get_stubs_size assumes that there must always be at least one patchable
function entry, which is not always the case (modules that export data
but no code), otherwise it returns -ENOEXEC and thus the section header
sh_size is set to that value. During module_memory_alloc() the size is
passed to execmem_alloc() after being page-aligned and thus set to zero
which will cause it to fail the allocation (and thus module loading) as
__vmalloc_node_range() checks for zero-sized allocs and returns null:
[ 115.466896] module_64: cast_common: doesn't contain
__patchable_function_entries.
[ 115.469189] ------------[ cut here ]------------
[ 115.469496] WARNING: CPU: 0 PID: 274 at mm/vmalloc.c:3778
__vmalloc_node_range_noprof+0x8b4/0x8f0
...
[ 115.478574] ---[ end trace 0000000000000000 ]---
[ 115.479545] execmem: unable to allocate memory
Fix this by removing the check completely, since it is anyway not
helpful to propagate this as an error upwards.
Fixes: eec37961a56a ("powerpc64/ftrace: Move ftrace sequence out of line")
Signed-off-by: Anthony Iliopoulos <ail...@suse.com>
---
arch/powerpc/kernel/module_64.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 34a5aec4908f..126bf3b06ab7 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -258,10 +258,6 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
break;
}
}
- if (i == hdr->e_shnum) {
- pr_err("%s: doesn't contain __patchable_function_entries.\n",
me->name);
- return -ENOEXEC;
- }
#endif
pr_debug("Looks like a total of %lu stubs, max\n", relocs);
--
2.47.0
