Commit a7ec177e authored by Andreas Larsson's avatar Andreas Larsson
Browse files

sparc32: Fix truncated relocation errors when linking large kernels 



Use jumps instead of branches when jumping from one section to another
to avoid branches to addresses further away than 22 bit offsets can
handle that results in errors such as

arch/sparc/kernel/signal_32.o:(.fixup+0x0): relocation truncated to fit: R_SPARC_WDISP22 against `.text'

This is the same approach that was taken for sparc64 in commit
52eb053b ("[SPARC64]: Fix linkage of enormous kernels.")

Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202405080936.tWaJdO3P-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406240441.5zaoshVX-lkp@intel.com/
Link: https://lore.kernel.org/r/20240710092341.457591-1-andreas@gaisler.com


Signed-off-by: default avatarAndreas Larsson <andreas@gaisler.com>
parent e51f125b

arch/sparc/include/asm/uaccess_32.h

+4 −2
Original line number Diff line number Diff line
@@ -95,7 +95,8 @@ __asm__ __volatile__( \ 
		".section .fixup,#alloc,#execinstr\n\t"			\

		".align	4\n"						\

	"3:\n\t"							\

		"b	2b\n\t"						\

		"sethi	%%hi(2b), %0\n\t"				\

		"jmpl	%0 + %%lo(2b), %%g0\n\t"			\

		" mov	%3, %0\n\t"					\

		".previous\n\n\t"					\

		".section __ex_table,#alloc\n\t"			\
@@ -163,8 +164,9 @@ __asm__ __volatile__( \ 
		".section .fixup,#alloc,#execinstr\n\t"			\

		".align	4\n"						\

	"3:\n\t"							\

		"sethi	%%hi(2b), %0\n\t"				\

		"clr	%1\n\t"						\

		"b	2b\n\t"						\

		"jmpl	%0 + %%lo(2b), %%g0\n\t"			\

		" mov	%3, %0\n\n\t"					\

		".previous\n\t"						\

		".section __ex_table,#alloc\n\t"			\

arch/sparc/kernel/head_32.S

+11 −4
Original line number Diff line number Diff line
@@ -118,9 +118,12 @@ current_pc: 
		mov	%o7, %g3



		tst	%o0

		be	no_sun4u_here

		bne	2f

		 mov	%g4, %o7		/* Previous %o7. */



		sethi	%hi(no_sun4u_here), %l1

		jmpl	%l1 + %lo(no_sun4u_here), %g0

		 nop

2:

		mov	%o0, %l0		! stash away romvec

		mov	%o0, %g7		! put it here too

		mov	%o1, %l1		! stash away debug_vec too
@@ -195,7 +198,8 @@ halt_notsup: 
		sub	%o0, %l6, %o0

		call	%o1

		 nop

		ba	halt_me

		sethi	%hi(halt_me), %o0

		jmpl	%o0 + %lo(halt_me), %g0

		 nop



not_a_sun4:
@@ -431,8 +435,11 @@ leon_init: 
#ifdef CONFIG_SMP

		ldub	[%g2 + %lo(boot_cpu_id)], %g1

		cmp	%g1, 0xff		! unset means first CPU

		bne	leon_smp_cpu_startup	! continue only with master

		be 1f

		 sethi	%hi(leon_smp_cpu_startup), %g1

		jmpl	%g1 + %lo(leon_smp_cpu_startup), %g0

		 nop

1:

#endif

		/* Get CPU-ID from most significant 4-bit of ASR17 */

		rd     %asr17, %g1