Commit Graph

5 Commits

Author SHA1 Message Date
Alistair Francis
0bcd0c5100 sysv/alpha: Use generic __timeval32 and helpers
Now there is a generic __timeval32 and helpers we can use them for Alpha
instead of the Alpha specific ones.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-04-02 09:21:06 -07:00
Alistair Francis
4da2597af5 sysv/linux: Rename alpha functions to be alpha specific
These functions are alpha specifc, rename them to be clear.

Let's also rename the header file from tv32-compat.h to
alpha-tv32-compat.h. This is to avoid conflicts with the one we will
introduce later.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-03-27 11:23:15 -07:00
Lukasz Majewski
cde52c2557 y2038: alpha: Rename valid_timeval_to_timeval64 to valid_timeval32_to_timeval
Without this patch the naming convention for functions to convert
struct timeval32 to struct timeval (which supports 64 bit time on Alpha) was
a bit misleading. The name 'valid_timeval_to_timeval64' suggest conversion
of struct timeval to struct __timeval64 (as in ./include/time.h).

As on alpha the struct timeval supports 64 bit time it seems more readable
to emphasis struct timeval32 in the conversion function name.

Hence the helper function naming change to 'valid_timeval32_to_timeval'.

Build tests:
./src/scripts/build-many-glibcs.py glibcs

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-02-07 17:55:08 +01:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Zack Weinberg
04da832e16 Linux/Alpha: don't use timeval32 system calls.
Linux/Alpha has two versions of several system call wrappers that take
or return data of type "struct timeval" (possibly nested inside a
larger structure).  The GLIBC_2.0 version is a compat symbol that
calls __NR_osf_foo or __NR_old_foo and uses a struct timeval with a
32-bit tv_sec field.  The GLIBC_2.1 version is used for current code,
calls __NR_foo, and uses a struct timeval with a 64-bit tv_sec field.

This patch changes all of the compat symbols of this type to be
wrappers around their GLIBC_2.1 counterparts; the compatibility system
calls will no longer be used.  It serves as a proposal for part of how
we do the transition to 64-bit time_t on systems that currently use
32-bit time_t:

 * The patched glibc will NOT use system calls that involve 32-bit
   time_t to implement its compatibility symbols.  This will make both
   our lives and the kernel maintainers' lives easier.  The primary
   argument I've seen against it is that the kernel could warn about
   uses of the old system calls, helping people find old binaries that
   need to be recompiled.  I think there are several other ways we
   could accomplish this, e.g. scripts to scan the filesystem for
   binaries with references to the old symbol versions, or issuing
   diagnostics ourselves.

 * The compat symbols do NOT report failure after the Y2038 deadline.
   An earlier revision of this patch had them return -1 and set errno
   to EOVERFLOW, but Adhemerval pointed out that many of them have
   already performed side effects at the point where we discover the
   overflow, so that would break more than it fixes.  Also, we don't
   want people to be _checking_ for EOVERFLOW from these functions; we
   want them to recompile with 64-bit time_t.  So it's not actually
   useful for them to report failure to the calling code.

 * What they do do, when they encounter overflow, is saturate the
   overflowed "struct timeval"(s): tv_sec is set to INT32_MAX and
   tv_nsec is set to 999999.  That means time stops advancing for
   programs with 32-bit time_t when they reach the deadline.  That's
   obviously going to break stuff, but I think wrapping around is
   probably going to break _more_ stuff.  I'd be interested to hear
   arguments against, if anyone has one.

The new header file tv32-compat.h is currently Alpha-specific but I
mean for it to be reused to aid in writing wrappers for all affected
architectures.  I only put it in sysdeps/unix/sysv/linux/alpha for now
because I haven't checked whether the various "foo32" structures it
defines agree with the ABI for ports other than Linux/Alpha.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-10-30 17:03:42 -03:00