fridtjof/qemu-cr16
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

kvm: Fix kvm_vm_ioctl() and kvm_device_ioctl() return value

Browse source 
These functions wrap ioctl().  When ioctl() fails, it sets @errno.
The wrappers then return that @errno negated.

Except they call accel_ioctl_end() between calling ioctl() and reading
@errno.  accel_ioctl_end() can clobber @errno, e.g. when a futex()
system call fails.  Seems unlikely, but it's a bug all the same.

Fix by retrieving @errno before calling accel_ioctl_end().

Fixes: a27dd2de68 (KVM: keep track of running ioctls)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20251128152050.3417834-1-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2025-11-28 16:20:50 +01:00
parent c1116b1d73
commit 88be119fb1
1 changed files with 2 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

4
accel/kvm/kvm-all.c
View file

@ -3373,10 +3373,10 @@ int kvm_vm_ioctl(KVMState *s, unsigned long type, ...)
trace_kvm_vm_ioctl(type, arg);
accel_ioctl_begin();
ret = ioctl(s->vmfd, type, arg);
accel_ioctl_end();
if (ret == -1) {
ret = -errno;
}
accel_ioctl_end();
return ret;
}
@ -3413,10 +3413,10 @@ int kvm_device_ioctl(int fd, unsigned long type, ...)
trace_kvm_device_ioctl(fd, type, arg);
accel_ioctl_begin();
ret = ioctl(fd, type, arg);
accel_ioctl_end();
if (ret == -1) {
ret = -errno;
}
accel_ioctl_end();
return ret;
}