module: Make is_mapping_symbol() return bool

The return value of is_mapping_symbol() is true or false,
so change its type to reflect that.

Suggested-by: Xi Zhang <zhangxi@kylinos.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

modpost, kallsyms: Treat add '$'-prefixed symbols as mapping symbols

Trying to restrict the '$'-prefix change to RISC-V caused some fallout,
so let's just treat all those symbols as special.

Fixes: c05780ef3c190 ("module: Ignore RISC-V mapping symbols too")
Link: https://lore.kernel.org/all/20230712015747.77263-1-wangkefeng.wang@huawei.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

module: Ignore RISC-V mapping symbols too

RISC-V has an extended form of mapping symbols that we use to encode
the ISA when it changes in the middle of an ELF. This trips up modpost
as a build failure, I haven't yet verified it yet but I believe the
kallsyms difference should result in stacks looking sane again.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/all/9d9e2902-5489-4bf0-d9cb-556c8e5d71c2@infradead.org/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

module: Ignore L0 and rename is_arm_mapping_symbol()

The L0 symbol is generated when build module on LoongArch, ignore it in
modpost and when looking at module symbols, otherwise we can not see the
expected call trace.

Now is_arm_mapping_symbol() is not only for ARM, in order to reflect the
reality, rename is_arm_mapping_symbol() to is_mapping_symbol().

This is related with commit c17a2538704f ("mksysmap: Fix the mismatch of
'L0' symbols in System.map").

(1) Simple test case

[loongson@linux hello]$ cat hello.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/printk.h>

static void test_func(void)
{
pr_info("This is a test\n");
dump_stack();
}

static int __init hello_init(void)
{
pr_warn("Hello, world\n");
test_func();

return 0;
}

static void __exit hello_exit(void)
{
pr_warn("Goodbye\n");
}

module_init(hello_init);
module_exit(hello_exit);
MODULE_LICENSE("GPL");
[loongson@linux hello]$ cat Makefile
obj-m:=hello.o

ccflags-y += -g -Og

all:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) clean

(2) Test environment

system: LoongArch CLFS 5.5
https://github.com/sunhaiyong1978/CLFS-for-LoongArch/releases/tag/5.0
It needs to update grub to avoid booting error "invalid magic number".

kernel: 6.3-rc1 with loongson3_defconfig + CONFIG_DYNAMIC_FTRACE=y

(3) Test result

Without this patch:

[root@linux hello]# insmod hello.ko
[root@linux hello]# dmesg
...
Hello, world
This is a test
...
Call Trace:
[<9000000000223728>] show_stack+0x68/0x18c
[<90000000013374cc>] dump_stack_lvl+0x60/0x88
[<ffff800002050028>] L0\x01+0x20/0x2c [hello]
[<ffff800002058028>] L0\x01+0x20/0x30 [hello]
[<900000000022097c>] do_one_initcall+0x88/0x288
[<90000000002df890>] do_init_module+0x54/0x200
[<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114
[<90000000013382e8>] do_syscall+0x7c/0x94
[<9000000000221e3c>] handle_syscall+0xbc/0x158

With this patch:

[root@linux hello]# insmod hello.ko
[root@linux hello]# dmesg
...
Hello, world
This is a test
...
Call Trace:
[<9000000000223728>] show_stack+0x68/0x18c
[<90000000013374cc>] dump_stack_lvl+0x60/0x88
[<ffff800002050028>] test_func+0x28/0x34 [hello]
[<ffff800002058028>] hello_init+0x28/0x38 [hello]
[<900000000022097c>] do_one_initcall+0x88/0x288
[<90000000002df890>] do_init_module+0x54/0x200
[<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114
[<90000000013382e8>] do_syscall+0x7c/0x94
[<9000000000221e3c>] handle_syscall+0xbc/0x158

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Youling Tang <tangyouling@loongson.cn> # for LoongArch
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

module: Move is_arm_mapping_symbol() to module_symbol.h

In order to avoid duplicated code, move is_arm_mapping_symbol() to
include/linux/module_symbol.h, then remove is_arm_mapping_symbol()
in the other places.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>