From 9142be9e6443fd641ca37f820efe00d9cd890eb1 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 25 Jun 2024 23:02:00 -0700 Subject: x86/syscall: Mark exit[_group] syscall handlers __noreturn The direct-call syscall dispatch function doesn't know that the exit() and exit_group() syscall handlers don't return, so the call sites aren't optimized accordingly. Fix that by marking the exit syscall declarations __noreturn. Fixes the following warnings: vmlinux.o: warning: objtool: x64_sys_call+0x2804: __x64_sys_exit() is missing a __noreturn annotation vmlinux.o: warning: objtool: ia32_sys_call+0x29b6: __ia32_sys_exit_group() is missing a __noreturn annotation Fixes: 1e3ad78334a6 ("x86/syscall: Don't force use of indirect calls for system calls") Closes: https://lkml.kernel.org/lkml/6dba9b32-db2c-4e6d-9500-7a08852f17a3@paulmck-laptop Reported-by: Paul E. McKenney Signed-off-by: Josh Poimboeuf Signed-off-by: Borislav Petkov (AMD) Tested-by: Paul E. McKenney Link: https://lore.kernel.org/r/5d8882bc077d8eadcc7fd1740b56dfb781f12288.1719381528.git.jpoimboe@kernel.org --- tools/objtool/noreturns.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'tools/objtool') diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h index 7ebf29c91184..1e8141ef1b15 100644 --- a/tools/objtool/noreturns.h +++ b/tools/objtool/noreturns.h @@ -7,12 +7,16 @@ * Yes, this is unfortunate. A better solution is in the works. */ NORETURN(__fortify_panic) +NORETURN(__ia32_sys_exit) +NORETURN(__ia32_sys_exit_group) NORETURN(__kunit_abort) NORETURN(__module_put_and_kthread_exit) NORETURN(__reiserfs_panic) NORETURN(__stack_chk_fail) NORETURN(__tdx_hypercall_failed) NORETURN(__ubsan_handle_builtin_unreachable) +NORETURN(__x64_sys_exit) +NORETURN(__x64_sys_exit_group) NORETURN(arch_cpu_idle_dead) NORETURN(bch2_trans_in_restart_error) NORETURN(bch2_trans_restart_error) -- cgit v1.2.3