETRESID;                           \
   INIT_GETIFADDRS;                         \
-  INIT_IF_INDEXTONAME;
+  INIT_IF_INDEXTONAME;                     \
+  INIT_CAPGET;
 /**/

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc?rev=201252&r1=201251&r2=201252&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_syscalls.inc Wed Feb 12 13:29:49 2014
@@ -388,24 +388,21 @@ PRE_SYSCALL(acct)(const void *name) {
 
 POST_SYSCALL(acct)(long res, const void *name) {}
 
-PRE_SYSCALL(capget)(void *header, void *dataptr) {}
+PRE_SYSCALL(capget)(void *header, void *dataptr) {
+  if (header) PRE_READ(header, __user_cap_header_struct_sz);
+}
 
 POST_SYSCALL(capget)(long res, void *header, void *dataptr) {
-  if (res >= 0) {
-    if (header) POST_WRITE(header, __user_cap_header_struct_sz);
+  if (res >= 0)
     if (dataptr) POST_WRITE(dataptr, __user_cap_data_struct_sz);
-  }
 }
 
 PRE_SYSCALL(capset)(void *header, const void *data) {
+  if (header) PRE_READ(header, __user_cap_header_struct_sz);
   if (data) PRE_READ(data, __user_cap_data_struct_sz);
 }
 
-POST_SYSCALL(capset)(long res, void *header, const void *data) {
-  if (res >= 0) {
-    if (header) POST_WRITE(header, __user_cap_header_struct_sz);
-  }
-}
+POST_SYSCALL(capset)(long res, void *header, const void *data) {}
 
 PRE_SYSCALL(personality)(long personality) {}
 

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h?rev=201252&r1=201251&r2=201252&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h Wed Feb 12 13:29:49 2014
@@ -184,5 +184,6 @@
 #define SANITIZER_INTERCEPT_GETRESID SI_LINUX
 #define SANITIZER_INTERCEPT_GETIFADDRS SI_LINUX_NOT_ANDROID | SI_MAC
 #define SANITIZER_INTERCEPT_IF_INDEXTONAME SI_LINUX_NOT_ANDROID | SI_MAC
+#define SANITIZER_INTERCEPT_CAPGET SI_LINUX_NOT_ANDROID
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H