All of lore.kernel.org
 help / color / mirror / Atom feed
From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: Warner Losh <imp@bsdimp.com>
Subject: [PULL 12/15] common-user: Adjust system call return on FreeBSD
Date: Mon, 20 Dec 2021 12:24:57 -0800	[thread overview]
Message-ID: <20211220202500.111897-13-richard.henderson@linaro.org> (raw)
In-Reply-To: <20211220202500.111897-1-richard.henderson@linaro.org>

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.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 common-user/host/aarch64/safe-syscall.inc.S | 14 +++++++++++++-
 common-user/host/arm/safe-syscall.inc.S     |  9 +++++++++
 common-user/host/i386/safe-syscall.inc.S    | 11 +++++++++++
 common-user/host/x86_64/safe-syscall.inc.S  | 11 +++++++++++
 4 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/common-user/host/aarch64/safe-syscall.inc.S b/common-user/host/aarch64/safe-syscall.inc.S
index 73a04b73b3..b8fd5b553e 100644
--- a/common-user/host/aarch64/safe-syscall.inc.S
+++ b/common-user/host/aarch64/safe-syscall.inc.S
@@ -60,17 +60,29 @@ safe_syscall_start:
         cbnz    w10, 2f
         svc     0x0
 safe_syscall_end:
+
         /* code path for having successfully executed the syscall */
+#if defined(__linux__)
+        /* Linux kernel returns (small) negative errno. */
         cmp     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
 
+#if defined(__linux__)
         /* code path setting errno */
 0:      neg     w0, w0
         b       safe_syscall_set_errno_tail
+#endif
 
         /* code path when we didn't execute the syscall */
 2:      mov     w0, #QEMU_ERESTARTSYS
-        b       safe_syscall_set_errno_tail
+1:      b       safe_syscall_set_errno_tail
+
         .cfi_endproc
         .size   safe_syscall_base, .-safe_syscall_base
diff --git a/common-user/host/arm/safe-syscall.inc.S b/common-user/host/arm/safe-syscall.inc.S
index 66176a902c..bbfb89634e 100644
--- a/common-user/host/arm/safe-syscall.inc.S
+++ b/common-user/host/arm/safe-syscall.inc.S
@@ -74,10 +74,19 @@ safe_syscall_start:
         bne     2f
         swi     0
 safe_syscall_end:
+
         /* code path for having successfully executed the syscall */
+#if defined(__linux__)
+        /* Linux kernel returns (small) negative errno. */
         cmp     r0, #-4096
         neghi   r0, r0
         bhi     1f
+#elif defined(__FreeBSD__)
+        /* FreeBSD kernel returns positive errno and C bit set. */
+        bcs     1f
+#else
+#error "unsupported os"
+#endif
         pop     { r4, r5, r6, r7, r8, pc }
 
         /* code path when we didn't execute the syscall */
diff --git a/common-user/host/i386/safe-syscall.inc.S b/common-user/host/i386/safe-syscall.inc.S
index aced8c5141..baf5400a29 100644
--- a/common-user/host/i386/safe-syscall.inc.S
+++ b/common-user/host/i386/safe-syscall.inc.S
@@ -71,9 +71,18 @@ safe_syscall_start:
         mov     8+16(%esp), %eax        /* syscall number */
         int     $0x80
 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. */
+        jc      1f
+#else
+#error "unsupported os"
+#endif
         pop     %ebx
         .cfi_remember_state
         .cfi_adjust_cfa_offset -4
@@ -90,8 +99,10 @@ safe_syscall_end:
         ret
         .cfi_restore_state
 
+#if defined(__linux__)
 0:      neg     %eax
         jmp     1f
+#endif
 
         /* code path when we didn't execute the syscall */
 2:      mov     $QEMU_ERESTARTSYS, %eax
diff --git a/common-user/host/x86_64/safe-syscall.inc.S b/common-user/host/x86_64/safe-syscall.inc.S
index 84fed206f9..a20927a783 100644
--- a/common-user/host/x86_64/safe-syscall.inc.S
+++ b/common-user/host/x86_64/safe-syscall.inc.S
@@ -68,9 +68,18 @@ safe_syscall_start:
         jnz     2f
         syscall
 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. */
+        jc      1f
+#else
+#error "unsupported os"
+#endif
         pop     %rbp
         .cfi_remember_state
         .cfi_def_cfa_offset 8
@@ -78,8 +87,10 @@ safe_syscall_end:
         ret
         .cfi_restore_state
 
+#if defined(__linux__)
 0:      neg     %eax
         jmp     1f
+#endif
 
         /* code path when we didn't execute the syscall */
 2:      mov     $QEMU_ERESTARTSYS, %eax
-- 
2.25.1



  parent reply	other threads:[~2021-12-20 20:34 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-20 20:24 [PULL 00/15] *-user: simplify safe signal handling Richard Henderson
2021-12-20 20:24 ` [PULL 01/15] linux-user: Untabify all safe-syscall.inc.S Richard Henderson
2021-12-20 20:24 ` [PULL 02/15] linux-user: Move syscall error detection into safe_syscall_base Richard Henderson
2022-01-04 13:51   ` Laurent Vivier
2022-01-04 18:12     ` Richard Henderson
2021-12-20 20:24 ` [PULL 03/15] linux-user/host/mips: Add safe-syscall.inc.S Richard Henderson
2021-12-20 20:24 ` [PULL 04/15] linux-user/host/sparc64: " Richard Henderson
2021-12-20 20:24 ` [PULL 05/15] linux-user: Remove HAVE_SAFE_SYSCALL and hostdep.h Richard Henderson
2021-12-20 20:24 ` [PULL 06/15] linux-user: Rename TARGET_ERESTARTSYS to QEMU_ERESTARTSYS Richard Henderson
2021-12-20 20:24 ` [PULL 07/15] bsd-user: " Richard Henderson
2021-12-20 20:24 ` [PULL 08/15] linux-user: Rename TARGET_QEMU_ESIGRETURN to QEMU_ESIGRETURN Richard Henderson
2021-12-20 20:24 ` [PULL 09/15] linux-user: Create special-errno.h Richard Henderson
2021-12-20 20:24 ` [PULL 10/15] bsd-user: " Richard Henderson
2021-12-20 20:24 ` [PULL 11/15] common-user: Move safe-syscall.* from linux-user Richard Henderson
2021-12-20 20:24 ` Richard Henderson [this message]
2021-12-20 20:24 ` [PULL 13/15] linux-user: Move thunk.c from top-level Richard Henderson
2021-12-20 20:24 ` [PULL 14/15] meson: Move linux_user_ss to linux-user/ Richard Henderson
2021-12-20 20:25 ` [PULL 15/15] meson: Move bsd_user_ss to bsd-user/ Richard Henderson
2021-12-20 23:54 ` [PULL 00/15] *-user: simplify safe signal handling Richard Henderson

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=20211220202500.111897-13-richard.henderson@linaro.org \
    --to=richard.henderson@linaro.org \
    --cc=imp@bsdimp.com \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.