Re: [PATCHv8 bpf-next 3/9] uprobe: Add uretprobe syscall to speed up return probe
From: Nathan Chancellor <nathan@kernel.org>
Date: 2024-06-14 20:07:32
Also in:
bpf, linux-api, linux-trace-kernel, lkml, loongarch
On Fri, Jun 14, 2024 at 09:26:59PM +0200, Jiri Olsa wrote:
On Fri, Jun 14, 2024 at 10:48:22AM -0700, Nathan Chancellor wrote:quoted
Hi Jiri, On Tue, Jun 11, 2024 at 01:21:52PM +0200, Jiri Olsa wrote:quoted
Adding uretprobe syscall instead of trap to speed up return probe....quoted
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2c83ba776fc7..2816e65729ac 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c@@ -1474,11 +1474,20 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) return ret; } +void * __weak arch_uprobe_trampoline(unsigned long *psize) +{ + static uprobe_opcode_t insn = UPROBE_SWBP_INSN;This change as commit ff474a78cef5 ("uprobe: Add uretprobe syscall to speed up return probe") in -next causes the following build error for ARCH=loongarch allmodconfig: In file included from include/linux/uprobes.h:49, from include/linux/mm_types.h:16, from include/linux/mmzone.h:22, from include/linux/gfp.h:7, from include/linux/xarray.h:16, from include/linux/list_lru.h:14, from include/linux/fs.h:13, from include/linux/highmem.h:5, from kernel/events/uprobes.c:13: kernel/events/uprobes.c: In function 'arch_uprobe_trampoline': arch/loongarch/include/asm/uprobes.h:12:33: error: initializer element is not constant 12 | #define UPROBE_SWBP_INSN larch_insn_gen_break(BRK_UPROBE_BP) | ^~~~~~~~~~~~~~~~~~~~ kernel/events/uprobes.c:1479:39: note: in expansion of macro 'UPROBE_SWBP_INSN' 1479 | static uprobe_opcode_t insn = UPROBE_SWBP_INSN;reproduced, could you please try the change below
Yeah, that fixes the issue for me. Tested-by: Nathan Chancellor <nathan@kernel.org> # build
quoted hunk ↗ jump to hunk
---diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2816e65729ac..6986bd993702 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c@@ -1476,8 +1476,9 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) void * __weak arch_uprobe_trampoline(unsigned long *psize) { - static uprobe_opcode_t insn = UPROBE_SWBP_INSN; + static uprobe_opcode_t insn; + insn = insn ?: UPROBE_SWBP_INSN; *psize = UPROBE_SWBP_INSN_SIZE; return &insn; }