Re: [PATCHv2 1/2] kernel/kexec: Change the prototype of kimage_map_segment()

Baoquan He
2025-11-26T01:10:32Z

Hi Pingfan,

On 11/06/25 at 02:59pm, Pingfan Liu wrote:
> The kexec segment index will be required to extract the corresponding
> information for that segment in kimage_map_segment(). Additionally,
> kexec_segment already holds the kexec relocation destination address and
> size. Therefore, the prototype of kimage_map_segment() can be changed.

Because no cover letter, I just reply here.

I am testing code of (tag: next-20251125, next/master) on arm64 system.
I saw your two patches are already in there. When I used kexec reboot
as below, I still got the warning message during ima_kexec_post_load()
invocation.

====================
kexec -d -l /boot/vmlinuz-6.18.0-rc7-next-20251125 --initrd /boot/initramfs-6.18.0-rc7-next-20251125.img --reuse-cmdline
====================

====================
[34283.657670] kexec_file: kernel: 000000006cf71829 kernel_size: 0x48b0000
[34283.657700] PEFILE: Unsigned PE binary
[34283.676597] ima: kexec measurement buffer for the loaded kernel at 0xff206000.
[34283.676621] kexec_file: Loaded initrd at 0x84cb0000 bufsz=0x25ec426 memsz=0x25ed000
[34283.684646] kexec_file: Loaded dtb at 0xff400000 bufsz=0x39e memsz=0x1000
[34283.684653] kexec_file(Image): Loaded kernel at 0x80400000 bufsz=0x48b0000 memsz=0x48b0000
[34283.684663] kexec_file: nr_segments = 4
[34283.684666] kexec_file: segment[0]: buf=0x0000000000000000 bufsz=0x0 mem=0xff206000 memsz=0x1000
[34283.684674] kexec_file: segment[1]: buf=0x000000006cf71829 bufsz=0x48b0000 mem=0x80400000 memsz=0x48b0000
[34283.725987] kexec_file: segment[2]: buf=0x00000000c7369de6 bufsz=0x25ec426 mem=0x84cb0000 memsz=0x25ed000
[34283.747670] kexec_file: segmen
** replaying previous printk message **
[34283.747670] kexec_file: segment[3]: buf=0x00000000d83b530b bufsz=0x39e mem=0xff400000 memsz=0x1000
[34283.747973] ------------[ cut here ]------------
[34283.747976] WARNING: CPU: 33 PID: 16112 at kernel/kexec_core.c:1002 kimage_map_segment+0x138/0x190
[34283.778574] Modules linked in: rfkill vfat fat ipmi_ssif igb acpi_ipmi ipmi_si ipmi_devintf mlx5_fwctl i2c_algo_bit ipmi_msghandler fwctl fuse loop nfnetlink zram lz4hc_compress lz4_compress xfs mlx5_ib macsec mlx5_core nvme nvme_core mlxfw psample tls nvme_keyring nvme_auth pci_hyperv_intf sbsa_gwdt rpcrdma sunrpc rdma_ucm ib_uverbs ib_srpt ib_isert iscsi_target_mod target_core_mod ib_iser i2c_dev ib_umad rdma_cm ib_ipoib iw_cm ib_cm libiscsi ib_core scsi_transport_iscsi aes_neon_bs
[34283.824233] CPU: 33 UID: 0 PID: 16112 Comm: kexec Tainted: G W 6.17.8-200.fc42.aarch64 #1 PREEMPT(voluntary)
[34283.836355] Tainted: [W]=WARN
[34283.839684] Hardware name: CRAY CS500/CMUD , BIOS 1.4.0 Jun 17 2020
[34283.846903] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[34283.854243] pc : kimage_map_segment+0x138/0x190
[34283.859120] lr : kimage_map_segment+0x4c/0x190
[34283.863920] sp : ffff8000a0643a90
[34283.867394] x29: ffff8000a0643a90 x28: ffff800083d0a000 x27: 0000000000000000
[34283.874901] x26: 0000aaaad722d4b0 x25: 000000000000008f x24: ffff800083d0a000
[34283.882608] x23: 0000000000000001 x22: 00000000ff206000 x21: 00000000ff207000
[34283.890305] x20: ffff008fbd306980 x19: ffff008f895d6400 x18: 00000000fffffff9
[34283.897815] x17: 303d6d656d206539 x16: 3378303d7a736675 x15: 646565732d676e72
[34283.905516] x14: 00646565732d726c x13: 616d692c78756e69 x12: 6c00636578656b2d
[34283.912999] x11: 007265666675622d x10: 636578656b2d616d x9 : ffff80008050b73c
[34283.920691] x8 : 0001000000000000 x7 : 0000000000000000 x6 : 0000000080000000
[34283.928197] x5 : 0000000084cb0000 x4 : ffff008fbd2306b0 x3 : ffff008fbd305000
