Commit 998b17d4 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Huacai Chen
Browse files

LoongArch: Make the users of larch_insn_gen_break() constant 



LoongArch defines UPROBE_SWBP_INSN as a function call and this breaks
arch_uprobe_trampoline() which uses it to initialize a static variable.

Add the new "__builtin_constant_p" helper, __emit_break(), and redefine
the current users of larch_insn_gen_break() to use it.

Fixes: ff474a78 ("uprobe: Add uretprobe syscall to speed up return probe")
Reported-by: default avatarNathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20240614174822.GA1185149@thelio-3990X/


Suggested-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Tested-by: default avatarTiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 3892b11e

arch/loongarch/include/asm/inst.h

+3 −0
Original line number Diff line number Diff line
@@ -532,6 +532,9 @@ static inline void emit_##NAME(union loongarch_instruction *insn, \ 


DEF_EMIT_REG0I15_FORMAT(break, break_op)



/* like emit_break(imm) but returns a constant expression */

#define __emit_break(imm)	((u32)((imm) | (break_op << 15)))



#define DEF_EMIT_REG0I26_FORMAT(NAME, OP)				\

static inline void emit_##NAME(union loongarch_instruction *insn,	\

			       int offset)				\

arch/loongarch/include/asm/uprobes.h

+2 −2
Original line number Diff line number Diff line
@@ -9,10 +9,10 @@ typedef u32 uprobe_opcode_t; 
#define MAX_UINSN_BYTES		8

#define UPROBE_XOL_SLOT_BYTES	MAX_UINSN_BYTES



#define UPROBE_SWBP_INSN	larch_insn_gen_break(BRK_UPROBE_BP)

#define UPROBE_SWBP_INSN	__emit_break(BRK_UPROBE_BP)

#define UPROBE_SWBP_INSN_SIZE	LOONGARCH_INSN_SIZE



#define UPROBE_XOLBP_INSN	larch_insn_gen_break(BRK_UPROBE_XOLBP)

#define UPROBE_XOLBP_INSN	__emit_break(BRK_UPROBE_XOLBP)



struct arch_uprobe {

	unsigned long	resume_era;

arch/loongarch/kernel/kprobes.c

+2 −2
Original line number Diff line number Diff line
@@ -4,8 +4,8 @@ 
#include <linux/preempt.h>

#include <asm/break.h>



#define KPROBE_BP_INSN		larch_insn_gen_break(BRK_KPROBE_BP)

#define KPROBE_SSTEPBP_INSN	larch_insn_gen_break(BRK_KPROBE_SSTEPBP)

#define KPROBE_BP_INSN		__emit_break(BRK_KPROBE_BP)

#define KPROBE_SSTEPBP_INSN	__emit_break(BRK_KPROBE_SSTEPBP)



DEFINE_PER_CPU(struct kprobe *, current_kprobe);

DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);