From: Mukesh Pilaniya <mpilaniy@redhat.com>
To: "Mike Rapoport (Microsoft)" <rppt@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Pasha Tatashin <pasha.tatashin@soleen.com>,
Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>,
Andrew Morton <akpm@linux-foundation.org>,
Chen Pei <cp0613@linux.alibaba.com>,
George Guo <guodongtai@kylinos.cn>,
Kexin Liu <liukexin@kylinos.cn>,
Randy Dunlap <rdunlap@infradead.org>,
Shuah Khan <skhan@linuxfoundation.org>,
Sourabh Jain <sourabhjain@linux.ibm.com>,
kexec@lists.infradead.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v3 1/5] kho: reject zero bootmem scale
Date: Fri, 13 Nov 2026 22:36:30 +0530 [thread overview]
Message-ID: <2bae83be-bb44-4541-bf1c-5861f73a7394@redhat.com> (raw)
In-Reply-To: <20261112-kho-bootmem-sizing-v3-1-f0c8d00295d5@kernel.org>
On 12/11/26 4:08 pm, Mike Rapoport (Microsoft) wrote:
> kho_bootmem=0% sets bootmem_scale to 0, and then the bootmem areas are
> sized using the explicit sizes that default to 0. KHO remains enabled,
> but there is no usable bootmem to load the next kernel.
>
> Reject zero scale the same way zero explicit sizes are rejected.
>
> Fixes: 3dc92c311498 ("kexec: add Kexec HandOver (KHO) generation helpers")
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> kernel/liveupdate/kexec_handover.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index 6f1f55fe31819..b30ba686cb301 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -703,16 +703,22 @@ static int __init kho_parse_bootmem_size(char *p)
> if (p[len - 1] == '%') {
> /* unsigned int max is 4,294,967,295, 10 chars */
> char s_scale[11] = {};
> + unsigned int scale;
> int ret = 0;
>
> if (len > ARRAY_SIZE(s_scale))
> return -EINVAL;
>
> memcpy(s_scale, p, len - 1);
> - ret = kstrtouint(s_scale, 10, &bootmem_scale);
> - if (!ret)
> - pr_notice("bootmem scale is %d%%\n", bootmem_scale);
> - return ret;
> + ret = kstrtouint(s_scale, 10, &scale);
> + if (ret)
> + return ret;
> + if (!scale)
> + return -EINVAL;
Reviewed-by: Mukesh Pilaniya <mpilaniy@redhat.com>
> +
> + bootmem_scale = scale;
> + pr_notice("bootmem scale is %d%%\n", bootmem_scale);
> + return 0;
> }
>
> /* parse ll[KMG],mm[KMG],nn[KMG] */
>
--
Regards,
Mukesh Pilaniya
next prev parent reply other threads:[~2026-11-13 17:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-12 10:38 [PATCH v3 0/5] kho: fix bootmem sizing Mike Rapoport (Microsoft)
2026-11-12 10:38 ` [PATCH v3 1/5] kho: reject zero bootmem scale Mike Rapoport (Microsoft)
2026-11-12 13:30 ` Pratyush Yadav
2026-11-12 14:59 ` Pasha Tatashin
2026-11-13 17:06 ` Mukesh Pilaniya [this message]
2026-11-12 10:38 ` [PATCH v3 2/5] kho: walk bootmem areas in address order Mike Rapoport (Microsoft)
2026-11-12 10:38 ` [PATCH v3 3/5] kho: skip zero-sized lowmem and global bootmem areas Mike Rapoport (Microsoft)
2026-11-12 10:38 ` [PATCH v3 4/5] kho: fix bootmem sizing Mike Rapoport (Microsoft)
2026-11-12 10:38 ` [PATCH v3 5/5] kho: docs: update description of bootmem regions Mike Rapoport (Microsoft)
2026-11-12 13:48 ` Pratyush Yadav
2026-11-12 15:00 ` Pasha Tatashin
2026-11-13 17:22 ` Mukesh Pilaniya
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