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
52eb053b7191 ("[SPARC64]: Fix linkage of enormous kernels.")

Reported-by: kernel 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: Andreas Larsson <andreas@gaisler.com>

diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 9fd6c53644b61ec72815aee66722156b9a98777d..43284b6ec46a684360acaeb5eda65f39c4efed32 100644 (file)
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -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"                        \

diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S
index 964c61b5cd03665f27190a7afc0374211336c6d3..38345460d5420a295e941d53015d72a8c8d50be1 100644 (file)
--- a/arch/sparc/kernel/head_32.S
+++ b/arch/sparc/kernel/head_32.S
@@ -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