[ESan] [MIPS] Fix workingset-signal-posix.cpp on MIPS

[slthakur]

Summary

• Used uptr for __sanitizer_kernel_sigset_t.sig to avoid byte order issues on big endian systems
• Corrected the data type of __sanitizer_kernel_sigaction_t.sa_flags which is unsigned int

[bruening]

lib/sanitizer_common/sanitizer_platform_limits_posix.h

610

Aren't there references in source code files that need to be updated for this change? At a glance I see things like "(sizeof(k_set->sig[0]) * 8)".

[slthakur]

lib/sanitizer_common/sanitizer_platform_limits_posix.h

610

There the two functions which reference __sanitizer_kernel_sigset_t.sig:

• internal_sigdelset
• internal_sigismember

Both of these functions were producing wrong results on big endian machines because __sanitizer_kernel_sigset_t.sig was declared as a char array. Both these functions return correct result with this change.

[slthakur]

Ping?

[seanbruno]

This review *looks* like it has addressed all comment feedback. Does it need to be recreated against trunk?

[bruening]

lib/sanitizer_common/sanitizer_platform_limits_posix.h

610

OK, you're saying that the *kernel* defines the signal set array as some multi-byte structure (unsigned long) and thus endian-ness comes into play between the sanitizer code and the kernel.

[slthakur]

Committed revision 283438

lib/sanitizer_common/sanitizer_platform_limits_posix.h

610

Yes.

lib/sanitizer_common/sanitizer_platform_limits_posix.h

 #endif
   };
 #endif // !SANITIZER_ANDROID
 
 #if SANITIZER_FREEBSD
   typedef __sanitizer_sigset_t __sanitizer_kernel_sigset_t;
 #elif defined(__mips__)
   struct __sanitizer_kernel_sigset_t {
-    u8 sig[16];
+    uptr sig[2];
   };
 #else
   struct __sanitizer_kernel_sigset_t {
     u8 sig[8];
   };
 #endif
 
   // Linux system headers define the 'sa_handler' and 'sa_sigaction' macros.
   struct __sanitizer_kernel_sigaction_t {
 #if SANITIZER_MIPS
-    unsigned long sa_flags;
+    unsigned int sa_flags;
 #endif
     union {
       void (*handler)(int signo);
       void (*sigaction)(int signo, void *info, void *ctx);
     };
 #if !SANITIZER_MIPS
     unsigned long sa_flags;
     void (*sa_restorer)(void);