[34283.935898] x2 : fffffff7ff000000 x1 : 0000000000000004 x0 : ffff800082046000
[34283.943603] Call trace:
[34283.946039] kimage_map_segment+0x138/0x190 (P)
[34283.950935] ima_kexec_post_load+0x58/0xc0
[34283.955225] __do_sys_kexec_file_load+0x2b8/0x398
[34283.960279] __arm64_sys_kexec_file_load+0x28/0x40
[34283.965965] invoke_syscall.constprop.0+0x64/0xe8
[34283.971025] el0_svc_common.constprop.0+0x40/0xe8
[34283.975883] do_el0_svc+0x24/0x38
[34283.979361] el0_svc+0x3c/0x168
[34283.982833] el0t_64_sync_handler+0xa0/0xf0
[34283.987176] el0t_64_sync+0x1b0/0x1b8
[34283.991000] ---[ end trace 0000000000000000 ]---
[34283.996060] ------------[ cut here ]------------
[34283.996064] WARNING: CPU: 33 PID: 16112 at mm/vmalloc.c:538 vmap_pages_pte_range+0x2bc/0x3c0
[34284.010006] Modules linked in: rfkill vfat fat ipmi_ssif igb acpi_ipmi ipmi_si ipmi_devintf mlx5_fwctl i2c_algo_bit ipmi_msghandler fwctl fuse loop nfnetlink zram lz4hc_compress lz4_compress xfs mlx5_ib macsec mlx5_core nvme nvme_core mlxfw psample tls nvme_keyring nvme_auth pci_hyperv_intf sbsa_gwdt rpcrdma sunrpc rdma_ucm ib_uverbs ib_srpt ib_isert iscsi_target_mod target_core_mod ib_iser i2c_dev ib_umad rdma_cm ib_ipoib iw_cm ib_cm libiscsi ib_core scsi_transport_iscsi aes_neon_bs
[34284.055630] CPU: 33 UID: 0 PID: 16112 Comm: kexec Tainted: G W 6.17.8-200.fc42.aarch64 #1 PREEMPT(voluntary)
[34284.067701] Tainted: [W]=WARN
[34284.070833] Hardware name: CRAY CS500/CMUD , BIOS 1.4.0 Jun 17 2020
[34284.078238] pstate: 40400009 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[34284.085546] pc : vmap_pages_pte_range+0x2bc/0x3c0
[34284.090607] lr : vmap_small_pages_range_noflush+0x16c/0x298
[34284.096528] sp : ffff8000a0643940
[34284.100001] x29: ffff8000a0643940 x28: 0000000000000000 x27: ffff800084f76000
[34284.107699] x26: fffffdffc0000000 x25: ffff8000a06439d0 x24: ffff800082046000
[34284.115174] x23: ffff800084f75000 x22: ffff007f80337ba8 x21: 03ffffffffffffc0
[34284.122821] x20: ffff008fbd306980 x19: ffff8000a06439d4 x18: 00000000fffffff9
[34284.130331] x17: 303d6d656d206539 x16: 3378303d7a736675 x15: 646565732d676e72
[34284.138032] x14: 0000000000004000 x13: ffff009781307130 x12: 0000000000002000
[34284.145733] x11: 0000000000000000 x10: 0000000000000001 x9 : ffff8000804e197c
[34284.153248] x8 : 0000000000000027 x7 : ffff800085175000 x6 : ffff8000a06439d4
[34284.160944] x5 : ffff8000a06439d0 x4 : ffff008fbd306980 x3 : 0068000000000f03
[34284.168449] x2 : ffff007f80337ba8 x1 : 0000000000000000 x0 : 0000000000000000
[34284.176150] Call trace:
[34284.178768] vmap_pages_pte_range+0x2bc/0x3c0 (P)
[34284.183665] vmap_small_pages_range_noflush+0x16c/0x298
[34284.189264] vmap+0xb4/0x138
[34284.192312] kimage_map_segment+0xdc/0x190
[34284.196794] ima_kexec_post_load+0x58/0xc0
[34284.201044] __do_sys_kexec_file_load+0x2b8/0x398
[34284.206107] __arm64_sys_kexec_file_load+0x28/0x40
[34284.211254] invoke_syscall.constprop.0+0x64/0xe8
[34284.216139] el0_svc_common.constprop.0+0x40/0xe8
[34284.221196] do_el0_svc+0x24/0x38
[34284.224678] el0_svc+0x3c/0x168
[34284.227983] el0t_64_sync_handler+0xa0/0xf0
[34284.232526] el0t_64_sync+0x1b0/0x1b8
[34284.236376] ---[ end trace 0000000000000000 ]---
[34284.241412] kexec_core: Could not map ima buffer.
[34284.241421] ima: Could not map measurements buffer.
[34284.551336] machine_kexec_post_load:155:
[34284.551354] kexec kimage info:
[34284.551366] type: 0
[34284.551373] head: 90363f9002
[34284.551377] kern_reloc: 0x00000090363f7000
[34284.551381] el2_vectors: 0x0000000000000000
[34284.551384] kexec_file: kexec_file_load: type:0, start:0x80400000 head:0x90363f9002 flags:0x8
====================

