Re: [PATCH] LoongArch: uprobes: make UPROBE_SWBP_INSN/UPROBE_XOLBP_INSN constant
From: Andrii Nakryiko <hidden>
Date: 2024-06-27 16:51:48
Also in:
bpf, lkml, loongarch
On Thu, Jun 27, 2024 at 9:04 AM Oleg Nesterov [off-list ref] wrote:
LoongArch defines UPROBE_SWBP_INSN as a function call and this breaks
arch_uprobe_trampoline() which uses it to initialize a static variable.
Fixes: ff474a78cef5 ("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/ (local)
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
arch/loongarch/include/asm/uprobes.h | 6 ++++--
arch/loongarch/kernel/uprobes.c | 8 ++++++++
2 files changed, 12 insertions(+), 2 deletions(-)LGTM. Acked-by: Andrii Nakryiko <andrii@kernel.org>
quoted hunk ↗ jump to hunk
diff --git a/arch/loongarch/include/asm/uprobes.h b/arch/loongarch/include/asm/uprobes.h index c8f59983f702..18221eb9a8b0 100644 --- a/arch/loongarch/include/asm/uprobes.h +++ b/arch/loongarch/include/asm/uprobes.h@@ -6,13 +6,15 @@ typedef u32 uprobe_opcode_t; +#define __emit_break(imm) (uprobe_opcode_t)((imm) | (break_op << 15)) + #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)
this looks correct (but based on pure code inspection)
quoted hunk ↗ jump to hunk
struct arch_uprobe { unsigned long resume_era;diff --git a/arch/loongarch/kernel/uprobes.c b/arch/loongarch/kernel/uprobes.c index 87abc7137b73..90462d94c28f 100644 --- a/arch/loongarch/kernel/uprobes.c +++ b/arch/loongarch/kernel/uprobes.c@@ -7,6 +7,14 @@ #define UPROBE_TRAP_NR UINT_MAX +static __init int check_emit_break(void) +{ + BUG_ON(UPROBE_SWBP_INSN != larch_insn_gen_break(BRK_UPROBE_BP)); + BUG_ON(UPROBE_XOLBP_INSN != larch_insn_gen_break(BRK_UPROBE_XOLBP)); + return 0; +} +arch_initcall(check_emit_break); +
I wouldn't even bother with this, but whatever.
int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
struct mm_struct *mm, unsigned long addr)
{
--
2.25.1.362.g51ebf55