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author | Sami Tolvanen <samitolvanen@google.com> | 2018-10-24 01:15:35 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 21:47:01 +0300 |
commit | b6293e6c9000c0f4ac4237801b8d4f446c764a6e (patch) | |
tree | 3e30dd2f8caf2d209ea7486fa7127c55569e788b | |
parent | 1b63e37679cb38e2e69e09e722c57ac80d42051c (diff) | |
download | linux-b6293e6c9000c0f4ac4237801b8d4f446c764a6e.tar.xz |
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:$x.0
This change adds a call to is_valid_name to find_elf_symbol, similarly
to how it's already used in find_elf_symbol2.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | scripts/mod/modpost.c | 50 |
1 files changed, 26 insertions, 24 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 5a5b3780456f..5a77efd39b3f 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1204,6 +1204,30 @@ static int secref_whitelist(const struct sectioncheck *mismatch, return 1; } +static inline int is_arm_mapping_symbol(const char *str) +{ + return str[0] == '$' && 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 @@ -1229,6 +1253,8 @@ 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 */ @@ -1247,30 +1273,6 @@ 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. |