From d3df4de7eb095cc4334759a5e65bf3bfb4be04f1 Mon Sep 17 00:00:00 2001 From: Quentin Casasnovas Date: Thu, 16 Apr 2015 13:03:32 +0930 Subject: [PATCH] modpost: fix inverted logic in is_extable_fault_address(). As Guenter pointed out, we want to assert that extable_entry_size has been discovered and not the other way around. Moreover, this sanity check is only valid when we're not dealing with the first relocation in __ex_table, since we have not discovered the extable entry size at that point. This was leading to a divide-by-zero on some architectures and make the build fail. Signed-off-by: Quentin Casasnovas Reported-by: Guenter Roeck CC: Rusty Russell Signed-off-by: Rusty Russell --- scripts/mod/modpost.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 22dbc60..93bb87d 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1529,7 +1529,12 @@ static void find_extable_entry_size(const char* const sec, const Elf_Rela* r, } static inline bool is_extable_fault_address(Elf_Rela *r) { - if (!extable_entry_size == 0) + /* + * extable_entry_size is only discovered after we've handled the + * _second_ relocation in __ex_table, so only abort when we're not + * handling the first reloc and extable_entry_size is zero. + */ + if (r->r_offset && extable_entry_size == 0) fatal("extable_entry size hasn't been discovered!\n"); return ((r->r_offset == 0) || -- 2.7.4