Index: sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc |
diff --git a/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc b/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc |
index c4a6f92c01d423521aee83ffcaf2e4cc35f4e82a..7e4aac29f5e3c190229a93dee294f0dd592917ec 100644 |
--- a/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc |
+++ b/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc |
@@ -44,11 +44,29 @@ void WriteToStdErr(const char* error_message, size_t size) { |
} |
} |
+uint32_t TruncSysnoToValue(uint32_t sysno) { |
+#if defined(__mips__) |
+ // On MIPS syscall numbers are in different range than on x86 and ARM |
+ if (sysno < __NR_Linux || sysno > __NR_Linux + __NR_Linux_syscalls) |
+ // 4000 (truncated to zero) is valid syscall number on mips O32 ABI. |
+ // Invalid syscall will be printed with a value that is out of range |
+ // on apropriate ABI. |
+ sysno = sysno - __NR_Linux + 1000; |
jln (very slow on Chromium)
2014/05/16 19:30:17
I don't understand what this does.
Please documen
nedeljko
2014/05/19 17:37:23
On MIPS O32 ABI value of __NR_Linux is 4000.
The
nedeljko
2014/05/22 17:38:55
Done.
|
+ else |
+ sysno = sysno - __NR_Linux; |
+#else |
+ if (sysno >= 1024) |
+ sysno = 0; |
+#endif |
+ return sysno; |
+} |
+ |
// Print a seccomp-bpf failure to handle |sysno| to stderr in an |
// async-signal safe way. |
void PrintSyscallError(uint32_t sysno) { |
- if (sysno >= 1024) |
- sysno = 0; |
+ |
+ sysno = TruncSysnoToValue(sysno); |
+ |
// TODO(markus): replace with async-signal safe snprintf when available. |
const size_t kNumDigits = 4; |
char sysno_base10[kNumDigits]; |
@@ -59,8 +77,14 @@ void PrintSyscallError(uint32_t sysno) { |
rem /= 10; |
sysno_base10[i] = '0' + mod; |
} |
+#if defined(__mips__) && (_MIPS_SIM == _MIPS_SIM_ABI32) |
+ static const char kSeccompErrorPrefix[] = |
+ __FILE__":**CRASHING**:" SECCOMP_MESSAGE_COMMON_CONTENT |
+ " in syscall 4000 + "; |
+#else |
static const char kSeccompErrorPrefix[] = |
__FILE__":**CRASHING**:" SECCOMP_MESSAGE_COMMON_CONTENT " in syscall "; |
+#endif |
static const char kSeccompErrorPostfix[] = "\n"; |
WriteToStdErr(kSeccompErrorPrefix, sizeof(kSeccompErrorPrefix) - 1); |
WriteToStdErr(sysno_base10, sizeof(sysno_base10)); |
@@ -73,8 +97,7 @@ namespace sandbox { |
intptr_t CrashSIGSYS_Handler(const struct arch_seccomp_data& args, void* aux) { |
uint32_t syscall = args.nr; |
- if (syscall >= 1024) |
- syscall = 0; |
+ |
PrintSyscallError(syscall); |
// Encode 8-bits of the 1st two arguments too, so we can discern which socket |