Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Monday, August 29, 2016 10:10:35 PM Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 09:16:29PM +0300, Andrey Chernov wrote: > > Previous text is documented everywhere and describing usual good > > practice, so it should remains in place, in that means r304928 should be > > reverted,

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 29.08.2016 22:10, Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 09:16:29PM +0300, Andrey Chernov wrote: >> Previous text is documented everywhere and describing usual good >> practice, so it should remains in place, in that means r304928 should be >> reverted, because replace proper way

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Mon, Aug 29, 2016 at 2:10 PM, Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 09:16:29PM +0300, Andrey Chernov wrote: > > Previous text is documented everywhere and describing usual good > > practice, so it should remains in place, in that means r304928 should be > >

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Mon, Aug 29, 2016 at 09:16:29PM +0300, Andrey Chernov wrote: > Previous text is documented everywhere and describing usual good > practice, so it should remains in place, in that means r304928 should be > reverted, because replace proper way of doing things with obsoleted > feature description.

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 29.08.2016 21:16, Andrey Chernov wrote: > On 29.08.2016 21:04, Konstantin Belousov wrote: >> On Mon, Aug 29, 2016 at 08:46:47PM +0300, Andrey Chernov wrote: >>> Either we implement this wrapper or left all things as is, we need to >>> document internal errno clearing additionally, to not make

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 29.08.2016 21:04, Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 08:46:47PM +0300, Andrey Chernov wrote: >> Either we implement this wrapper or left all things as is, we need to >> document internal errno clearing additionally, to not make people wonder >> why errno becomes 0, probably

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Mon, Aug 29, 2016 at 09:51:50AM -0700, John Baldwin wrote: > On Monday, August 29, 2016 09:58:13 AM Konstantin Belousov wrote: > > I dug into the ptrace(2) consumers, I found a lot of things using > > it which I would not expect to use, besides usual suspects of gdb > > lldb libunwind reptyr

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 29.08.2016 19:51, John Baldwin wrote: >> int >> ptrace(int request, pid_t pid, caddr_t addr, int data) >> { >> >> errno = 0; >> return (__sys_ptrace(request, pid, addr, data)); >> } > > Certainly I think having a C wrapper like this makes more sense than > doing it all in assembly N

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Monday, August 29, 2016 09:58:13 AM Konstantin Belousov wrote: > On Sun, Aug 28, 2016 at 04:09:51PM -0700, John Baldwin wrote: > > OTOH, given that we explicitly documented it as not being true, I suspect > > any applications that are using ptrace() are going off the documentation, > > not > >

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 29.08.2016 18:34, Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 06:05:50PM +0300, Andrey Chernov wrote: >> No surprise since they all share the same initial implementation. You >> can add NetBSD and OpenBSD too. Errno clearing as undocumented side >> effect is not what we need, and every

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Mon, Aug 29, 2016 at 06:05:50PM +0300, Andrey Chernov wrote: > No surprise since they all share the same initial implementation. You > can add NetBSD and OpenBSD too. Errno clearing as undocumented side > effect is not what we need, and every system documents that user must > clear errno. Of

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 29.08.2016 10:07, Konstantin Belousov wrote: > On Mon, Aug 29, 2016 at 09:58:13AM +0300, Konstantin Belousov wrote: >> On Sun, Aug 28, 2016 at 04:09:51PM -0700, John Baldwin wrote: >>> OTOH, given that we explicitly documented it as not being true, I suspect >>> any applications that are using

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Mon, Aug 29, 2016 at 09:58:13AM +0300, Konstantin Belousov wrote: > On Sun, Aug 28, 2016 at 04:09:51PM -0700, John Baldwin wrote: > > OTOH, given that we explicitly documented it as not being true, I suspect > > any applications that are using ptrace() are going off the documentation, > > not

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Sun, Aug 28, 2016 at 04:09:51PM -0700, John Baldwin wrote: > OTOH, given that we explicitly documented it as not being true, I suspect > any applications that are using ptrace() are going off the documentation, not > the implementation artifact. Note that Linux's ptrace() documents the same >

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Sunday, August 28, 2016 04:52:10 AM Konstantin Belousov wrote: > On Sun, Aug 28, 2016 at 04:25:46AM +0300, Andrey Chernov wrote: > > On 28.08.2016 4:15, Konstantin Belousov wrote: > > >> POSIX: "No function in this volume of POSIX.1-2008 shall set errno to > > >> zero." > > > I am quite

