From: Roman Bolshakov <r.bolshakov@yadro.com>
To: David CARLIER <devnexen@gmail.com>
Cc: qemu-trivial@nongnu.org, pbonzini@redhat.com, qemu-devel@nongnu.org
Subject: Re: [PATCH] util/oslib-posix : qemu_init_exec_dir implementation for MacOS
Date: Mon, 8 Jun 2020 09:02:52 +0300 [thread overview]
Message-ID: <20200608060252.GD27616@SPB-NB-133.local> (raw)
In-Reply-To: <CA+XhMqwH6btbKFD0Ei47e+QHN2eBPG5H2PTS92MAje2Tij4Y=A@mail.gmail.com>
On Tue, May 26, 2020 at 09:40:27PM +0100, David CARLIER wrote:
> From b24a6702beb2a4e2a9c1c03b69c6d1dd07d4cf08 Mon Sep 17 00:00:00 2001
> From: David Carlier <devnexen@gmail.com>
> Date: Tue, 26 May 2020 21:35:27 +0100
> Subject: [PATCH] util/oslib: current process full path resolution on MacOS
>
> Using existing libproc to fill the path.
>
> Signed-off-by: David Carlier <devnexen@gmail.com>
> ---
> util/oslib-posix.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index 062236a1ab..96f0405ee6 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -55,6 +55,10 @@
> #include <sys/sysctl.h>
> #endif
>
> +#ifdef __APPLE__
> +#include <libproc.h>
> +#endif
> +
> #include "qemu/mmap-alloc.h"
>
> #ifdef CONFIG_DEBUG_STACK_USAGE
> @@ -366,6 +370,15 @@ void qemu_init_exec_dir(const char *argv0)
> p = buf;
> }
> }
> +#elif defined(__APPLE__)
> + {
> + uint32_t len;
> + len = proc_pidpath(getpid(), buf, sizeof(buf) - 1);
Hi David,
proc_pidpath handler in the xnu kernel is indirectly calling
build_path_with_parent [1] and it includes NULL terminator into
buffersize, i.e. the patch seems to limit path length to one less
character than OS allows.
> + if (len > 0) {
> + buf[len] = 0;
> + p = buf;
> + }
> + }
> #endif
> /* If we don't have any way of figuring out the actual executable
> location then try argv[0]. */
> --
> 2.26.2
>
The change looks okay but it's not clear why it is needed [2].
Also, libproc.h [3] has this comment:
/*
* This header file contains private interfaces to obtain process information.
* These interfaces are subject to change in future releases.
*/
But iTerm2 [4] an Chromium [5] are using it. An alternative (if it works
and IMO less appealing) would be to retrieve process path using AppKit [6].
1. https://opensource.apple.com/source/xnu/xnu-6153.81.5/bsd/vfs/vfs_cache.c.auto.html
2. https://wiki.qemu.org/Contribute/SubmitAPatch#Write_a_meaningful_commit_message
3. https://opensource.apple.com/source/xnu/xnu-6153.81.5/libsyscall/wrappers/libproc/libproc.h.auto.html
4. https://gitlab.com/gnachman/iterm2/blob/872e3d63fbcaf7b4235c4f3b7273e09a7ba4c1d1/sources/iTermLSOF.m#L31
5. https://github.com/chromium/chromium/blob/2ca8c5037021c9d2ecc00b787d58a31ed8fc8bcb/base/process/process_handle_mac.cc#L31
6. https://developer.apple.com/documentation/appkit/nsworkspace?language=objc
Regards,
Roman
prev parent reply other threads:[~2020-06-08 6:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 20:40 [PATCH] util/oslib-posix : qemu_init_exec_dir implementation for MacOS David CARLIER
2020-05-26 22:25 ` David CARLIER
2020-06-03 6:08 ` Philippe Mathieu-Daudé
2020-06-03 6:16 ` David CARLIER
2020-06-03 14:09 ` Justin Hibbits
2020-06-03 14:22 ` David CARLIER
2020-06-03 14:38 ` Philippe Mathieu-Daudé
2020-06-15 16:26 ` Peter Maydell
2020-06-03 14:36 ` Philippe Mathieu-Daudé
2020-06-03 16:08 ` Justin Hibbits
2020-06-08 6:02 ` Roman Bolshakov [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200608060252.GD27616@SPB-NB-133.local \
--to=r.bolshakov@yadro.com \
--cc=devnexen@gmail.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-trivial@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).