This patch fix powerpc __get_clockfreq racy and cancel-safe issues by
dropping internal static cache and by using nocancel file operations.
The vDSO failure check is also removed, since kernel code does not
return an error (it cleans cr0.so bit on function return) and the static
code (to read value /proc) now uses non-cancellable calls.
In my powerpc32 testing I've observed misc/test-gettimebasefreq
failing.
This is a glibc build (soft-float, though that's not relevant here)
without any --with-cpu and without any special configuration of the
default CPU for GCC either. In particular, it's one not using
sysdeps/powerpc/powerpc32/power4/hp-timing.h (although in fact the
processor I'm using for testing is POWER4-based), so hp_timing_t is
32-bit not 64-bit. But the VDSO call being used by
INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK is generating a 64-bit result
(high part in r3, low part in r4). The code extracting that result,
however, expects a result of the type hp_timing_t as passed to
INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK, meaning that only r3 (= 0) is
used and the value in r4 is ignored. This patch fixes this by always
using uint64_t as the type in INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK -
reflecting the actual ABI (unconditional in the kernel) of that VDSO
call. This is the minimal change for this issue - no check for
overflow, no change of the type of the timebase_freq variable or the
return type of __get_clockfreq to something other than hp_timing_t
(such a change would simply move the implicit conversions to the over
callers of that function), no change to hp_timing_t itself.
Tested for powerpc32 soft float.
[BZ #17263]
* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c: Include
<stdint.h>.
(__get_clockfreq): Use uint64_t instead of hp_timing_t in
INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK call.
In order for the __kernel_get_tbfreq vDSO call to work the
INTERNAL_VSYSCALL_NCS macro needed to be updated to prevent it from
assuming an integer return type (since the timebase frequency is a 64-bit
value) by specifying the type of the return type as a macro parameter. The
macro then specifically declares the return value as a 'register' (or
implied pair) of the denoted type. The compiler is then informed that this
register (or implied pair) is to be used for the return value.
Tom Gall <tom_gall@vnet.ibm.com>
* elf/rtld.c (dl_main): Initialize l_local_scope for sysinfo_map.
* sysdeps/powerpc/elf/libc-start.c: Move this...
* sysdeps/unix/sysv/linux/powerpc/libc-start.c: ...to here.
* sysdeps/powerpc/powerpc32/dl-start.S: Add _dl_main_dispatch label.
* sysdeps/powerpc/powerpc32/hp-timing.h: New file.
* sysdeps/unix/sysv/linux/powerpc/Versions: New file.
* sysdeps/unix/sysv/linux/clock_getres.c: If HAVE_CLOCK_GETRES_VSYSCALL
is not defined, redefine INTERNAL_VSYSCALL and INLINE_VSYSCALL to
INTERNAL_SYSCALL and INLINE_SYSCALL respectively. Otherwise include
<bits/libc-vdso.h>. Use INLINE_VSYSCALL and INTERNAL_SYSCALL instead
of the normal versions throughout the code.
* sysdeps/unix/sysv/linux/clock_gettime.c: Likewise if
HAVE_CLOCK_GETTIME_VSYSCALL is defined.
* sysdeps/unix/sysv/linux/powerpc/bits/libc-vdso.h: New file.
* sysdeps/unix/sysv/linux/powerpc/dl-vdso.c: New file.
* sysdeps/unix/sysv/linux/powerpc/dl-vdso.h: New file.
* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c: Use vDSO.
* sysdeps/unix/sysv/linux/powerpc/gettimeofday.c: New file.
* sysdeps/unix/sysv/linux/powerpc/Makefile: Add dl-vdso to routines.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h: Define
INLINE_VSYSCALL, INTERNAL_VSYSCALL, INTERNAL_SYSCALL_NCS,
INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK, HAVE_CLOCK_GETRES_VSYSCALL,
and HAVE_CLOCK_GETTIME_VSYSCALL.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h: Likewise.
