As Guenter pointed out, we were never really calculating the extable entry
size because the pointer arithmetic was simply wrong. We want to check
we're handling the second relocation in __ex_table to infer an entry size,
but we were using (void*) pointers instead of Elf_Rel[a]* ones.
This fixes the problem by moving that check in the caller (since we can
deal with different types of relocations) and add is_second_extable_reloc()
to make the whole thing more readable.
Signed-off-by: Quentin Casasnovas <quentin.casasnovas@xxxxxxxxxx>
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
CC: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
scripts/mod/modpost.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 93bb87d..fd94977 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1511,8 +1511,7 @@ static int is_executable_section(struct elf_info* elf, unsigned int section_inde
* to know the sizeof(struct exception_table_entry) for the target architecture.
*/
static unsigned int extable_entry_size = 0;
-static void find_extable_entry_size(const char* const sec, const Elf_Rela* r,
- const void* start, const void* cur)
+static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
{
/*
* If we're currently checking the second relocation within __ex_table,
@@ -1523,10 +1522,10 @@ static void find_extable_entry_size(const char* const sec, const Elf_Rela* r,
* seems to go with different sized types. Not pretty but better than
* hard-coding the size for every architecture..
*/
- if (!extable_entry_size && cur == start + 1 &&
- strcmp("__ex_table", sec) == 0)
+ if (!extable_entry_size)
extable_entry_size = r->r_offset * 2;
}
+
static inline bool is_extable_fault_address(Elf_Rela *r)
{
/*
@@ -1541,6 +1540,9 @@ static inline bool is_extable_fault_address(Elf_Rela *r)
(r->r_offset % extable_entry_size == 0));
}
+#define is_second_extable_reloc(Start, Cur, Sec) \
+ (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
+
static void report_extable_warnings(const char* modname, struct elf_info* elf,
const struct sectioncheck* const mismatch,
Elf_Rela* r, Elf_Sym* sym,
@@ -1769,7 +1771,8 @@ static void section_rela(const char *modname, struct elf_info *elf,
/* Skip special sections */
if (is_shndx_special(sym->st_shndx))
continue;
- find_extable_entry_size(fromsec, &r, start, rela);
+ if (is_second_extable_reloc(start, rela, fromsec))
+ find_extable_entry_size(fromsec, &r);
check_section_mismatch(modname, elf, &r, sym, fromsec);
}
}
@@ -1828,7 +1831,8 @@ static void section_rel(const char *modname, struct elf_info *elf,
/* Skip special sections */
if (is_shndx_special(sym->st_shndx))
continue;
- find_extable_entry_size(fromsec, &r, start, rel);
+ if (is_second_extable_reloc(start, rel, fromsec))
+ find_extable_entry_size(fromsec, &r);
check_section_mismatch(modname, elf, &r, sym, fromsec);
}
}
--
2.0.5
--
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