| Message ID | 20230707160051.2305-2-palmer@rivosinc.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | [v2] module: Ignore RISC-V mapping symbols too | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/tree_selection | fail | Failed to apply to next/pending-fixes, riscv/for-next or riscv/master |
On 7/7/23 09:00, Palmer Dabbelt wrote: > RISC-V has an extended form of mapping symbols that we use to encode > the ISA when it changes in the middle of an ELF. This trips up modpost > as a build failure, I haven't yet verified it yet but I believe the > kallsyms difference should result in stacks looking sane again. > > Reported-by: Randy Dunlap <rdunlap@infradead.org> > Closes: https://lore.kernel.org/all/9d9e2902-5489-4bf0-d9cb-556c8e5d71c2@infradead.org/ > Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Thanks. > --- > Changes since v1 <20230707054007.32591-1-palmer@rivosinc.com/>: > > * Drop the unnecessary IS_RISCV define and just inline it. > --- > include/linux/module_symbol.h | 12 +++++++++++- > kernel/module/kallsyms.c | 2 +- > scripts/mod/modpost.c | 2 +- > 3 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h > index 7ace7ba30203..5b799942b243 100644 > --- a/include/linux/module_symbol.h > +++ b/include/linux/module_symbol.h > @@ -3,12 +3,22 @@ > #define _LINUX_MODULE_SYMBOL_H > > /* This ignores the intensely annoying "mapping symbols" found in ELF files. */ > -static inline int is_mapping_symbol(const char *str) > +static inline int is_mapping_symbol(const char *str, int is_riscv) > { > if (str[0] == '.' && str[1] == 'L') > return true; > if (str[0] == 'L' && str[1] == '0') > return true; > + /* > + * RISC-V defines various special symbols that start with "$". The > + * mapping symbols, which exist to differentiate between incompatible > + * instruction encodings when disassembling, show up all over the place > + * and are generally not meant to be treated like other symbols. So > + * just ignore any of the special symbols. > + */ > + if (is_riscv) > + return str[0] == '$'; > + > return str[0] == '$' && > (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') > && (str[2] == '\0' || str[2] == '.'); > diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c > index ef73ae7c8909..78a1ffc399d9 100644 > --- a/kernel/module/kallsyms.c > +++ b/kernel/module/kallsyms.c > @@ -289,7 +289,7 @@ static const char *find_kallsyms_symbol(struct module *mod, > * and inserted at a whim. > */ > if (*kallsyms_symbol_name(kallsyms, i) == '\0' || > - is_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) > + is_mapping_symbol(kallsyms_symbol_name(kallsyms, i), IS_ENABLED(CONFIG_RISCV))) > continue; > > if (thisval <= addr && thisval > bestval) { > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index b29b29707f10..7c71429d6502 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -1052,7 +1052,7 @@ static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) > > if (!name || !strlen(name)) > return 0; > - return !is_mapping_symbol(name); > + return !is_mapping_symbol(name, elf->hdr->e_machine == EM_RISCV); > } > > /* Look up the nearest symbol based on the section and the address */
On Fri, Jul 07, 2023 at 09:00:51AM -0700, Palmer Dabbelt wrote: > RISC-V has an extended form of mapping symbols that we use to encode > the ISA when it changes in the middle of an ELF. This trips up modpost > as a build failure, I haven't yet verified it yet but I believe the > kallsyms difference should result in stacks looking sane again. > > Reported-by: Randy Dunlap <rdunlap@infradead.org> > Closes: https://lore.kernel.org/all/9d9e2902-5489-4bf0-d9cb-556c8e5d71c2@infradead.org/ > Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Thanks, applied and pushed! Luis
Hello! On 07/07/2023 17:00, Palmer Dabbelt wrote: > RISC-V has an extended form of mapping symbols that we use to encode > the ISA when it changes in the middle of an ELF. This trips up modpost > as a build failure, I haven't yet verified it yet but I believe the > kallsyms difference should result in stacks looking sane again. > > Reported-by: Randy Dunlap <rdunlap@infradead.org> > Closes: https://lore.kernel.org/all/9d9e2902-5489-4bf0-d9cb-556c8e5d71c2@infradead.org/ > Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> > --- > Changes since v1 <20230707054007.32591-1-palmer@rivosinc.com/>: > > * Drop the unnecessary IS_RISCV define and just inline it. > --- > include/linux/module_symbol.h | 12 +++++++++++- > kernel/module/kallsyms.c | 2 +- > scripts/mod/modpost.c | 2 +- > 3 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h > index 7ace7ba30203..5b799942b243 100644 > --- a/include/linux/module_symbol.h > +++ b/include/linux/module_symbol.h > @@ -3,12 +3,22 @@ > #define _LINUX_MODULE_SYMBOL_H > > /* This ignores the intensely annoying "mapping symbols" found in ELF files. */ > -static inline int is_mapping_symbol(const char *str) > +static inline int