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/arm/bits/syscall.h.in b/arch/arm/bits/syscall.h.in
index 8ab5df1d..4d844e57 100644
--- a/arch/arm/bits/syscall.h.in
+++ b/arch/arm/bits/syscall.h.in
@@ -55,7 +55,7 @@
 #define __NR_sethostname	74
 #define __NR_setrlimit	75
 #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
@@ -216,7 +216,7 @@
 #define __NR_timer_getoverrun	260
 #define __NR_timer_delete	261
 #define __NR_clock_settime	262
-#define __NR_clock_gettime	263
+#define __NR_clock_gettime32	263
 #define __NR_clock_getres	264
 #define __NR_clock_nanosleep	265
 #define __NR_statfs64	266