From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: laurent@vivier.eu, imp@bsdimp.com
Subject: [PATCH v4 8/9] common-user: Adjust system call return on FreeBSD
Date: Tue, 16 Nov 2021 12:02:55 +0100 [thread overview]
Message-ID: <20211116110256.365484-9-richard.henderson@linaro.org> (raw)
In-Reply-To: <20211116110256.365484-1-richard.henderson@linaro.org>
From: Warner Losh <imp@bsdimp.com>
FreeBSD system calls return positive errno. On the 4 hosts for
which we have support, error is indicated by the C bit set or clear.
Signed-off-by: Warner Losh <imp@bsdimp.com>
[rth: Rebase on new safe_syscall_base api; add #error check.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
common-user/host/aarch64/safe-syscall.inc.S | 12 +++++++++++-
common-user/host/arm/safe-syscall.inc.S | 11 +++++++++++
common-user/host/i386/safe-syscall.inc.S | 10 ++++++++++
common-user/host/x86_64/safe-syscall.inc.S | 10 ++++++++++
4 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/common-user/host/aarch64/safe-syscall.inc.S b/common-user/host/aarch64/safe-syscall.inc.S
index 95c60d8609..d3f065cdef 100644
--- a/common-user/host/aarch64/safe-syscall.inc.S
+++ b/common-user/host/aarch64/safe-syscall.inc.S
@@ -65,12 +65,22 @@ safe_syscall_start:
safe_syscall_end:
/* code path for having successfully executed the syscall */
- cmn x0, #4095
+#if defined(__linux__)
+ /* Linux kernel returns (small) negative errno. */
+ cmn x0, #4096
+ b.hi 0f
+#elif defined(__FreeBSD__)
+ /* FreeBSD kernel returns positive errno and C bit set. */
b.cs 1f
+#else
+#error "unsupported os"
+#endif
ret
/* code path setting errno */
+#ifdef __linux__
0: neg w0, w0 /* create positive errno */
+#endif
1: str w0, [x11] /* store errno */
mov x0, #-1
ret
diff --git a/common-user/host/arm/safe-syscall.inc.S b/common-user/host/arm/safe-syscall.inc.S
index 17839c6486..328299021d 100644
--- a/common-user/host/arm/safe-syscall.inc.S
+++ b/common-user/host/arm/safe-syscall.inc.S
@@ -82,12 +82,23 @@ safe_syscall_start:
safe_syscall_end:
/* code path for having successfully executed the syscall */
+#if defined(__linux__)
+ /* Linux kernel returns (small) negative errno. */
cmp r0, #-4096
bhi 0f
+#elif defined(__FreeBSD__)
+ /* FreeBSD kernel returns positive errno and C bit set. */
+ bcs 1f
+#else
+#error "unsupported os"
+#endif
+
9: pop { r4, r5, r6, r7, r8, r9, r10, pc }
/* code path setting errno */
+#ifdef __linux__
0: neg r0, r0 /* create positive errno */
+#endif
1: str r0, [r9] /* store errno */
mov r0, #-1
b 9b
diff --git a/common-user/host/i386/safe-syscall.inc.S b/common-user/host/i386/safe-syscall.inc.S
index ad89521783..a9382f777e 100644
--- a/common-user/host/i386/safe-syscall.inc.S
+++ b/common-user/host/i386/safe-syscall.inc.S
@@ -76,8 +76,16 @@ safe_syscall_start:
safe_syscall_end:
/* code path for having successfully executed the syscall */
+#if defined(__linux__)
+ /* Linux kernel returns (small) negative errno. */
cmp $-4095, %eax
jae 0f
+#elif defined(__FreeBSD__)
+ /* FreeBSD kernel returns positive errno and C bit set. */
+ jcs 1f
+#else
