objtool ports introduced in v4.9.106 were not totally complete. Therefore
they resulted in issues like:
module: overflow in relocation type 10 val XXXXXXXXXXX
‘usbcore’ likely not compiled with -mcmodel=kernel
module: overflow in relocation type 10 val XXXXXXXXXXX
‘scsi_mod’ likely not compiled with -mcmodel=kernel
Missing part was the complete backport of commit e390f9a.
Original notes by Josh Poimboeuf:
The '__unreachable' and '__func_stack_frame_non_standard' sections are
only used at compile time. They're discarded for vmlinux but they
should also be discarded for modules.
Since this is a recurring pattern, prefix the section names with
".discard.". It's a nice convention and vmlinux.lds.h already discards
such sections.
Also remove the 'a' (allocatable) flag from the __unreachable section
since it doesn't make sense for a discarded section.
Signed-off-by: Philip Müller <philm@xxxxxxxxxxx>
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead
ends")
Link: https://gitlab.manjaro.org/packages/core/linux49/issues/2
diff -Npur linux-4.9.106.orig/arch/x86/kernel/vmlinux.lds.S linux-4.9.106/arch/x86/kernel/vmlinux.lds.S
--- linux-4.9.106.orig/arch/x86/kernel/vmlinux.lds.S 2018-06-09 12:43:04.238314000 +0200
+++ linux-4.9.106/arch/x86/kernel/vmlinux.lds.S 2018-06-09 12:44:39.034361441 +0200
@@ -352,8 +352,6 @@ SECTIONS
DISCARDS
/DISCARD/ : {
*(.eh_frame)
- *(__func_stack_frame_non_standard)
- *(__unreachable)
}
}
diff -Npur linux-4.9.106.orig/include/linux/compiler-gcc.h linux-4.9.106/include/linux/compiler-gcc.h
--- linux-4.9.106.orig/include/linux/compiler-gcc.h 2018-06-09 12:43:05.058337000 +0200
+++ linux-4.9.106/include/linux/compiler-gcc.h 2018-06-09 12:45:35.779367605 +0200
@@ -206,7 +206,7 @@
#ifdef CONFIG_STACK_VALIDATION
#define annotate_unreachable() ({ \
asm("1:\t\n" \
- ".pushsection __unreachable, \"a\"\t\n" \
+ ".pushsection .discard.unreachable\t\n" \
".long 1b\t\n" \
".popsection\t\n"); \
})
