From 9ad39107ca6e4efcda0f48a6abf528844a2f11aa Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 4 Oct 2016 10:41:26 +1030 Subject: [PATCH] Fold arithmetic integer expressions Commit b751e639 regressed arm linux kernel builds, that have an ASSERT (((__hyp_idmap_text_end - (__hyp_idmap_text_start & ~ (((0x1 << 0xc) - 0x1)))) <= (0x1 << 0xc)), HYP init code too big or misaligned) Due to some insanity in ld expression evaluation, the integer values 0x1 and 0xc above are treated as absolute addresses (ie. they have an associated section, *ABS*, see exp_fold_tree_1 case etree_value) while the expression (0x1 << 0xc) has a plain number result. The left hand side of the inequality happens to evaluate to a "negative" .text section relative value. Comparing a section relative value against an absolute value works since the section relative value is first converted to absolute. Comparing a section relative value against a number just compares the offsets, which fails since the "negative" offset is really a very large positive number. This patch works around the problem by folding integer expressions, so the assert again becomes ASSERT (((__hyp_idmap_text_end - (__hyp_idmap_text_start & 0xfffffffffffff000)) <= 0x1000), HYP init code too big or misaligned) * ldexp.c (exp_value_fold): New function. (exp_unop, exp_binop, exp_trinop): Use it. --- ld/ChangeLog | 5 +++++ ld/ldexp.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/ld/ChangeLog b/ld/ChangeLog index 3ad2a7affa..8b22c50a1f 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,8 @@ +2016-10-04 Alan Modra + + * ldexp.c (exp_value_fold): New function. + (exp_unop, exp_binop, exp_trinop): Use it. + 2016-09-30 Alan Modra * scripttempl/v850.sc: Don't reference __ctbp, __ep, __gp when diff --git a/ld/ldexp.c b/ld/ldexp.c index a560643fb3..9f88144b67 100644 --- a/ld/ldexp.c +++ b/ld/ldexp.c @@ -1252,6 +1252,19 @@ exp_fold_tree_no_dot (etree_type *tree) exp_fold_tree_1 (tree); } +static void +exp_value_fold (etree_type *tree) +{ + exp_fold_tree_no_dot (tree); + if (expld.result.valid_p) + { + tree->type.node_code = INT; + tree->value.value = expld.result.value; + tree->value.str = NULL; + tree->type.node_class = etree_value; + } +} + etree_type * exp_binop (int code, etree_type *lhs, etree_type *rhs) { @@ -1263,6 +1276,12 @@ exp_binop (int code, etree_type *lhs, etree_type *rhs) new_e->binary.lhs = lhs; new_e->binary.rhs = rhs; new_e->type.node_class = etree_binary; + if (lhs->type.node_class == etree_value + && rhs->type.node_class == etree_value + && code != ALIGN_K + && code != DATA_SEGMENT_ALIGN + && code != DATA_SEGMENT_RELRO_END) + exp_value_fold (new_e); return new_e; } @@ -1278,6 +1297,10 @@ exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs) new_e->trinary.cond = cond; new_e->trinary.rhs = rhs; new_e->type.node_class = etree_trinary; + if (cond->type.node_class == etree_value + && lhs->type.node_class == etree_value + && rhs->type.node_class == etree_value) + exp_value_fold (new_e); return new_e; } @@ -1291,6 +1314,12 @@ exp_unop (int code, etree_type *child) new_e->unary.type.lineno = child->type.lineno; new_e->unary.child = child; new_e->unary.type.node_class = etree_unary; + if (child->type.node_class == etree_value + && code != ALIGN_K + && code != ABSOLUTE + && code != NEXT + && code != DATA_SEGMENT_END) + exp_value_fold (new_e); return new_e; } -- 2.34.1