remove legacy clock_gettime and gettimeofday from public syscall.h

some nontrivial number of applications have historically performed
direct syscalls for these operations rather than using the public
functions. such usage is invalid now that time_t is 64-bit and these
syscalls no longer match the types they are used with, and it was
already harmful before (by suppressing use of vdso).

since syscall() has no type safety, incorrect usage of these syscalls
can't be caught at compile-time. so, without manually inspecting or
running additional tools to check sources, the risk of such errors
slipping through is high.

this patch renames the syscalls on 32-bit archs to clock_gettime32 and
gettimeofday_time32, so that applications using the original names
will fail to build without being fixed.

note that there are a number of other syscalls that may also be unsafe
to use directly after the time64 switchover, but (1) these are the
main two that seem to be in widespread use, and (2) most of the others
continue to have valid usage with a null timeval/timespec argument, as
the argument is an optional timeout or similar.

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/bits/syscall.h.in b/arch/powerpc/bits/syscall.h.in
index d8b6a247..14cf79c6 100644
--- a/arch/powerpc/bits/syscall.h.in
+++ b/arch/powerpc/bits/syscall.h.in
@@ -76,7 +76,7 @@
 #define __NR_setrlimit               75
 #define __NR_getrlimit               76
 #define __NR_getrusage               77
-#define __NR_gettimeofday            78
+#define __NR_gettimeofday_time32            78
 #define __NR_settimeofday            79
 #define __NR_getgroups               80
 #define __NR_setgroups               81
@@ -243,7 +243,7 @@
 #define __NR_timer_getoverrun       243
 #define __NR_timer_delete           244
 #define __NR_clock_settime          245
-#define __NR_clock_gettime          246
+#define __NR_clock_gettime32          246
 #define __NR_clock_getres           247
 #define __NR_clock_nanosleep        248
 #define __NR_swapcontext            249