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[PATCH] gas: xtensa: make trampolines relaxation work with jumps in slots other than 0
- From: Max Filippov <jcmvbkbc at gmail dot com>
- To: binutils at sourceware dot org
- Cc: Sterling Augustine <augustine dot sterling at gmail dot com>, David Weatherford <weath at cadence dot com>, Marc Gauthier <marc at cadence dot com>, linux-xtensa at linux-xtensa dot org, Max Filippov <jcmvbkbc at gmail dot com>
- Date: Wed, 22 Mar 2017 10:27:23 -0700
- Subject: [PATCH] gas: xtensa: make trampolines relaxation work with jumps in slots other than 0
- Authentication-results: sourceware.org; auth=none
add_jump_to_trampoline assumes that jump instruction is in slot 0,
when it's in other slot that results in fixup that references NULL symbol,
which results in segfault later in xtensa_make_cached_fixup.
Search for the non-NULL symbol in the tc_frag_data.slot_symbols and check
that there's exactly one such slot.
xtensa_relax_frag for RELAX_TRAMPOLINE reassigns fixup from the original
instruction with jump to generated jump in the trampoline frag, but does not
fix its fx_r_type or fx_size. That results in "undecodable fix" or
"fixup not contained within frag" error messages during relaxation.
Fix both these fields.
gas/
2017-03-22 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (xtensa_relax_frag): Change fx_size of the
reassigned fixup to size of jump instruction (3) and fx_r_type
to BFD_RELOC_XTENSA_SLOT0_OP, as there's only one slot.
(add_jump_to_trampoline): Search
origfrag->tc_frag_data.slot_symbols for the slot with non-NULL
symbol and use that slot instead of slot 0.
---
gas/config/tc-xtensa.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 356c319..c45c70d 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -9414,7 +9414,9 @@ xtensa_relax_frag (fragS *fragP, long stretch, int *stretched_p)
/* Move the fix-up from the original j insn to this one. */
fixP->fx_frag = fragP;
fixP->fx_where = fragP->fr_fix - 3;
+ fixP->fx_size = 3;
fixP->tc_fix_data.slot = 0;
+ fixP->fx_r_type = BFD_RELOC_XTENSA_SLOT0_OP;
xtensa_add_cached_fixup (&fixup_cache, fixP);
@@ -10045,11 +10047,21 @@ add_jump_to_trampoline (struct trampoline_frag *trampP, fragS *origfrag)
xtensa_format fmt;
xtensa_isa isa = xtensa_default_isa;
int growth = 0;
+ int i, slot = -1;
+
+ for (i = 0; i < MAX_SLOTS; ++i)
+ if (origfrag->tc_frag_data.slot_symbols[i])
+ {
+ gas_assert (slot == -1);
+ slot = i;
+ }
+
+ gas_assert (slot >= 0 && slot < MAX_SLOTS);
lsym = tramp->fr_symbol;
/* Assemble a jump to the target label in the trampoline frag. */
- tsym = origfrag->tc_frag_data.slot_symbols[0];
- toffset = origfrag-> tc_frag_data.slot_offsets[0];
+ tsym = origfrag->tc_frag_data.slot_symbols[slot];
+ toffset = origfrag-> tc_frag_data.slot_offsets[slot];
tinsn_init (&insn);
insn.insn_type = ITYPE_INSN;
insn.opcode = xtensa_j_opcode;
@@ -10069,8 +10081,8 @@ add_jump_to_trampoline (struct trampoline_frag *trampP, fragS *origfrag)
if (fixP)
fixP->fx_offset += 3;
/* Modify the original j to point here. */
- origfrag->tc_frag_data.slot_symbols[0] = lsym;
- origfrag->tc_frag_data.slot_offsets[0] = tramp->fr_fix - 3;
+ origfrag->tc_frag_data.slot_symbols[slot] = lsym;
+ origfrag->tc_frag_data.slot_offsets[slot] = tramp->fr_fix - 3;
/* If trampoline is full, remove it from the list. */
check_and_update_trampolines ();
--
2.1.4