From: Mike Frysinger <vapier@gentoo.org>
To: Tsukasa OI <research_trasio@irq.a4lg.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH 22/40] sim/m32r: Fixes to Linux emulator
Date: Thu, 27 Oct 2022 21:50:27 +0545 [thread overview]
Message-ID: <Y1qsR/K84VKMhLVk@vapier> (raw)
In-Reply-To: <b31b6551-c88f-eb09-37bd-e1e84be96243@irq.a4lg.com>
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On 27 Oct 2022 11:40, Tsukasa OI wrote:
> On 2022/10/23 23:56, Mike Frysinger wrote:
> > On 20 Oct 2022 09:32, Tsukasa OI wrote:
> >> 2. syslog function must be called as a syscall rather than POSIX syslog
> >> because we are emulating Linux system calls on the Linux host.
> >
> > i don't think that is accurate. if that were true, every other call in here
> > would be using syscall() instead of calling the C library functions.
>
> Note that this part is a Linux to Linux syscall translator (though I
> consider this whole idea unsafe). Yes, it uses many C library functions
> but I consider this is because they are (almost/completely) compatible
> with underlying syscalls.
this is incorrect. let's take a step back. the point of the sim runtime
environments is to emulate the specified userland regardless of the host
OS. it is not a linux-to-linux translator. the runtime decodes syscalls,
then attempts to emulate the requested behavior. ideally that would only
ever involve going through the standard C library APIs.
the m32r linux runtime environment layer has a bunch of linuxisms in there
(because it can be hard to emulate linux behavior on non-linux systems).
but that doesn't mean it's a linux-to-linux layer, and we shouldn't be
making it worse.
> However, this isn't the case for syslog. POSIX syslog (C library
> function on <syslog.h>) and Linux syslog (syscall) have very different
> semantics and Linux syslog should be used here.
you are correct here.
the arch backends for diff runtime environments are inconsistent whether
they pass through to the real host env, or they provide stub/fake data so
the program doesn't get real access to the host (basically constructing a
sandbox). i see the value in both modes (especially since a sandbox is
easier to run cross-OS), but haven't fleshed out how to support these.
> Probably using glibc wrapper klogctl (<sys/klog.h>) might be a solution
> (see man page syslog.2). I would like to hear your thoughts.
klogctl would be OK
-mike
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next prev parent reply other threads:[~2022-10-27 17:19 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-20 9:32 [PATCH 00/40] sim+gdb: Suppress warnings if built with Clang (big batch 1) Tsukasa OI
2022-10-20 9:32 ` [PATCH 01/40] gdb/unittests: PR28413, suppress warnings generated by Gnulib Tsukasa OI
2022-11-14 14:01 ` Simon Marchi
2022-10-20 9:32 ` [PATCH 02/40] sim: Check known getrusage declaration existence Tsukasa OI
2022-10-23 13:59 ` Mike Frysinger
2022-10-24 10:47 ` Tsukasa OI
2022-10-24 16:03 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 03/40] sim/aarch64: Remove unused functions Tsukasa OI
2022-10-23 14:02 ` Mike Frysinger
2022-10-24 10:55 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 04/40] cpu/cris: Initialize some variables on CRIS CPU Tsukasa OI
2022-10-20 9:32 ` [PATCH 05/40] cpu/cris: Add u-stall virtual unit to CRIS v32 Tsukasa OI
2022-10-20 9:32 ` [PATCH 06/40] sim/cris: Move declarations of f_specific_init Tsukasa OI
2022-10-23 14:26 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 07/40] sim/cris: Regenerate with CGEN Tsukasa OI
2022-10-23 14:27 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 08/40] sim/erc32: Insert void parameter Tsukasa OI
2022-10-23 14:04 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 09/40] sim/erc32: Use int32_t as event callback argument Tsukasa OI
2022-10-23 14:32 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 10/40] sim/erc32: Use int32_t as IRQ " Tsukasa OI
2022-10-23 14:33 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 11/40] cpu/frv: Initialize some variables Tsukasa OI