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 8:28, Bruce Evans wrote: >> How hard it will be to bring ptrace() to what C99 expects? Perhaps now >> time is suited well to change some obsoleted things. > > This should be safe to change, since portable applications like gdb can't > assume that the implemementation clobbers errno

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Sun, 28 Aug 2016, Andrey Chernov wrote: On 28.08.2016 4:52, Konstantin Belousov wrote: POSIX: "For each thread of a process, the value of errno shall not be affected by function calls or assignments to errno by other threads." And ? What should the citation add new to the substance of the

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 5:33, Andrey Chernov wrote: > "conforming implementation may have extensions (including additional > library functions), provided they do not alter the behavior of any > strictly conforming program.3)" > > ptrace() is extension (additional library function) so can't set errno > to 0

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 4:52, Konstantin Belousov wrote: POSIX: "For each thread of a process, the value of errno shall not be affected by function calls or assignments to errno by other threads." >>> And ? What should the citation add new to the substance >>> of the code change ? >> >> This is

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Sun, Aug 28, 2016 at 04:25:46AM +0300, Andrey Chernov wrote: > On 28.08.2016 4:15, Konstantin Belousov wrote: > >> POSIX: "No function in this volume of POSIX.1-2008 shall set errno to > >> zero." > > I am quite curious where ptrace(2) is defined by POSIX. > > POSIX just repeats C99 statement

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 4:37, Andrey Chernov wrote: > On 28.08.2016 4:25, Andrey Chernov wrote: >>> Point me to a single line in C99 which mentions ptrace(). > > Already done: ptrace == "any library function". To elaborate it more, C99 does not have finite list of library functions, but it says about

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 4:25, Andrey Chernov wrote: >> Point me to a single line in C99 which mentions ptrace(). Already done: ptrace == "any library function". ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 4:15, Konstantin Belousov wrote: >> POSIX: "No function in this volume of POSIX.1-2008 shall set errno to zero." > I am quite curious where ptrace(2) is defined by POSIX. POSIX just repeats C99 statement for its own functions, supporting this rule too, but C99 rule is more general

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 4:04, Andrey Chernov wrote: > On 28.08.2016 3:56, Konstantin Belousov wrote: >> On Sun, Aug 28, 2016 at 03:38:10AM +0300, Andrey Chernov wrote: >>> On 28.08.2016 2:03, Konstantin Belousov wrote: Since ptrace(2) syscall can return -1 for non-error situations, libc

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Sun, Aug 28, 2016 at 03:50:04AM +0300, Andrey Chernov wrote: > On 28.08.2016 3:38, Andrey Chernov wrote: > > On 28.08.2016 2:03, Konstantin Belousov wrote: > >> Since ptrace(2) syscall can return -1 for non-error situations, libc > >> wrappers set errno to 0 before performing the syscall,

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 3:56, Konstantin Belousov wrote: > On Sun, Aug 28, 2016 at 03:38:10AM +0300, Andrey Chernov wrote: >> On 28.08.2016 2:03, Konstantin Belousov wrote: >>> Since ptrace(2) syscall can return -1 for non-error situations, libc >>> wrappers set errno to 0 before performing the syscall,

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On Sun, Aug 28, 2016 at 03:38:10AM +0300, Andrey Chernov wrote: > On 28.08.2016 2:03, Konstantin Belousov wrote: > > Since ptrace(2) syscall can return -1 for non-error situations, libc > > wrappers set errno to 0 before performing the syscall, as the service > > to the caller. > > Both C99

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 3:38, Andrey Chernov wrote: > On 28.08.2016 2:03, Konstantin Belousov wrote: >> Since ptrace(2) syscall can return -1 for non-error situations, libc >> wrappers set errno to 0 before performing the syscall, as the service >> to the caller. > > Both C99 and POSIX directly

Re: svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

On 28.08.2016 2:03, Konstantin Belousov wrote: > Since ptrace(2) syscall can return -1 for non-error situations, libc > wrappers set errno to 0 before performing the syscall, as the service > to the caller. Both C99 and POSIX directly prohibits any standard function to set errno to 0.

svn commit: r304928 - in head/lib/libc: amd64/sys i386/sys sys

Author: kib Date: Sat Aug 27 23:03:23 2016 New Revision: 304928 URL: https://svnweb.freebsd.org/changeset/base/304928 Log: Do not obliterate errno value in the main thread during ptrace(2) call on x86. Since ptrace(2) syscall can return -1 for non-error situations, libc wrappers set