Commit 54f698f3 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

Merge branch 'x86/debug' into core/urgent 

Pick up the two pending objtool patches as the next round of objtool fixes
depend on them.
parents cac9b9a4 e55a7325

include/linux/compiler.h

+5 −0
Original line number Diff line number Diff line
@@ -116,9 +116,14 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, 
	".pushsection .discard.unreachable\n\t"				\

	".long 999b - .\n\t"						\

	".popsection\n\t"



/* Annotate a C jump table to allow objtool to follow the code flow */

#define __annotate_jump_table __section(".rodata..c_jump_table")



#else

#define annotate_reachable()

#define annotate_unreachable()

#define __annotate_jump_table

#endif



#ifndef ASM_UNREACHABLE

kernel/bpf/core.c

+1 −2
Original line number Diff line number Diff line
@@ -1299,7 +1299,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) 
{

#define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y

#define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z

	static const void *jumptable[256] = {

	static const void * const jumptable[256] __annotate_jump_table = {

		[0 ... 255] = &&default_label,

		/* Now overwrite non-defaults ... */

		BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
@@ -1558,7 +1558,6 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) 
		BUG_ON(1);

		return 0;

}

STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */



#define PROG_NAME(stack_size) __bpf_prog_run##stack_size

#define DEFINE_BPF_PROG_RUN(stack_size) \

tools/objtool/check.c

+20 −7
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ 


#define FAKE_JUMP_OFFSET -1



#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"



struct alternative {

	struct list_head list;

	struct instruction *insn;
@@ -1035,9 +1037,15 @@ static struct rela *find_switch_table(struct objtool_file *file, 


		/*

		 * Make sure the .rodata address isn't associated with a

		 * symbol.  gcc jump tables are anonymous data.

		 * symbol.  GCC jump tables are anonymous data.

		 *

		 * Also support C jump tables which are in the same format as

		 * switch jump tables.  For objtool to recognize them, they

		 * need to be placed in the C_JUMP_TABLE_SECTION section.  They

		 * have symbols associated with them.

		 */

		if (find_symbol_containing(rodata_sec, table_offset))

		if (find_symbol_containing(rodata_sec, table_offset) &&

		    strcmp(rodata_sec->name, C_JUMP_TABLE_SECTION))

			continue;



		rodata_rela = find_rela_by_dest(rodata_sec, table_offset);
@@ -1277,13 +1285,18 @@ static void mark_rodata(struct objtool_file *file) 
	bool found = false;



	/*

	 * This searches for the .rodata section or multiple .rodata.func_name

	 * sections if -fdata-sections is being used. The .str.1.1 and .str.1.8

	 * rodata sections are ignored as they don't contain jump tables.

	 * Search for the following rodata sections, each of which can

	 * potentially contain jump tables:

	 *

	 * - .rodata: can contain GCC switch tables

	 * - .rodata.<func>: same, if -fdata-sections is being used

	 * - .rodata..c_jump_table: contains C annotated jump tables

	 *

	 * .rodata.str1.* sections are ignored; they don't contain jump tables.

	 */

	for_each_sec(file, sec) {

		if (!strncmp(sec->name, ".rodata", 7) &&

		    !strstr(sec->name, ".str1.")) {

		if ((!strncmp(sec->name, ".rodata", 7) && !strstr(sec->name, ".str1.")) ||

		    !strcmp(sec->name, C_JUMP_TABLE_SECTION)) {

			sec->rodata = true;

			found = true;

		}