[PATCH v3 0/2] two fixes in kho_populate()

[PATCH v3 0/2] two fixes in kho_populate()

[ranxiaokai627]

From: Ran Xiaokai <ran.xiaokai@zte.com.cn>

Patch1 fixes unpaired call of early_memmap()/early_memunmap()
Patch2 cleans up unnecessary call of WARN_ON()

v3
 - rename all the labels suggested by Pratyush

v2
 - Improve code readability suggested by Pratyush
 - collect reviewed-by
 
Ran Xiaokai (2):
  kho: fix missing early_memunmap() call in kho_populate()
  kho: remove unnecessary WARN_ON(err) in kho_populate()

 kernel/liveupdate/kexec_handover.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

-- 
2.25.1

[PATCH v3 1/2] kho: fix missing early_memunmap() call in kho_populate()

[ranxiaokai627]

From: Ran Xiaokai <ran.xiaokai@zte.com.cn>

kho_populate() returns without calling early_memunmap() on success
path, this will cause early ioremap virtual address space leak.

Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
---
 kernel/liveupdate/kexec_handover.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index fb3a7b67676e..af82d8862dd7 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -1463,36 +1463,37 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 	struct kho_scratch *scratch = NULL;
 	phys_addr_t mem_map_phys;
 	void *fdt = NULL;
+	bool populated = false;
 	int err;
 
 	/* Validate the input FDT */
 	fdt = early_memremap(fdt_phys, fdt_len);
 	if (!fdt) {
 		pr_warn("setup: failed to memremap FDT (0x%llx)\n", fdt_phys);
-		goto err_report;
+		goto report;
 	}
 	err = fdt_check_header(fdt);
 	if (err) {
 		pr_warn("setup: handover FDT (0x%llx) is invalid: %d\n",
 			fdt_phys, err);
-		goto err_unmap_fdt;
+		goto unmap_fdt;
 	}
 	err = fdt_node_check_compatible(fdt, 0, KHO_FDT_COMPATIBLE);
 	if (err) {
 		pr_warn("setup: handover FDT (0x%llx) is incompatible with '%s': %d\n",
 			fdt_phys, KHO_FDT_COMPATIBLE, err);
-		goto err_unmap_fdt;
+		goto unmap_fdt;
 	}
 
 	mem_map_phys = kho_get_mem_map_phys(fdt);
 	if (!mem_map_phys)
-		goto err_unmap_fdt;
+		goto unmap_fdt;
 
 	scratch = early_memremap(scratch_phys, scratch_len);
 	if (!scratch) {
 		pr_warn("setup: failed to memremap scratch (phys=0x%llx, len=%lld)\n",
 			scratch_phys, scratch_len);
-		goto err_unmap_fdt;
+		goto unmap_fdt;
 	}
 
 	/*
@@ -1509,7 +1510,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 		if (WARN_ON(err)) {
 			pr_warn("failed to mark the scratch region 0x%pa+0x%pa: %pe",
 				&area->addr, &size, ERR_PTR(err));
-			goto err_unmap_scratch;
+			goto unmap_scratch;
 		}
 		pr_debug("Marked 0x%pa+0x%pa as scratch", &area->addr, &size);
 	}
@@ -1529,16 +1530,17 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 	kho_in.scratch_phys = scratch_phys;
 	kho_in.mem_map_phys = mem_map_phys;
 	kho_scratch_cnt = scratch_cnt;
-	pr_info("found kexec handover data.\n");
 
-	return;
+	populated = true;
+	pr_info("found kexec handover data.\n");
 
-err_unmap_scratch:
+unmap_scratch:
 	early_memunmap(scratch, scratch_len);
-err_unmap_fdt:
+unmap_fdt:
 	early_memunmap(fdt, fdt_len);
-err_report:
-	pr_warn("disabling KHO revival\n");
+report:
+	if (!populated)
+		pr_warn("disabling KHO revival\n");
 }
 
 /* Helper functions for kexec_file_load */
-- 
2.25.1

Re: [PATCH v3 1/2] kho: fix missing early_memunmap() call in kho_populate()

[Pratyush Yadav]

On Thu, Feb 12 2026, ranxiaokai627@163.com wrote:

> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>
> kho_populate() returns without calling early_memunmap() on success
> path, this will cause early ioremap virtual address space leak.
>
> Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>

Thanks.

Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

[...]

-- 
Regards,
Pratyush Yadav

[PATCH v3 2/2] kho: remove unnecessary WARN_ON(err) in kho_populate()

[ranxiaokai627]

From: Ran Xiaokai <ran.xiaokai@zte.com.cn>

The following pr_warn() provides detailed error and location
information, WARN_ON(err) adds no additional debugging value,
so remove the redundant WARN_ON() call.

Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 kernel/liveupdate/kexec_handover.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index af82d8862dd7..95601623b4d6 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -1507,7 +1507,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 
 		memblock_add(area->addr, size);
 		err = memblock_mark_kho_scratch(area->addr, size);
-		if (WARN_ON(err)) {
+		if (err) {
 			pr_warn("failed to mark the scratch region 0x%pa+0x%pa: %pe",
 				&area->addr, &size, ERR_PTR(err));
 			goto unmap_scratch;
-- 
2.25.1