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LoongArch: Make the users of larch_insn_gen_break() constant

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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: ff474a78ce ("uprobe: Add uretprobe syscall to speed up return probe")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20240614174822.GA1185149@thelio-3990X/
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Oleg Nesterov 2024-07-20 22:41:07 +08:00 committed by Huacai Chen
parent 3892b11eac
commit 998b17d444
3 changed files with 7 additions and 4 deletions
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3
arch/loongarch/include/asm/inst.h
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@ -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) \

4
arch/loongarch/include/asm/uprobes.h
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@ -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;

4
arch/loongarch/kernel/kprobes.c
View File

@ -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);