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FRV: arrange things such that BRA can reach from the trap table
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Arrange the sections in the FRV arch so that a BRA instruction with a
16-bit displacement can always reach from the trap table to entry.S,
tlb-miss.S and break.S.

The problem otherwise is that the linker can insert sufficient code between
the slots in the trap table and the targets of the branch instructions in
those slots that the displacement field in the instruction isn't
sufficiently large.  This is because the branch targets were in the .text
section along with most of the other code in the kernel.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Howells authored and Linus Torvalds committed Nov 29, 2007
1 parent 9e6c1e6 commit 3c83567
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Showing 4 changed files with 18 additions and 15 deletions.
2 changes: 1 addition & 1 deletion arch/frv/kernel/break.S
Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@ __break_trace_through_exceptions:
# entry point for Break Exceptions/Interrupts
#
###############################################################################
.text
.section .text.break
.balign 4
.globl __entry_break
__entry_break:
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2 changes: 1 addition & 1 deletion arch/frv/kernel/entry.S
Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,7 @@

#define nr_syscalls ((syscall_table_size)/4)

.text
.section .text.entry
.balign 4

.macro LEDS val
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27 changes: 15 additions & 12 deletions arch/frv/kernel/vmlinux.lds.S
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,12 @@ SECTIONS
*(.data.init_task)
}

. = ALIGN(4096);
.data.page_aligned : { *(.data.idt) }

. = ALIGN(L1_CACHE_BYTES);
.data.cacheline_aligned : { *(.data.cacheline_aligned) }

.trap : {
/* trap table management - read entry-table.S before modifying */
. = ALIGN(8192);
Expand All @@ -86,28 +92,25 @@ SECTIONS
*(.trap.break)
}

. = ALIGN(4096);
.data.page_aligned : { *(.data.idt) }

. = ALIGN(L1_CACHE_BYTES);
.data.cacheline_aligned : { *(.data.cacheline_aligned) }

/* Text and read-only data */
. = ALIGN(4);
_text = .;
_stext = .;
.text : {
*(
.text.start .text.*
*(.text.start)
*(.text.entry)
*(.text.break)
*(.text.tlbmiss)
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
#ifdef CONFIG_DEBUG_INFO
*(
.init.text
.exit.text
.exitcall.exit
#endif
)
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
#endif
*(.fixup)
*(.gnu.warning)
*(.exitcall.exit)
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2 changes: 1 addition & 1 deletion arch/frv/mm/tlb-miss.S
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@
#include <asm/highmem.h>
#include <asm/spr-regs.h>

.section .text
.section .text.tlbmiss
.balign 4

.globl __entry_insn_mmu_miss
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