linux/arch/x86/hyperv
Guilherme G. Piccoli 611d4c716d x86/hyperv: Mark hv_ghcb_terminate() as noreturn
Annotate the function prototype and definition as noreturn to prevent
objtool warnings like:

vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction

Also, as per Josh's suggestion, add it to the global_noreturns list.
As a comparison, an objdump output without the annotation:

[...]
1b63:  mov    $0x1,%esi
1b68:  xor    %edi,%edi
1b6a:  callq  ffffffff8102f680 <hv_ghcb_terminate>
1b6f:  jmpq   ffffffff82f217ec <hyperv_init+0x9c> # unreachable
1b74:  cmpq   $0xffffffffffffffff,-0x702a24(%rip)
[...]

Now, after adding the __noreturn to the function prototype:

[...]
17df:  callq  ffffffff8102f6d0 <hv_ghcb_negotiate_protocol>
17e4:  test   %al,%al
17e6:  je     ffffffff82f21bb9 <hyperv_init+0x469>
[...]  <many insns>
1bb9:  mov    $0x1,%esi
1bbe:  xor    %edi,%edi
1bc0:  callq  ffffffff8102f680 <hv_ghcb_terminate>
1bc5:  nopw   %cs:0x0(%rax,%rax,1) # end of function

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/32453a703dfcf0d007b473c9acbf70718222b74b.1681342859.git.jpoimboe@kernel.org
2023-04-14 17:31:28 +02:00
..
hv_apic.c KVM: x86: lapic: Rename [GET/SET]_APIC_DEST_FIELD to [GET/SET]_XAPIC_DEST_FIELD 2022-06-24 12:44:34 -04:00
hv_init.c x86/hyperv: Remove unregister syscore call from Hyper-V cleanup 2022-11-29 17:55:29 +00:00
hv_proc.c drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status 2021-04-21 09:49:19 +00:00
hv_spinlock.c x86/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_wait 2021-03-24 11:31:04 +00:00
irqdomain.c genirq: Return a const cpumask from irq_data_get_affinity_mask 2022-07-07 09:38:04 +01:00
ivm.c x86/hyperv: Mark hv_ghcb_terminate() as noreturn 2023-04-14 17:31:28 +02:00
Makefile x86/hyperv: Add new hvcall guest address host visibility support 2021-10-28 11:21:33 +00:00
mmu.c x86/hyperv: Properly deal with empty cpumasks in hyperv_flush_tlb_multi() 2022-01-10 11:50:20 +00:00
nested.c drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status 2021-04-21 09:49:19 +00:00