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LoongArch: uprobes: Remove user_{en,dis}able_single_step()

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commit 0b326b2371f94e798137cc1a3c5c2eef2bc69061 upstream.

When executing the "perf probe" and "perf stat" test cases about some
cryptographic algorithm, the output shows that "Trace/breakpoint trap".
This is because it uses the software singlestep breakpoint for uprobes
on LoongArch, and no need to use the hardware singlestep. So just remove
the related function call to user_{en,dis}able_single_step() for uprobes
on LoongArch.

How to reproduce:

Please make sure CONFIG_UPROBE_EVENTS is set and openssl supports sm2
algorithm, then execute the following command.

cd tools/perf && make
./perf probe -x /usr/lib64/libcrypto.so BN_mod_mul_montgomery
./perf stat -e probe_libcrypto:BN_mod_mul_montgomery openssl speed sm2

Cc: stable@vger.kernel.org
Fixes: 19bc6cb640 ("LoongArch: Add uprobes support")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tiezhu Yang
2025-05-14 22:18:10 +08:00
committed by Greg Kroah-Hartman
parent c92b99c4c0
commit 88650dde2e
1 changed files with 0 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/loongarch/kernel/uprobes.c
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@@ -42,7 +42,6 @@ int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
utask->autask.saved_trap_nr = current->thread.trap_nr;
current->thread.trap_nr = UPROBE_TRAP_NR;
instruction_pointer_set(regs, utask->xol_vaddr);
user_enable_single_step(current);
return 0;
}
@@ -59,8 +58,6 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
else
instruction_pointer_set(regs, utask->vaddr + LOONGARCH_INSN_SIZE);
user_disable_single_step(current);
return 0;
}
@@ -70,7 +67,6 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
current->thread.trap_nr = utask->autask.saved_trap_nr;
instruction_pointer_set(regs, utask->vaddr);
user_disable_single_step(current);
}
bool arch_uprobe_xol_was_trapped(struct task_struct *t)