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| author | Guilherme G. Piccoli <gpiccoli@igalia.com> | 2023-04-12 16:49:41 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-04-14 17:31:28 +0200 |
| commit | 611d4c716db0141cfc436994dc5aff1d69c924ad (patch) | |
| tree | e9ac00045ab1e399e41c4298bb66fa76a1b7279d /arch | |
| parent | 6e36a56a5f617262c0e8ae7e961487361c720b9e (diff) | |
| download | lwn-611d4c716db0141cfc436994dc5aff1d69c924ad.tar.gz lwn-611d4c716db0141cfc436994dc5aff1d69c924ad.zip | |
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
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/hyperv/ivm.c | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/mshyperv.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c index 1dbcbd9da74d..4f79dc76042d 100644 --- a/arch/x86/hyperv/ivm.c +++ b/arch/x86/hyperv/ivm.c @@ -127,7 +127,7 @@ static enum es_result hv_ghcb_hv_call(struct ghcb *ghcb, u64 exit_code, return ES_OK; } -void hv_ghcb_terminate(unsigned int set, unsigned int reason) +void __noreturn hv_ghcb_terminate(unsigned int set, unsigned int reason) { u64 val = GHCB_MSR_TERM_REQ; diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 4c4c0ec3b62e..09c26e658bcc 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -212,7 +212,7 @@ int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible); void hv_ghcb_msr_write(u64 msr, u64 value); void hv_ghcb_msr_read(u64 msr, u64 *value); bool hv_ghcb_negotiate_protocol(void); -void hv_ghcb_terminate(unsigned int set, unsigned int reason); +void __noreturn hv_ghcb_terminate(unsigned int set, unsigned int reason); #else static inline void hv_ghcb_msr_write(u64 msr, u64 value) {} static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {} |