+#error "unsupported os"
+#endif
9: pop %ebx
.cfi_remember_state
@@ -97,7 +105,9 @@ safe_syscall_end:
.cfi_restore_state
/* code path setting errno */
+#ifdef __linux__
0: neg %eax /* create positive errno */
+#endif
1: mov 8+16(%esp), %ebx /* load errno pointer */
mov %eax, (%ebx) /* store errno */
mov $-1, %eax
diff --git a/common-user/host/x86_64/safe-syscall.inc.S b/common-user/host/x86_64/safe-syscall.inc.S
index 9a0c4c93b4..36b7efe2ca 100644
--- a/common-user/host/x86_64/safe-syscall.inc.S
+++ b/common-user/host/x86_64/safe-syscall.inc.S
@@ -75,8 +75,16 @@ safe_syscall_start:
safe_syscall_end:
/* code path for having successfully executed the syscall */
+#if defined(__linux__)
+ /* Linux kernel returns (small) negative errno. */
cmp $-4095, %rax
jae 0f
+#elif defined(__FreeBSD__)
+ /* FreeBSD kernel returns positive errno and C bit set. */
+ jcs 1f
+#else
+#error "unsupported os"
+#endif
9: pop %rbp
.cfi_remember_state
@@ -86,7 +94,9 @@ safe_syscall_end:
.cfi_restore_state
/* code path setting errno */
+#ifdef __linux__
0: neg %eax /* create positive errno */
+#endif
1: mov %eax, (%rbp) /* store errno */
mov $-1, %rax
jmp 9b
--
2.25.1
next prev parent reply other threads:[~2021-11-16 11:07 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-16 11:02 [PATCH v4 0/9] linux-user: simplify safe signal handling Richard Henderson
2021-11-16 11:02 ` [PATCH v4 1/9] linux-user: Add host_signal_set_pc to set pc in mcontext Richard Henderson
2021-11-16 11:02 ` [PATCH v4 2/9] linux-user/signal.c: Create a common rewind_if_in_safe_syscall Richard Henderson
2021-11-16 11:02 ` [PATCH v4 3/9] linux-user/safe-syscall.inc.S: Move to common-user Richard Henderson
2021-11-16 21:03 ` Warner Losh
2021-11-17 8:11 ` Philippe Mathieu-Daudé
2021-11-17 12:49 ` Richard Henderson
2021-11-17 16:09 ` Warner Losh
2021-11-17 16:20 ` Philippe Mathieu-Daudé
2021-11-16 11:02 ` [PATCH v4 4/9] common-user: Move syscall error detection into safe_syscall_base Richard Henderson
2021-11-16 11:02 ` [PATCH v4 5/9] common-user/host/mips: Add safe-syscall.inc.S Richard Henderson
2021-11-16 11:02 ` [PATCH v4 6/9] common-user/host/sparc64: " Richard Henderson
2021-11-16 11:02 ` [PATCH v4 7/9] linux-user: Remove HAVE_SAFE_SYSCALL and hostdep.h Richard Henderson
2021-11-17 8:22 ` Philippe Mathieu-Daudé
2021-11-17 15:58 ` Warner Losh
2021-11-16 11:02 ` Richard Henderson [this message]
2021-11-16 20:58 ` [PATCH v4 8/9] common-user: Adjust system call return on FreeBSD Warner Losh
2021-11-16 21:43 ` Richard Henderson
2021-11-17 8:23 ` Philippe Mathieu-Daudé
2021-11-17 8:32 ` Richard Henderson
2021-11-17 8:38 ` Philippe Mathieu-Daudé
2021-11-16 11:02 ` [PATCH v4 9/9] common-user: Move safe-syscall.* from *-user Richard Henderson
2021-11-16 21:10 ` [PATCH v4 0/9] linux-user: simplify safe signal handling Warner Losh
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=20211116110256.365484-9-richard.henderson@linaro.org \
--to=richard.henderson@linaro.org \
--cc=imp@bsdimp.com \
--cc=laurent@vivier.eu \
--cc=qemu-devel@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).