Date: Thu, 5 Jun 2025 09:54:29 -0700 From: Warner Losh <imp@bsdimp.com> To: John Baldwin <jhb@freebsd.org> Cc: Kyle Evans <kevans@freebsd.org>, Gleb Smirnoff <glebius@freebsd.org>, markj@freebsd.org, src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 969f6380eb66 - main - kdump: nicer printing of kill(2) PID argument Message-ID: <CANCZdfoCU=t=s2g5u7Ng_9jpdvXA8BMLCv4Dw0HNeTKn1GbVCg@mail.gmail.com> In-Reply-To: <0b4a1945-8f75-4f57-9a57-5bd0c10a7af1@FreeBSD.org> References: <202506040151.5541pESm016476@gitrepo.freebsd.org> <aEDO_3cfSbx2JnCG@cell.glebi.us> <02ed6d30-b22a-456d-96e2-7f5b235766fd@FreeBSD.org> <0b4a1945-8f75-4f57-9a57-5bd0c10a7af1@FreeBSD.org>
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On Thu, Jun 5, 2025 at 6:14 AM John Baldwin <jhb@freebsd.org> wrote: > > On 6/4/25 19:03, Kyle Evans wrote: > > On 6/4/25 17:55, Gleb Smirnoff wrote: > >> On Wed, Jun 04, 2025 at 01:51:14AM +0000, Kyle Evans wrote: > >> K> The branch main has been updated by kevans: > >> K> > >> K> URL: https://cgit.FreeBSD.org/src/commit/?id=969f6380eb66f809eed3e5c38b6021824a4cc2bf > >> K> > >> K> commit 969f6380eb66f809eed3e5c38b6021824a4cc2bf > >> K> Author: Kyle Evans <kevans@FreeBSD.org> > >> K> AuthorDate: 2025-06-04 01:51:06 +0000 > >> K> Commit: Kyle Evans <kevans@FreeBSD.org> > >> K> CommitDate: 2025-06-04 01:51:06 +0000 > >> K> > >> K> kdump: nicer printing of kill(2) PID argument > >> K> > >> K> Similar to wait*(), kill(2) operates on a pid that currently gets output > >> K> as hex. Output it in decimal to make it a little easier to eyeball the > >> K> pid we're signalling. > >> K> > >> K> Reviewed by: markj > >> K> Differential Revision: https://reviews.freebsd.org/D50508 > >> > >> I didn't review if PIDs are always printed as decimals or not, but for > >> the file descriptors it is a mix of hex and decimals. :( Usually I go > >> with a sed script over kdump output to make it consistent. > >> > > > > To be fair, I'd like to fix that, too- I noticed close() the other day > > for fd > 0, but paused when I: > > > > 1.) couldn't tell where we even output close args > > close is probably handled by the default case where where all of the > arguments are just output as hex values. Note that for kdump, most > syscalls fall into this case including syscalls with pointer arguments. > You'd probably be a bit sad with 64-bit pointers printed as decimal > for many system calls. > > truss is different as truss stores some rudimentary type information about > system call arguments and then defaults to printing certain types like > file descriptors and ids as decimal. truss also prints NULL for null > pointers IIRC. > > A useful project perhaps would be to move the table describing system > call argument types out of syscalls.c in truss and into libsysdecode so > that kdump could also reuse it. Probably the API you would want is > something that returns an individual `struct syscall_decode` given > (ABI, number) input arguments. Yes. All this generation is why we did the lua project to make the master system call table parsing into a library. We need it also for qemu-bsd-user long-term: writing new system calls by hand is a pain and error-prone. > I don't think you can generate this table automatically from makesyscalls.lua > as many of the "types" truss uses are synthetic types that aren't visible > in C, e.g. "OpenFlags" meaning O_* flags passed to open(2). I think that we should, in the fullness of time, flag these so we can do that. If we do add additional notations, we can not only have better truss/trace output, as well as being able to generate the right flag translations for running FreeBSD binaries on Linux (which people are doing by hand right now...). > This would allow kdump's hand-written per-syscall-number rules to instead > be closer to truss where you instead just iterate over types. It would > also mean only having to update a single table in libsysdecode when adding > a new system call to add both truss and kdump support. Only when a new > argument type is added would one have to actually touch truss or kdump > directly. I'd love for this to be generated as well... It was certainly one of the use cases that we had in mind for the GSOC project that did this. Warnerhome | help
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