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| author | Evan Green <evan@rivosinc.com> | 2024-02-27 14:56:41 -0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-03-01 07:14:59 -0800 |
| commit | a29bb320a1a1daa8add4d213fc70f273810dd91a (patch) | |
| tree | e656191bcb10e88c4a067cf5ed3b277103f8f77d /include | |
| parent | 78308ce77ad55191d2e578bbcd19bb55c68926cb (diff) | |
| download | glibc-a29bb320a1a1daa8add4d213fc70f273810dd91a.tar.gz glibc-a29bb320a1a1daa8add4d213fc70f273810dd91a.tar.xz glibc-a29bb320a1a1daa8add4d213fc70f273810dd91a.zip | |
riscv: Enable multi-arg ifunc resolvers
RISC-V is apparently the first architecture to pass more than one argument to ifunc resolvers. The helper macros in libc-symbols.h, __ifunc_resolver(), __ifunc(), and __ifunc_hidden(), are incompatible with this. These macros have an "arg" (non-final) parameter that represents the parameter signature of the ifunc resolver. The result is an inability to pass the required comma through in a single preprocessor argument. Rearrange the __ifunc_resolver() macro to be variadic, and pass the types as those variable parameters. Move the guts of __ifunc() and __ifunc_hidden() into new macros, __ifunc_args(), and __ifunc_args_hidden(), that pass the variable arguments down through to __ifunc_resolver(). Then redefine __ifunc() and __ifunc_hidden(), which are used in a bunch of places, to simply shuffle the arguments down into __ifunc_args[_hidden]. Finally, define a riscv-ifunc.h header, which provides convenience macros to those looking to write ifunc selectors that use both arguments. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Florian Weimer <fweimer@redhat.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/libc-symbols.h | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/include/libc-symbols.h b/include/libc-symbols.h index e21bb599b3..4367aa6740 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -667,9 +667,9 @@ for linking") #endif /* Helper / base macros for indirect function symbols. */ -#define __ifunc_resolver(type_name, name, expr, arg, init, classifier) \ +#define __ifunc_resolver(type_name, name, expr, init, classifier, ...) \ classifier inhibit_stack_protector \ - __typeof (type_name) *name##_ifunc (arg) \ + __typeof (type_name) *name##_ifunc (__VA_ARGS__) \ { \ init (); \ __typeof (type_name) *res = expr; \ @@ -677,13 +677,13 @@ for linking") } #ifdef HAVE_GCC_IFUNC -# define __ifunc(type_name, name, expr, arg, init) \ +# define __ifunc_args(type_name, name, expr, init, ...) \ extern __typeof (type_name) name __attribute__ \ ((ifunc (#name "_ifunc"))); \ - __ifunc_resolver (type_name, name, expr, arg, init, static) + __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__) -# define __ifunc_hidden(type_name, name, expr, arg, init) \ - __ifunc (type_name, name, expr, arg, init) +# define __ifunc_args_hidden(type_name, name, expr, init, ...) \ + __ifunc_args (type_name, name, expr, init, __VA_ARGS__) #else /* Gcc does not support __attribute__ ((ifunc (...))). Use the old behaviour as fallback. But keep in mind that the debug information for the ifunc @@ -694,18 +694,24 @@ for linking") different signatures. (Gcc support is disabled at least on a ppc64le Ubuntu 14.04 system.) */ -# define __ifunc(type_name, name, expr, arg, init) \ +# define __ifunc_args(type_name, name, expr, init, ...) \ extern __typeof (type_name) name; \ - __typeof (type_name) *name##_ifunc (arg) __asm__ (#name); \ - __ifunc_resolver (type_name, name, expr, arg, init,) \ + __typeof (type_name) *name##_ifunc (__VA_ARGS__) __asm__ (#name); \ + __ifunc_resolver (type_name, name, expr, init, , __VA_ARGS__) \ __asm__ (".type " #name ", %gnu_indirect_function"); -# define __ifunc_hidden(type_name, name, expr, arg, init) \ +# define __ifunc_args_hidden(type_name, name, expr, init, ...) \ extern __typeof (type_name) __libc_##name; \ - __ifunc (type_name, __libc_##name, expr, arg, init) \ + __ifunc (type_name, __libc_##name, expr, __VA_ARGS__, init) \ strong_alias (__libc_##name, name); #endif /* !HAVE_GCC_IFUNC */ +#define __ifunc(type_name, name, expr, arg, init) \ + __ifunc_args (type_name, name, expr, init, arg) + +#define __ifunc_hidden(type_name, name, expr, arg, init) \ + __ifunc_args_hidden (type_name, name, expr, init, arg) + /* The following macros are used for indirect function symbols in libc.so. First of all, you need to have the function prototyped somewhere, say in foo.h: |