is_mapping_symbol(const char *str, int is_riscv) > { > if (str[0] == '.' && str[1] == 'L') > return true; > if (str[0] == 'L' && str[1] == '0') > return true; > + /* > + * RISC-V defines various special symbols that start with "$". The > + * mapping symbols, which exist to differentiate between incompatible > + * instruction encodings when disassembling, show up all over the place > + * and are generally not meant to be treated like other symbols. So > + * just ignore any of the special symbols. > + */ > + if (is_riscv) > + return str[0] == '$'; > + > return str[0] == '$' && > (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') > && (str[2] == '\0' || str[2] == '.'); > diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c > index ef73ae7c8909..78a1ffc399d9 100644 > --- a/kernel/module/kallsyms.c > +++ b/kernel/module/kallsyms.c > @@ -289,7 +289,7 @@ static const char *find_kallsyms_symbol(struct module *mod, > * and inserted at a whim. > */ > if (*kallsyms_symbol_name(kallsyms, i) == '\0' || > - is_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) > + is_mapping_symbol(kallsyms_symbol_name(kallsyms, i), IS_ENABLED(CONFIG_RISCV))) > continue; > > if (thisval <= addr && thisval > bestval) { > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index b29b29707f10..7c71429d6502 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -1052,7 +1052,7 @@ static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) > > if (!name || !strlen(name)) > return 0; > - return !is_mapping_symbol(name); > + return !is_mapping_symbol(name, elf->hdr->e_machine == EM_RISCV); > } > > /* Look up the nearest symbol based on the section and the address */ Since this commit was added, our builders are failing with the following error ... kernel/scripts/mod/modpost.c: In function ‘is_valid_name’: kernel/scripts/mod/modpost.c:1055:57: error: ‘EM_RISCV’ undeclared (first use in this function) return !is_mapping_symbol(name, elf->hdr->e_machine == EM_RISCV); ^ We have had some cases of this before [0] and was fixed by ensuring this is defined if it is not. Thanks Jon [0] https://patchwork.kernel.org/project/linux-mm/patch/20210924224338.8vuOlQPWr%25akpm@linux-foundation.org/
diff --git a/include/linux/module_symbol.h b/include/linux/module_symbol.h index 7ace7ba30203..5b799942b243 100644 --- a/include/linux/module_symbol.h +++ b/include/linux/module_symbol.h @@ -3,12 +3,22 @@ #define _LINUX_MODULE_SYMBOL_H /* This ignores the intensely annoying "mapping symbols" found in ELF files. */ -static inline int is_mapping_symbol(const char *str) +static inline int is_mapping_symbol(const char *str, int is_riscv) { if (str[0] == '.' && str[1] == 'L') return true; if (str[0] == 'L' && str[1] == '0') return true; + /* + * RISC-V defines various special symbols that start with "$". The + * mapping symbols, which exist to differentiate between incompatible + * instruction encodings when disassembling, show up all over the place + * and are generally not meant to be treated like other symbols. So + * just ignore any of the special symbols. + */ + if (is_riscv) + return str[0] == '$'; + return str[0] == '$' && (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x') && (str[2] == '\0' || str[2] == '.'); diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index ef73ae7c8909..78a1ffc399d9 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -289,7 +289,7 @@ static const char *find_kallsyms_symbol(struct module *mod, * and inserted at a whim. */ if (*kallsyms_symbol_name(kallsyms, i) == '\0' || - is_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) + is_mapping_symbol(kallsyms_symbol_name(kallsyms, i), IS_ENABLED(CONFIG_RISCV))) continue; if (thisval <= addr && thisval > bestval) { diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index b29b29707f10..7c71429d6502 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1052,7 +1052,7 @@ static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) if (!name || !strlen(name)) return 0; - return !is_mapping_symbol(name); + return !is_mapping_symbol(name, elf->hdr->e_machine == EM_RISCV); } /* Look up the nearest symbol based on the section and the address */
RISC-V has an extended form of mapping symbols that we use to encode the ISA when it changes in the middle of an ELF. This trips up modpost as a build failure, I haven't yet verified it yet but I believe the kallsyms difference should result in stacks looking sane again. Reported-by: Randy Dunlap <rdunlap@infradead.org> Closes: https://lore.kernel.org/all/9d9e2902-5489-4bf0-d9cb-556c8e5d71c2@infradead.org/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> --- Changes since v1 <20230707054007.32591-1-palmer@rivosinc.com/>: * Drop the unnecessary IS_RISCV define and just inline it. --- include/linux/module_symbol.h | 12 +++++++++++- kernel/module/kallsyms.c | 2 +- scripts/mod/modpost.c | 2 +- 3 files changed, 13 insertions(+), 3 deletions(-)