Lines Matching +full:alternative +full:- +full:a

1 // SPDX-License-Identifier: GPL-2.0-or-later
15 	 * Recompute orig_len for nested ALTERNATIVE()s.  in arch_handle_alternative()
17 	if (group && group->orig_sec == alt->orig_sec &&  in arch_handle_alternative()
18 	             group->orig_off == alt->orig_off) {  in arch_handle_alternative()
22 			unsigned int len = max(iter->orig_len, alt->orig_len);  in arch_handle_alternative()
23 			iter->orig_len = alt->orig_len = len;  in arch_handle_alternative()
38 		 * If UACCESS validation is enabled; force that alternative;  in arch_handle_alternative()
42 		 * alternative code flow at the same time, in that case we can  in arch_handle_alternative()
47 			alt->skip_orig = true;  in arch_handle_alternative()
49 			alt->skip_alt = true;  in arch_handle_alternative()
54 		 * feature path which is a "very very small percentage of  in arch_handle_alternative()
57 		alt->skip_orig = true;  in arch_handle_alternative()
76  *    This is the most common case by far.  It jumps to an address in a simple
81  *    This is caused by a rare GCC quirk, currently only seen in three driver
82  *    functions in the kernel, only with certain obscure non-distro configs.
84  *    As part of an optimization, GCC makes a copy of an existing switch jump
85  *    table, modifies it, and then hard-codes the jump (albeit with an indirect
86  *    jump) to use a single entry in the table.  The rest of the jump table and
89  *    In such a case we can just crudely ignore all unreachable instruction
91  *    for the function, but that would require redesigning the code quite a
93  *    warnings are of questionable value anyway, and this is such a rare issue.
99  *    This is a fairly uncommon pattern which is new for GCC 6.  As of this
102  *    As of GCC 7 there are quite a few more of these and the 'in between' code
118 	/* look for a relocation which references .rodata */  in arch_find_switch_table()
119 	text_reloc = find_reloc_by_dest_range(file->elf, insn->sec,  in arch_find_switch_table()
120 					      insn->offset, insn->len);  in arch_find_switch_table()
121 	if (!text_reloc || text_reloc->sym->type != STT_SECTION ||  in arch_find_switch_table()
122 	    !text_reloc->sym->sec->rodata)  in arch_find_switch_table()
126 	table_sec = text_reloc->sym->sec;  in arch_find_switch_table()
132 	 * Make sure the .rodata address isn't associated with a  in arch_find_switch_table()
141 	    strcmp(table_sec->name, C_JUMP_TABLE_SECTION))  in arch_find_switch_table()
145 	 * Each table entry has a rela associated with it.  The rela  in arch_find_switch_table()
149 	rodata_reloc = find_reloc_by_dest(file->elf, table_sec, table_offset);  in arch_find_switch_table()
154 	 * Use of RIP-relative switch jumps is quite rare, and  in arch_find_switch_table()
155 	 * indicates a rare GCC quirk/bug which can leave dead  in arch_find_switch_table()
159 		file->ignore_unreachables = true;  in arch_find_switch_table()