>
> Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation")
> Signed-off-by: Pingfan Liu <piliu@redhat.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Baoquan He <bhe@redhat.com>
> Cc: Mimi Zohar <zohar@linux.ibm.com>
> Cc: Roberto Sassu <roberto.sassu@huawei.com>
> Cc: Alexander Graf <graf@amazon.com>
> Cc: Steven Chen <chenste@linux.microsoft.com>
> Cc: <stable@vger.kernel.org>
> To: kexec@lists.infradead.org
> To: linux-integrity@vger.kernel.org
> ---
> include/linux/kexec.h | 4 ++--
> kernel/kexec_core.c | 9 ++++++---
> security/integrity/ima/ima_kexec.c | 4 +---
> 3 files changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index ff7e231b0485..8a22bc9b8c6c 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -530,7 +530,7 @@ extern bool kexec_file_dbg_print;
> #define kexec_dprintk(fmt, arg...) \
> do { if (kexec_file_dbg_print) pr_info(fmt, ##arg); } while (0)
>
> -extern void *kimage_map_segment(struct kimage *image, unsigned long addr, unsigned long size);
> +extern void *kimage_map_segment(struct kimage *image, int idx);
> extern void kimage_unmap_segment(void *buffer);
> #else /* !CONFIG_KEXEC_CORE */
> struct pt_regs;
> @@ -540,7 +540,7 @@ static inline void __crash_kexec(struct pt_regs *regs) { }
> static inline void crash_kexec(struct pt_regs *regs) { }
> static inline int kexec_should_crash(struct task_struct *p) { return 0; }
> static inline int kexec_crash_loaded(void) { return 0; }
> -static inline void *kimage_map_segment(struct kimage *image, unsigned long addr, unsigned long size)
> +static inline void *kimage_map_segment(struct kimage *image, int idx)
> { return NULL; }
> static inline void kimage_unmap_segment(void *buffer) { }
> #define kexec_in_progress false
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index fa00b239c5d9..9a1966207041 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -960,17 +960,20 @@ int kimage_load_segment(struct kimage *image, int idx)
> return result;
> }
>
> -void *kimage_map_segment(struct kimage *image,
> - unsigned long addr, unsigned long size)
> +void *kimage_map_segment(struct kimage *image, int idx)
> {
> + unsigned long addr, size, eaddr;
> unsigned long src_page_addr, dest_page_addr = 0;
> - unsigned long eaddr = addr + size;
> kimage_entry_t *ptr, entry;
> struct page **src_pages;
> unsigned int npages;
> void *vaddr = NULL;
> int i;
>
> + addr = image->segment[idx].mem;
> + size = image->segment[idx].memsz;
> + eaddr = addr + size;
> +
> /*
> * Collect the source pages and map them in a contiguous VA range.
> */
> diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
> index 7362f68f2d8b..5beb69edd12f 100644
> --- a/security/integrity/ima/ima_kexec.c
> +++ b/security/integrity/ima/ima_kexec.c
> @@ -250,9 +250,7 @@ void ima_kexec_post_load(struct kimage *image)
> if (!image->ima_buffer_addr)
> return;
>
> - ima_kexec_buffer = kimage_map_segment(image,
> - image->ima_buffer_addr,
> - image->ima_buffer_size);
> + ima_kexec_buffer = kimage_map_segment(image, image->ima_segment_index);
> if (!ima_kexec_buffer) {
> pr_err("Could not map measurements buffer.\n");
> return;
> --
> 2.49.0
>