From: Borislav Petkov <bp@suse.de>
Date: Wed, 24 Aug 2022 17:13:26 +0200
Subject: x86/sev: Mark snp_abort() noreturn
Git-commit: c93c296fff6b369a7115916145047c8a3db6e27f
Patch-mainline: v6.0-rc3
References: jsc#PED-7167
Mark both the function prototype and definition as noreturn in order to
prevent the compiler from doing transformations which confuse objtool
like so:
vmlinux.o: warning: objtool: sme_enable+0x71: unreachable instruction
This triggers with gcc-12.
Add it and sev_es_terminate() to the objtool noreturn tracking array
too. Sort it while at it.
Suggested-by: Michael Matz <matz@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220824152420.20547-1-bp@alien8.de
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
arch/x86/include/asm/sev.h | 2 +-
arch/x86/kernel/sev.c | 2 +-
tools/objtool/check.c | 20 +++++++++++---------
3 files changed, 13 insertions(+), 11 deletions(-)
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -194,7 +194,7 @@ void snp_set_memory_shared(unsigned long
void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
-void snp_abort(void);
+void __init __noreturn snp_abort(void);
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -2112,7 +2112,7 @@ bool __init snp_init(struct boot_params
return true;
}
-void __init snp_abort(void)
+void __init __noreturn snp_abort(void)
{
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
}
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -164,22 +164,24 @@ static bool __dead_end_function(struct o
* attribute isn't provided in ELF data.
*/
static const char * const global_noreturns[] = {
+ "__module_put_and_exit",
+ "__reiserfs_panic",
"__stack_chk_fail",
- "panic",
+ "complete_and_exit",
+ "cpu_bringup_and_idle",
"do_exit",
"do_task_dead",
- "make_task_dead",
- "__module_put_and_exit",
- "complete_and_exit",
- "__reiserfs_panic",
- "lbug_with_loc",
"fortify_panic",
- "usercopy_abort",
+ "kunit_try_catch_throw",
+ "lbug_with_loc",
"machine_real_restart",
+ "make_task_dead",
+ "panic",
"rewind_stack_and_make_dead",
- "kunit_try_catch_throw",
+ "sev_es_terminate",
+ "snp_abort",
+ "usercopy_abort",
"xen_start_kernel",
- "cpu_bringup_and_idle",
};
if (!func)