* tosec = .init.text | .exit.text | .init.data
* fromsec = .data
* atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one
+ *
+ * Pattern 3:
+ * Some symbols belong to init section but still it is ok to reference
+ * these from non-init sections as these symbols don't have any memory
+ * allocated for them and symbol address and value are same. So even
+ * if init section is freed, its ok to reference those symbols.
+ * For ex. symbols marking the init section boundaries.
+ * This pattern is identified by
+ * refsymname = __init_begin, _sinittext, _einittext
**/
static int secref_whitelist(const char *modname, const char *tosec,
- const char *fromsec, const char *atsym)
+ const char *fromsec, const char *atsym,
+ const char *refsymname)
{
int f1 = 1, f2 = 1;
const char **s;
"_ops",
"_probe",
"_probe_one",
+ "_console",
+ NULL
+ };
+
+ const char *pat3refsym[] = {
+ "__init_begin",
+ "_sinittext",
+ "_einittext",
NULL
};
if (f1 && f2)
return 1;
- /* Whitelist all references from .pci_fixup section if vmlinux */
+ /* Whitelist all references from .pci_fixup section if vmlinux
+ * Whitelist all refereces from .text.head to .init.data if vmlinux
+ * Whitelist all refereces from .text.head to .init.text if vmlinux
+ */
if (is_vmlinux(modname)) {
if ((strcmp(fromsec, ".pci_fixup") == 0) &&
(strcmp(tosec, ".init.text") == 0))
return 1;
+
+ if ((strcmp(fromsec, ".text.head") == 0) &&
+ ((strcmp(tosec, ".init.data") == 0) ||
+ (strcmp(tosec, ".init.text") == 0)))
+ return 1;
+
+ /* Check for pattern 3 */
+ for (s = pat3refsym; *s; s++)
+ if (strcmp(refsymname, *s) == 0)
+ return 1;
}
return 0;
}
return NULL;
}
+static inline int is_arm_mapping_symbol(const char *str)
+{
+ return str[0] == '$' && strchr("atd", str[1])
+ && (str[2] == '\0' || str[2] == '.');
+}
+
+/*
+ * If there's no name there, ignore it; likewise, ignore it if it's
+ * one of the magic symbols emitted used by current ARM tools.
+ *
+ * Otherwise if find_symbols_between() returns those symbols, they'll
+ * fail the whitelist tests and cause lots of false alarms ... fixable
+ * only by merging __exit and __init sections into __text, bloating
+ * the kernel (which is especially evil on embedded platforms).
+ */
+static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
+{
+ const char *name = elf->strtab + sym->st_name;
+
+ if (!name || !strlen(name))
+ return 0;
+ return !is_arm_mapping_symbol(name);
+}
+
/*
* Find symbols before or equal addr and after addr - in the section sec.
* If we find two symbols with equal offset prefer one with a valid name.
symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
if (strcmp(symsec, sec) != 0)
continue;
+ if (!is_valid_name(elf, sym))
+ continue;
if (sym->st_value <= addr) {
if ((addr - sym->st_value) < beforediff) {
beforediff = addr - sym->st_value;
*before = sym;
}
else if ((addr - sym->st_value) == beforediff) {
- /* equal offset, valid name? */
- const char *name = elf->strtab + sym->st_name;
- if (name && strlen(name))
- *before = sym;
+ *before = sym;
}
}
else
*after = sym;
}
else if ((sym->st_value - addr) == afterdiff) {
- /* equal offset, valid name? */
- const char *name = elf->strtab + sym->st_name;
- if (name && strlen(name))
- *after = sym;
+ *after = sym;
}
}
}
/* check whitelist - we may ignore it */
if (before &&
secref_whitelist(modname, secname, fromsec,
- elf->strtab + before->st_name))
+ elf->strtab + before->st_name, refsymname))
return;
if (before && after) {
".opd", /* see comment [OPD] at exit_section_ref_ok() */
".toc1", /* used by ppc64 */
".stab",
- ".rodata",
+ ".data.rel.ro", /* used by parisc64 */
".parainstructions",
".text.lock",
"__bug_table", /* used by powerpc for BUG() */
".eh_frame",
".debug",
".parainstructions",
+ ".rodata",
NULL
};
/* part of section name */
"__bug_table", /* used by powerpc for BUG() */
".exitcall.exit",
".eh_frame",
+ ".parainstructions",
".stab",
"__ex_table",
".fixup",