diff options
| -rw-r--r-- | scripts/mod/modpost.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index de0a9ee..663b1ef 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -452,6 +452,89 @@ static char *get_modinfo(void *modinfo, unsigned long modinfo_len, } /** + * Test if string s ends in string sub + * return 0 if match + **/ +static int strrcmp(const char *s, const char *sub) +{ + int slen, sublen; + + if (!s || !sub) + return 1; + + slen = strlen(s); + sublen = strlen(sub); + + if ((slen == 0) || (sublen == 0)) + return 1; + + if (sublen > slen) + return 1; + + return memcmp(s + slen - sublen, sub, sublen); +} + +/** + * Whitelist to allow certain references to pass with no warning. + * Pattern 1: + * If a module parameter is declared __initdata and permissions=0 + * then this is legal despite the warning generated. + * We cannot see value of permissions here, so just ignore + * this pattern. + * The pattern is identified by: + * tosec = .init.data + * fromsec = .data + * atsym =__param* + * + * Pattern 2: + * Many drivers utilise a *_driver container with references to + * add, remove, probe functions etc. + * These functions may often be marked __init and we do not want to + * warn here. + * the pattern is identified by: + * tosec = .init.text | .exit.text + * fromsec = .data + * atsym = *_driver, *_ops, *_probe, *probe_one + **/ +static int secref_whitelist(const char *tosec, const char *fromsec, + const char *atsym) +{ + int f1 = 1, f2 = 1; + const char **s; + const char *pat2sym[] = { + "_driver", + "_ops", + "_probe", + "_probe_one", + NULL + }; + + /* Check for pattern 1 */ + if (strcmp(tosec, ".init.data") != 0) + f1 = 0; + if (strcmp(fromsec, ".data") != 0) + f1 = 0; + if (strncmp(atsym, "__param", strlen("__param")) != 0) + f1 = 0; + + if (f1) + return f1; + + /* Check for pattern 2 */ + if ((strcmp(tosec, ".init.text") != 0) && + (strcmp(tosec, ".exit.text") != 0)) + f2 = 0; + if (strcmp(fromsec, ".data") != 0) + f2 = 0; + + for (s = pat2sym; *s; s++) + if (strrcmp(atsym, *s) == 0) + f1 = 1; + + return f1 && f2; +} + +/** * Find symbol based on relocation record info. * In some cases the symbol supplied is a valid symbol so * return refsym. If st_name != 0 we assume this is a valid symbol. @@ -518,6 +601,7 @@ static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, /** * Print a warning about a section mismatch. * Try to find symbols near it so user can find it. + * Check whitelist before warning - it may be a false positive. **/ static void warn_sec_mismatch(const char *modname, const char *fromsec, struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) @@ -536,6 +620,11 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec, refsym = find_elf_symbol(elf, r.r_addend, sym); if (refsym && strlen(elf->strtab + refsym->st_name)) refsymname = elf->strtab + refsym->st_name; + + /* check whitelist - we may ignore it */ + if (before && + secref_whitelist(secname, fromsec, elf->strtab + before->st_name)) + return; if (before && after) { warn("%s - Section mismatch: reference to %s:%s from %s " |