2022-10-20 9:32 ` [PATCH 12/40] sim/frv: Initialize nesr variable Tsukasa OI
2022-10-23 14:39 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 13/40] sim/frv: Initialize some variables Tsukasa OI
2022-10-23 14:34 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 14/40] sim/frv: Add explicit casts Tsukasa OI
2022-10-23 14:40 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 15/40] sim/h8300: Add "+ 0x0" to avoid self-assignments Tsukasa OI
2022-10-23 14:05 ` Mike Frysinger
2022-10-24 10:55 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 16/40] sim/lm32: fix some missing function declaration warnings Tsukasa OI
2022-10-23 14:41 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 17/40] sim/lm32: Add explicit casts Tsukasa OI
2022-10-23 14:42 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 18/40] sim/m32c: Stop using middle dot Tsukasa OI
2022-10-23 14:48 ` Mike Frysinger
2022-10-27 2:08 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 19/40] sim/m32r: Initialize "list" variable Tsukasa OI
2022-10-23 14:50 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 20/40] sim/m32r: Prepare required functions Tsukasa OI
2022-10-23 14:53 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 21/40] sim/m32r: Declare all " Tsukasa OI
2022-10-23 14:54 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 22/40] sim/m32r: Fixes to Linux emulator Tsukasa OI
2022-10-23 14:56 ` Mike Frysinger
2022-10-27 2:40 ` Tsukasa OI
2022-10-27 16:05 ` Mike Frysinger [this message]
2022-10-20 9:32 ` [PATCH 23/40] sim/m32r: Add explicit casts Tsukasa OI
2022-10-23 14:57 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 24/40] sim/mips: Fix enum type-related issues on cp1.c Tsukasa OI
2022-10-23 15:00 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 25/40] sim/mn10300: Add an explicit cast Tsukasa OI
2022-10-23 15:03 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 26/40] sim/ppc: Remove getrusage declarations if possible Tsukasa OI
2022-10-23 15:04 ` Mike Frysinger
2022-10-27 2:00 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 27/40] sim/ppc: Add extra parenthesis to avoid ambiguity Tsukasa OI
2022-10-23 15:05 ` Mike Frysinger
2022-10-24 10:59 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 28/40] sim/ppc: Initialize stat type buffer Tsukasa OI
2022-10-23 15:06 ` Mike Frysinger
2022-10-24 11:00 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 29/40] sim/ppc: Fix indentation on generated code Tsukasa OI
2022-10-23 15:07 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 30/40] sim/ppc: Use TRACE with initialized entry_point Tsukasa OI
2022-10-23 15:08 ` Mike Frysinger
2022-10-24 11:02 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 31/40] sim/ppc: Initialize help variables Tsukasa OI
2022-10-23 15:08 ` Mike Frysinger
2022-10-24 16:33 ` Andrew Burgess
2022-10-20 9:32 ` [PATCH 32/40] sim/ppc: Add an explicit cast Tsukasa OI
2022-10-23 15:10 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 33/40] sim/ppc: Initialize reg and control_nr Tsukasa OI
2022-10-23 15:14 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 34/40] sim/rx: Mark unused function Tsukasa OI
2022-10-23 15:14 ` Mike Frysinger
2022-10-24 16:30 ` Andrew Burgess
2022-10-29 11:58 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 35/40] sim/sh: Initialize some variables Tsukasa OI
2022-10-23 15:19 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 36/40] sim/sh: Use fabs instead of abs Tsukasa OI
2022-10-23 14:17 ` Mike Frysinger
2022-10-24 10:56 ` Tsukasa OI
2022-10-20 9:32 ` [PATCH 37/40] sim/sh: Remove redundant function declaration Tsukasa OI
2022-10-23 14:19 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 38/40] sim/bpf: Add explicit casts Tsukasa OI
2022-10-23 15:15 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 39/40] sim/iq2000: " Tsukasa OI
2022-10-23 15:16 ` Mike Frysinger
2022-10-20 9:32 ` [PATCH 40/40] sim/or1k: " Tsukasa OI
2022-10-23 15:16 ` Mike Frysinger
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