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From: "Alex Bennée" <alex.bennee@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Thomas Huth" <thuth@redhat.com>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Beraldo Leal" <bleal@redhat.com>,
	"Mahmoud Mandour" <ma.mandourr@gmail.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>,
	"Wainer dos Santos Moschetta" <wainersm@redhat.com>,
	qemu-arm@nongnu.org, "Alexandre Iooss" <erdnaxe@crans.org>
Subject: [PATCH 06/10] docs/emulation: expand warning about semihosting
Date: Wed, 15 Nov 2023 20:55:38 +0000	[thread overview]
Message-ID: <20231115205542.3092038-7-alex.bennee@linaro.org> (raw)
In-Reply-To: <20231115205542.3092038-1-alex.bennee@linaro.org>

A surprising feature of calls like SYS_READC is this can cause QEMU to
indefinitely block as there is no handling for EOF.

Clarifies: https://gitlab.com/qemu-project/qemu/-/issues/1963
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 docs/about/emulation.rst | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/docs/about/emulation.rst b/docs/about/emulation.rst
index 0ad0b86f0d..a2eefe3f3f 100644
--- a/docs/about/emulation.rst
+++ b/docs/about/emulation.rst
@@ -129,8 +129,9 @@ causing most hypervisors to trap and fault on them.
 .. warning::
    Semihosting inherently bypasses any isolation there may be between
    the guest and the host. As a result a program using semihosting can
-   happily trash your host system. You should only ever run trusted
-   code with semihosting enabled.
+   happily trash your host system. Some semihosting calls (e.g.
+   ``SYS_READC``) can block execution indefinitely. You should only
+   ever run trusted code with semihosting enabled.
 
 Redirection
 ~~~~~~~~~~~
-- 
2.39.2



  parent reply	other threads:[~2023-11-15 20:57 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-15 20:55 [PATCH 00/10] random fixes for 8.2 (tests, plugins, docs, semihosting) Alex Bennée
2023-11-15 20:55 ` [PATCH 01/10] tests/docker: replace fedora-i386 with debian-i686 Alex Bennée
2023-11-15 20:55 ` [PATCH 02/10] .gitlab-ci.d/cirrus: Upgrade macOS to 13 (Ventura) Alex Bennée
2023-11-15 20:55 ` [PATCH 03/10] tests/docker: merge debian-native with debian-amd64 Alex Bennée
2023-11-15 20:55 ` [PATCH 04/10] plugins: fix win plugin tests on cross compile Alex Bennée
2023-11-15 20:55 ` [PATCH 05/10] tests/tcg: fixup Aarch64 semiconsole test Alex Bennée
2023-11-15 20:55 ` Alex Bennée [this message]
2023-11-15 20:55 ` [PATCH 07/10] hw/core: skip loading debug on all failures Alex Bennée
2023-11-15 21:11   ` Richard Henderson
2023-11-15 22:41   ` Philippe Mathieu-Daudé
2023-11-15 20:55 ` [PATCH 08/10] testing: move arm system tests into their own folder Alex Bennée
2023-11-15 21:12   ` Richard Henderson
2023-11-15 22:42   ` Philippe Mathieu-Daudé
2023-11-15 20:55 ` [PATCH 09/10] tests/tcg: enable arm softmmu tests Alex Bennée
2023-11-15 21:21   ` Richard Henderson
2023-11-15 20:55 ` [PATCH 10/10] tests/tcg: enable semiconsole test for Arm Alex Bennée

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