Commit 15d5daa0 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Luis Chamberlain
Browse files

kallsyms: remove unused arch_get_kallsym() helper 



The arch_get_kallsym() function was introduced so that x86 could override
it, but that override was removed in bf904d27 ("x86/pti/64: Remove
the SYSCALL64 entry trampoline"), so now this does nothing except causing
a warning about a missing prototype:

kernel/kallsyms.c:662:12: error: no previous prototype for 'arch_get_kallsym' [-Werror=missing-prototypes]
  662 | int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value,

Restore the old behavior before d83212d5 ("kallsyms, x86: Export
addresses of PTI entry trampolines") to simplify the code and avoid
the warning.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Tested-by: default avatarAlan Maguire <alan.maguire@oracle.com>
[mcgrof: fold in bpf selftest fix]
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent cb0b50b8

kernel/kallsyms.c

+1 −27
Original line number Diff line number Diff line
@@ -646,7 +646,6 @@ int sprint_backtrace_build_id(char *buffer, unsigned long address) 
/* To avoid using get_symbol_offset for every symbol, we carry prefix along. */

struct kallsym_iter {

	loff_t pos;

	loff_t pos_arch_end;

	loff_t pos_mod_end;

	loff_t pos_ftrace_mod_end;

	loff_t pos_bpf_end;
@@ -659,29 +658,9 @@ struct kallsym_iter { 
	int show_value;

};



int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value,

			    char *type, char *name)

{

	return -EINVAL;

}



static int get_ksymbol_arch(struct kallsym_iter *iter)

{

	int ret = arch_get_kallsym(iter->pos - kallsyms_num_syms,

				   &iter->value, &iter->type,

				   iter->name);



	if (ret < 0) {

		iter->pos_arch_end = iter->pos;

		return 0;

	}



	return 1;

}



static int get_ksymbol_mod(struct kallsym_iter *iter)

{

	int ret = module_get_kallsym(iter->pos - iter->pos_arch_end,

	int ret = module_get_kallsym(iter->pos - kallsyms_num_syms,

				     &iter->value, &iter->type,

				     iter->name, iter->module_name,

				     &iter->exported);
@@ -764,7 +743,6 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) 
	iter->nameoff = get_symbol_offset(new_pos);

	iter->pos = new_pos;

	if (new_pos == 0) {

		iter->pos_arch_end = 0;

		iter->pos_mod_end = 0;

		iter->pos_ftrace_mod_end = 0;

		iter->pos_bpf_end = 0;
@@ -780,10 +758,6 @@ static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) 
{

	iter->pos = pos;



	if ((!iter->pos_arch_end || iter->pos_arch_end > pos) &&

	    get_ksymbol_arch(iter))

		return 1;



	if ((!iter->pos_mod_end || iter->pos_mod_end > pos) &&

	    get_ksymbol_mod(iter))

		return 1;

tools/testing/selftests/bpf/progs/bpf_iter_ksym.c

+1 −3
Original line number Diff line number Diff line
@@ -59,9 +59,7 @@ int dump_ksym(struct bpf_iter__ksym *ctx) 
	} else {

		BPF_SEQ_PRINTF(seq, "0x%llx %c %s ", value, type, iter->name);

	}

	if (!iter->pos_arch_end || iter->pos_arch_end > iter->pos)

		BPF_SEQ_PRINTF(seq, "CORE ");

	else if (!iter->pos_mod_end || iter->pos_mod_end > iter->pos)

	if (!iter->pos_mod_end || iter->pos_mod_end > iter->pos)

		BPF_SEQ_PRINTF(seq, "MOD ");

	else if (!iter->pos_ftrace_mod_end || iter->pos_ftrace_mod_end > iter->pos)

		BPF_SEQ_PRINTF(seq, "FTRACE_MOD ");