[PATCH] RISC-V: Fix error code returned by riscv_hartid_to_cpuid()
palmer at dabbelt.com
Fri Apr 23 08:15:55 BST 2021
On Thu, 15 Apr 2021 01:55:22 PDT (-0700), Anup Patel wrote:
> We should return a negative error code upon failure in
Not just should: the PLIC driver assumed this was the return flavor and
will overflow a per_cpu because it doesn't detect the error. IIUC this
will manifest if we have more harts that NR_CPUS, which is a possible
That said, it's gone unnoticed for ~3 years so I'm inclined to leave it
out of fixes because I have nothing else and this late in the cycle is
always a bit touchy. It's kind of splitting hairs as it'll just get
backported, but post-rc8 is an odd spot to be in.
Is this actually manifesting as a crash for you?
Sorry I missed this last week.
> riscv_hartid_to_cpuid() instead of NR_CPUS. This is also
> aligned with all uses of riscv_hartid_to_cpuid() which
> expect negative error code upon failure.
> Fixes: 6825c7a80f18 ("RISC-V: Add logical CPU indexing for RISC-V")
Fixes: f99fb607fb2b ("RISC-V: Use Linux logical CPU number instead of hartid")
which is what actually manifests the bug -- again, kind of splitting
hairs as it's the patch after.
> Cc: stable at vger.kernel.org
> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> arch/riscv/kernel/smp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
> index ea028d9e0d24..d44567490d91 100644
> --- a/arch/riscv/kernel/smp.c
> +++ b/arch/riscv/kernel/smp.c
> @@ -54,7 +54,7 @@ int riscv_hartid_to_cpuid(int hartid)
> return i;
> pr_err("Couldn't find cpu id for hartid [%d]\n", hartid);
> - return i;
> + return -ENOENT;
> void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out)
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