commit dda014ba59331dee4f3b773a020e109932f4bd24 upstream.
The syscall instruction is used in Xen PV mode for doing hypercalls.
Allow syscall to be used in the kernel in case it is tagged with an
unwind hint for objtool.
This is part of XSA-466 / CVE-2024-53241.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ca3574bd653aba234a4b31955f2778947403be16 ]
Update module_put_and_exit to call kthread_exit instead of do_exit.
Change the name to reflect this change in functionality. All of the
users of module_put_and_exit are causing the current kthread to exit
so this change makes it clear what is happening. There is no
functional change.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bbda86e988d4c124e4cfa816291cbd583ae8bfb1 ]
The way the per task_struct exit_code is used by kernel threads is not
quite compatible how it is used by userspace applications. The low
byte of the userspace exit_code value encodes the exit signal. While
kthreads just use the value as an int holding ordinary kernel function
exit status like -EPERM.
Add kthread_exit to clearly separate the two kinds of uses.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Stable-dep-of: ca3574bd653a ("exit: Rename module_put_and_exit to module_put_and_kthread_exit")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
When dbf460087755 ("objtool/x86: Fixup frame-pointer vs rethunk")
was backported to some stable branches, the check for dest->embedded_insn
in is_special_call() was missed. The result is that the warning it
was intended to suppress still appears. For example on 6.1 (on kernels
before 6.1, the '-s' argument would instead be 'check'):
$ tools/objtool/objtool -s arch/x86/lib/retpoline.o
arch/x86/lib/retpoline.o: warning: objtool: srso_untrain_ret+0xd:
call without frame pointer save/setup
With this patch, the warning is correctly suppressed, and the
kernel still passes the normal Google kernel developer tests.
Signed-off-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
