From: He Zhe <zhe.he@xxxxxxxxxxxxx> commit d47422d953e258ad587b5edf2274eb95d08bdc7d upstream. As stated in linux/errno.h, ENOTSUPP should never be seen by user programs. When we set up uprobe with 32-bit perf and arm64 kernel, we would see the following vague error without useful hint. The sys_perf_event_open() syscall returned with 524 (INTERNAL ERROR: strerror_r(524, [buf], 128)=22) Use EOPNOTSUPP instead to indicate such cases. Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210223082535.48730-1-zhe.he@xxxxxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/kernel/probes/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/kernel/probes/uprobes.c +++ b/arch/arm64/kernel/probes/uprobes.c @@ -38,7 +38,7 @@ int arch_uprobe_analyze_insn(struct arch /* TODO: Currently we do not support AARCH32 instruction probing */ if (mm->context.flags & MMCF_AARCH32) - return -ENOTSUPP; + return -EOPNOTSUPP; else if (!IS_ALIGNED(addr, AARCH64_INSN_SIZE)) return -EINVAL;