| Message ID | 1454095114-4128-2-git-send-email-viro@ZenIV.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Friday 29 January 2016 19:18:24 Al Viro wrote: > From: Al Viro <viro@zeniv.linux.org.uk> > > Add asm-usable variants of EXPORT_SYMBOL/EXPORT_SYMBOL_GPL. This > commit just adds the default implementation; most of the architectures > can simply add export.h to asm/Kbuild and start using <asm/export.h> > from assembler. The area where the things might diverge from default > is the alignment; normally it's 8 bytes on 64bit targets and 4 on > 32bit ones, both for unsigned long and for struct kernel_symbol. > > Unfortunately, amd64 and m68k are unusual - m68k aligns to 2 bytes > (for both) and amd64 aligns struct kernel_symbol to 16 bytes. For > those we'll need to have asm/export.h overriding the constants used > by generic version (KSYM_ALIGN and KCRC_ALIGN for kernel_symbol and > unsigned long resp.) and including asm-generic/export.h. > > And no, __alignof__ would not do the trick - on amd64 __alignof__ > of struct kernel_symbol is 8, not 16. > > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- > include/asm-generic/export.h | 61 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 61 insertions(+) > create mode 100644 include/asm-generic/export.h > For asm-generic: Acked-by: Arnd Bergmann <arnd@arndb.de> -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Al Viro <viro@ZenIV.linux.org.uk> wrote: > Add asm-usable variants of EXPORT_SYMBOL/EXPORT_SYMBOL_GPL. This > commit just adds the default implementation; most of the architectures > can simply add export.h to asm/Kbuild and start using <asm/export.h> > from assembler. The area where the things might diverge from default > is the alignment; normally it's 8 bytes on 64bit targets and 4 on > 32bit ones, both for unsigned long and for struct kernel_symbol. > > Unfortunately, amd64 and m68k are unusual - m68k aligns to 2 bytes > (for both) and amd64 aligns struct kernel_symbol to 16 bytes. For > those we'll need to have asm/export.h overriding the constants used > by generic version (KSYM_ALIGN and KCRC_ALIGN for kernel_symbol and > unsigned long resp.) and including asm-generic/export.h. > > And no, __alignof__ would not do the trick - on amd64 __alignof__ > of struct kernel_symbol is 8, not 16. > > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: David Howells <dhowells@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h new file mode 100644 index 0000000..a1d44be --- /dev/null +++ b/include/asm-generic/export.h @@ -0,0 +1,61 @@ +#ifndef __ASM_GENERIC_EXPORT_H +#define __ASM_GENERIC_EXPORT_H + +#ifdef CONFIG_64BIT +#define __put .quad +#ifndef KSYM_ALIGN +#define KSYM_ALIGN 8 +#endif +#ifndef KCRC_ALIGN +#define KCRC_ALIGN 8 +#endif +#else +#define __put .long +#ifndef KSYM_ALIGN +#define KSYM_ALIGN 4 +#endif +#ifndef KCRC_ALIGN +#define KCRC_ALIGN 4 +#endif +#endif +/* + * note on .section use: @progbits vs %progbits nastiness doesn't matter, + * since we immediately emit into those sections anyway. + */ +.macro __EXPORT_SYMBOL name,sec +#ifdef CONFIG_MODULES + .globl __ksymtab_\name + .section ___ksymtab\sec+\name,"a" + .balign KSYM_ALIGN +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX + ___ksymtab_\name: __put _\name, ___kstrtab_\name +#else + __ksymtab_\name: __put \name, __kstrtab_\name +#endif + .previous + .section __ksymtab_strings,"a" +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX + ___kstrtab_\name: .asciz "_\name" +#else + __kstrtab_\name: .asciz "\name" +#endif + .previous +#ifdef CONFIG_MODVERSIONS + .section ___kcrctab\sec+\name,"a" + .balign KCRC_ALIGN +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX + ___kcrctab_\name: __put ___crc_\name + .weak ___crc_\name +#else + __kcrctab_\name: __put __crc_\name + .weak __crc_\name +#endif + .previous +#endif +#endif +.endm +#undef __put +#define EXPORT_SYMBOL(name) __EXPORT_SYMBOL name +#define EXPORT_SYMBOL_GPL(name) __EXPORT_SYMBOL name, _gpl + +#endif