| From 50451b7c062eb77d9717c4070bb97cdf47645ba9 Mon Sep 17 00:00:00 2001 |
| From: Sami Tolvanen <samitolvanen@google.com> |
| Date: Tue, 23 Oct 2018 15:15:35 -0700 |
| Subject: modpost: validate symbol names also in find_elf_symbol |
| |
| [ 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:$x.0 |
| |
| This change adds a call to is_valid_name to find_elf_symbol, similarly |
| to how it's already used in find_elf_symbol2. |
| |
| Signed-off-by: Sami Tolvanen <samitolvanen@google.com> |
| Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| scripts/mod/modpost.c | 50 ++++++++++++++++++++++--------------------- |
| 1 file changed, 26 insertions(+), 24 deletions(-) |
| |
| diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c |
| index 18bc8738e989..e36a673833ae 100644 |
| --- a/scripts/mod/modpost.c |
| +++ b/scripts/mod/modpost.c |
| @@ -1215,6 +1215,30 @@ static int secref_whitelist(const struct sectioncheck *mismatch, |
| return 1; |
| } |
| |
| +static inline int is_arm_mapping_symbol(const char *str) |
| +{ |
| + return str[0] == '$' && 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 |
| @@ -1240,6 +1264,8 @@ 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 */ |
| @@ -1258,30 +1284,6 @@ 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. |
| -- |
| 2.19.1 |
| |