linux/arch
Linus Torvalds 291073a566 kvm: fix objtool relocation warning
The recent change to make objtool aware of more symbol relocation types
(commit 24ff652573: "objtool: Teach get_alt_entry() about more
relocation types") also added another check, and resulted in this
objtool warning when building kvm on x86:

    arch/x86/kvm/emulate.o: warning: objtool: __ex_table+0x4: don't know how to handle reloc symbol type: kvm_fastop_exception

The reason seems to be that kvm_fastop_exception() is marked as a global
symbol, which causes the relocation to ke kept around for objtool.  And
at the same time, the kvm_fastop_exception definition (which is done as
an inline asm statement) doesn't actually set the type of the global,
which then makes objtool unhappy.

The minimal fix is to just not mark kvm_fastop_exception as being a
global symbol.  It's only used in that one compilation unit anyway, so
it was always pointless.  That's how all the other local exception table
labels are done.

I'm not entirely happy about the kinds of games that the kvm code plays
with doing its own exception handling, and the fact that it confused
objtool is most definitely a symptom of the code being a bit too subtle
and ad-hoc.  But at least this trivial one-liner makes objtool no longer
upset about what is going on.

Fixes: 24ff652573 ("objtool: Teach get_alt_entry() about more relocation types")
Link: https://lore.kernel.org/lkml/CAHk-=wiZwq-0LknKhXN4M+T8jbxn_2i9mcKpO+OaBSSq_Eh7tg@mail.gmail.com/
Cc: Borislav Petkov <bp@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-10-03 13:34:19 -07:00
..
alpha alpha: enable GENERIC_PCI_IOMAP unconditionally 2021-09-19 10:37:00 -07:00
arc Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
arm entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume() 2021-09-22 10:24:01 -04:00
arm64 x86: 2021-09-27 13:58:23 -07:00
csky entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume() 2021-09-22 10:24:01 -04:00
h8300 Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
hexagon Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
ia64 Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
m68k m68k: Remove set_fs() 2021-09-24 13:35:07 +02:00
microblaze Microblaze patches for 5.15-rc1 2021-09-08 16:02:13 -07:00
mips Networking fixes for 5.15-rc4, including fixes from mac80211, netfilter 2021-09-30 14:28:05 -07:00
nds32 nds32/setup: remove unused memblock_region variable in setup_memory() 2021-09-08 18:45:53 -07:00
nios2 NIOS2: setup.c: drop unused variable 'dram_start' 2021-09-27 08:34:54 -05:00
openrisc Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
parisc parisc: Declare pci_iounmap() parisc version only when CONFIG_PCI enabled 2021-09-19 10:36:09 -07:00
powerpc entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume() 2021-09-22 10:24:01 -04:00
riscv Merge branch 'gcc-min-version-5.1' (make gcc-5.1 the minimum version) 2021-09-13 10:43:04 -07:00
s390 x86: 2021-09-27 13:58:23 -07:00
sh sh: pgtable-3level: fix cast to pointer from integer of different size 2021-09-24 16:13:35 -07:00
sparc sparc64: fix pci_iounmap() when CONFIG_PCI is not set 2021-09-20 10:56:32 -07:00
um This pull request contains the following changes for UML: 2021-09-09 13:45:26 -07:00
x86 kvm: fix objtool relocation warning 2021-10-03 13:34:19 -07:00
xtensa Tracing updates for 5.15: 2021-09-05 11:50:41 -07:00
.gitignore
Kconfig Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00