4.9-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 5818c683a619c534c113e1f66d24f636defc29bc ]
If an ARM mapping symbol shares an address with a valid symbol, find_elf_symbol can currently return the mapping symbol instead, as the symbol is not validated. This can result in confusing warnings:
WARNING: vmlinux.o(.text+0x18f4028): Section mismatch in reference from the function set_reset_devices() to the variable .init.text:$x.0
This change adds a call to is_valid_name to find_elf_symbol, similarly to how it's already used in find_elf_symbol2.
Signed-off-by: Sami Tolvanen samitolvanen@google.com Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/mod/modpost.c | 50 ++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 24 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 88b3dc19bbae..fdf5bbfd00cd 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1198,6 +1198,30 @@ static int secref_whitelist(const struct sectioncheck *mismatch, return 1; }
+static inline int is_arm_mapping_symbol(const char *str) +{ + return str[0] == '$' && strchr("axtd", 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 symbol based on relocation record info. * In some cases the symbol supplied is a valid symbol so @@ -1223,6 +1247,8 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, continue; if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) continue; + if (!is_valid_name(elf, sym)) + continue; if (sym->st_value == addr) return sym; /* Find a symbol nearby - addr are maybe negative */ @@ -1241,30 +1267,6 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr, return NULL; }
-static inline int is_arm_mapping_symbol(const char *str) -{ - return str[0] == '$' && strchr("axtd", 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.