Re: [PATCH] LoongArch: kexec_file: print out debugging message if required

[Qiang Ma]

在 2025/10/24 17:27, Youling Tang 写道:
> On 10/24/25 17:04, Qiang Ma wrote:
> > 在 2025/10/24 15:26, Youling Tang 写道:
> > > On 10/24/25 15:04, Huacai Chen wrote:
> > >
> > > > Hi, Youling,
> > > >
> > > > What do you think about this?
> > > >
> > > > Huacai
> > > >
> > > > On Tue, Oct 21, 2025 at 5:12 PM Qiang Ma <maqianga@xxxxxxxxxxxxx> 
> > > > wrote:
> > > > > When specifying '-d' for kexec_file_load interface, loaded locations
> > > > > of kernel/initrd/cmdline etc can be printed out to help debug.
> > >
> > > Although kexec_image_info() could be considered for removal in the 
> > > case of kexec_file,
> > > in the context of kexec_load, when using the -d parameter of 
> > > kexec-tools, although the
> > > userspace program outputs extensive debugging information, it is 
> > > recommended to retain
> > > this information during the debugging phase to verify the accuracy 
> > > of data transmission
> > > after it is passed into the kernel.
> > In the system call kexec_file_load(), after machine_kexec_prepare() 
> > is executed,
> >
> > there will be the same print information as the kexec_image_info(), 
> > and no modifications
> >
> > were made to the printed information during this period. Therefore, 
> > it can also verify
> >
> > the accuracy of the data, right?
>
>
> If only for kexec_file_load, we can directly remove kexec_image_info().
> But for kexec_load, I suggest keeping it.

I see.

But I think it's not necessary to add this print information to both

kexec_load and kexec_file_load. Just keep one.


Qiang.


> Youling.
> > Thanks,
> >
> > Qiang.
> >
> >
> > > Thanks,
> > > Youling.
> > > > > Commit eb7622d908a0 ("kexec_file, riscv: print out debugging message
> > > > > if required") fixes the same issue on RISC-V.
> > > > >
> > > > > So, remove kexec_image_info() because the content has been printed
> > > > > out in generic code.
> > > > >
> > > > > And on Loongson-3A5000, the printed messages look like below:
> > > > >
> > > > > [  288.667939] kexec_file: kernel: 00000000d9aad283 kernel_size: 
> > > > > 0x2e77f30
> > > > > [  288.668414] kexec_file(EFI): No LoongArch PE image header.
> > > > > [  288.703104] kexec_file: Loaded initrd at 0x80000000 
> > > > > bufsz=0x1637cd0 memsz=0x1638000
> > > > > [  288.703674] kexec_file(ELF): Loaded kernel at 0x9c20000 
> > > > > bufsz=0x27f1800 memsz=0x2950000
> > > > > [  288.704092] kexec_file: nr_segments = 2
> > > > > [  288.704277] kexec_file: segment[0]: buf=0x00000000cc3e6c33 
> > > > > bufsz=0x27f1800 mem=0x9c20000 memsz=0x2950000
> > > > > [  288.741213] kexec_file: segment[1]: buf=0x00000000bb75a541 
> > > > > bufsz=0x1637cd0 mem=0x80000000 memsz=0x1638000
> > > > > [  288.757182] kexec_file: kexec_file_load: type:0, 
> > > > > start:0xb15d000 head:0x18db60002 flags:0x8
> > > > >
> > > > > Signed-off-by: Qiang Ma <maqianga@xxxxxxxxxxxxx>
> > > > > ---
> > > > >   arch/loongarch/kernel/machine_kexec.c | 22 ----------------------
> > > > >   1 file changed, 22 deletions(-)
> > > > >
> > > > > diff --git a/arch/loongarch/kernel/machine_kexec.c 
> > > > > b/arch/loongarch/kernel/machine_kexec.c
> > > > > index e4b2bbc47e62..2d64b7c81e5e 100644
> > > > > --- a/arch/loongarch/kernel/machine_kexec.c
> > > > > +++ b/arch/loongarch/kernel/machine_kexec.c
> > > > > @@ -39,34 +39,12 @@ static unsigned long systable_ptr;
> > > > >   static unsigned long start_addr;
> > > > >   static unsigned long first_ind_entry;
> > > > >
> > > > > -static void kexec_image_info(const struct kimage *kimage)
> > > > > -{
> > > > > -       unsigned long i;
> > > > > -
> > > > > -       pr_debug("kexec kimage info:\n");
> > > > > -       pr_debug("\ttype:        %d\n", kimage->type);
> > > > > -       pr_debug("\tstart:       %lx\n", kimage->start);
> > > > > -       pr_debug("\thead:        %lx\n", kimage->head);
> > > > > -       pr_debug("\tnr_segments: %lu\n", kimage->nr_segments);
> > > > > -
> > > > > -       for (i = 0; i < kimage->nr_segments; i++) {
> > > > > -               pr_debug("\t    segment[%lu]: %016lx - %016lx", i,
> > > > > -                       kimage->segment[i].mem,
> > > > > -                       kimage->segment[i].mem + 
> > > > > kimage->segment[i].memsz);
> > > > > -               pr_debug("\t\t0x%lx bytes, %lu pages\n",
> > > > > -                       (unsigned long)kimage->segment[i].memsz,
> > > > > -                       (unsigned long)kimage->segment[i].memsz /  
> > > > > PAGE_SIZE);
> > > > > -       }
> > > > > -}
> > > > > -
> > > > >   int machine_kexec_prepare(struct kimage *kimage)
> > > > >   {
> > > > >          int i;
> > > > >          char *bootloader = "kexec";
> > > > >          void *cmdline_ptr = (void *)KEXEC_CMDLINE_ADDR;
> > > > >
> > > > > -       kexec_image_info(kimage);
> > > > > -
> > > > >          kimage->arch.efi_boot = fw_arg0;
> > > > >          kimage->arch.systable_ptr = fw_arg2;
> > > > >
> > > > > --
> > > > > 2.20.1