Commit 3e7b19ef authored Nov 07, 2009 by Alan Jenkins Committed by Rusty Russell Dec 15, 2009

ARM: unexport symbols used to implement floating point emulation

The Kconfigs for in-tree floating point emulation do not allow building
as modules. That leaves the Acorn FPEmulator module. I found two public
releases of this as a binary module for 2.1 and 2.2 kernels, optimized
for ARMV4.[1] If there is a resurgence of interest in this, the symbols
can always be re-exported.

This allows the EXPORT_SYMBOL_ALIAS() hack to be removed. The ulterior
motive here is that EXPORT_SYMBOL_ALIAS() makes it harder to sort the
resulting kernel symbol tables.  Sorted symbol tables will allow faster
symbol resolution during module loading.

Note that fp_send_sigs() and fp_printk() are simply aliases for existing
exports and add no obvious value.  Similarly fp_enter could easily be
renamed to kern_fp_enter at the point of definition. Therefore removing
EXPORT_SYMBOL_ALIAS will not serve as a material obstacle to re-adding
the exports should they be desired in future.

Build tested only.

[1] http://ftp.arm.linux.org.uk/pub/linux/arm/fpemulator/



Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

parent e3f28c13

arch/arm/kernel/armksyms.c

+0 −20

Original line number	Diff line number	Diff line
		@@ -48,27 +48,7 @@ extern void __aeabi_uidivmod(void);
		extern void __aeabi_ulcmp(void);

		extern void fpundefinstr(void);
		extern void fp_enter(void);

		/*
		* This has a special calling convention; it doesn't
		* modify any of the usual registers, except for LR.
		*/
		#define EXPORT_CRC_ALIAS(sym) __CRC_SYMBOL(sym, "")

		#define EXPORT_SYMBOL_ALIAS(sym,orig) \
		EXPORT_CRC_ALIAS(sym) \
		static const struct kernel_symbol __ksymtab_##sym \
		__used __attribute__((section("__ksymtab"))) = \
		{ (unsigned long)&orig, #sym };

		/*
		* floating point math emulator support.
		* These symbols will never change their calling convention...
		*/
		EXPORT_SYMBOL_ALIAS(kern_fp_enter,fp_enter);
		EXPORT_SYMBOL_ALIAS(fp_printk,printk);
		EXPORT_SYMBOL_ALIAS(fp_send_sig,send_sig);

		EXPORT_SYMBOL(__backtrace);