[PATCH AUTOSEL 5.18 53/68] objtool: Mark __ubsan_handle_builtin_unreachable() as noreturn

From: Sasha Levin
Date: Tue Jun 07 2022 - 14:57:58 EST


From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

[ Upstream commit 385bd430c011a8cb8278e61c32d602d11e06f414 ]

fs/ntfs3/ntfs3.prelink.o: warning: objtool: ni_read_frame() falls through to next function ni_readpage_cmpr.cold()

That is in fact:

000000000000124a <ni_read_frame.cold>:
124a: 44 89 e0 mov %r12d,%eax
124d: 0f b6 55 98 movzbl -0x68(%rbp),%edx
1251: 48 c7 c7 00 00 00 00 mov $0x0,%rdi 1254: R_X86_64_32S .data+0x1380
1258: 48 89 c6 mov %rax,%rsi
125b: e8 00 00 00 00 call 1260 <ni_read_frame.cold+0x16> 125c: R_X86_64_PLT32 __ubsan_handle_shift_out_of_bounds-0x4
1260: 48 8d 7d cc lea -0x34(%rbp),%rdi
1264: e8 00 00 00 00 call 1269 <ni_read_frame.cold+0x1f> 1265: R_X86_64_PLT32 __tsan_read4-0x4
1269: 8b 45 cc mov -0x34(%rbp),%eax
126c: e9 00 00 00 00 jmp 1271 <ni_read_frame.cold+0x27> 126d: R_X86_64_PC32 .text+0x19109
1271: 48 8b 75 a0 mov -0x60(%rbp),%rsi
1275: 48 63 d0 movslq %eax,%rdx
1278: 48 c7 c7 00 00 00 00 mov $0x0,%rdi 127b: R_X86_64_32S .data+0x13a0
127f: 89 45 88 mov %eax,-0x78(%rbp)
1282: e8 00 00 00 00 call 1287 <ni_read_frame.cold+0x3d> 1283: R_X86_64_PLT32 __ubsan_handle_shift_out_of_bounds-0x4
1287: 8b 45 88 mov -0x78(%rbp),%eax
128a: e9 00 00 00 00 jmp 128f <ni_read_frame.cold+0x45> 128b: R_X86_64_PC32 .text+0x19098
128f: 48 c7 c7 00 00 00 00 mov $0x0,%rdi 1292: R_X86_64_32S .data+0x11f0
1296: e8 00 00 00 00 call 129b <ni_readpage_cmpr.cold> 1297: R_X86_64_PLT32 __ubsan_handle_builtin_unreachable-0x4

000000000000129b <ni_readpage_cmpr.cold>:

Tell objtool that __ubsan_handle_builtin_unreachable() is a noreturn.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20220502091514.GB479834@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/objtool/check.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ca5b74603008..a0b4a5874fce 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -184,7 +184,8 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"do_group_exit",
"stop_this_cpu",
"__invalid_creds",
- "cpu_startup_entry",
+ "cpu_startup_entry",
+ "__ubsan_handle_builtin_unreachable",
};

if (!func)
--
2.35.1