Apologize for late reply, I'm occupied with something else.

On 08/10/18 at 07:39pm, Mike Galbraith wrote:
> On Fri, 2018-08-10 at 18:28 +0800, Dave Young wrote:
> > 
> > > @@ -250,8 +253,10 @@ setup_boot_parameters(struct kimage *image, struct 
> > > boot_params *params,
> > >  
> > >  #ifdef CONFIG_EFI
> > >   /* Setup EFI state */
> > > - setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
> > > + ret = setup_efi_state(params, params_load_addr, efi_map_offset, 
> > > efi_map_sz,
> > >                   efi_setup_data_offset);
> > > + if (ret)
> > 
> > Here should check efi_enabled(EFI_BOOT) && ret
> 
> Patch with that works for me.
> 
> > In case efi boot we need the efi info set correctly,  or one need pass
> > acpi_rsdp= in kernel cmdline param.
> > 
> > Still not sure how to allow one to workaround it by using acpi_rsdp=
> > param with kexec_file_load..
> 
> Does this improve things, and plug the no boot hole?

Would you mind to tune my patch with some acpi_rsdp checking and add
some error message in case kexec load failure? Eg. suggest people to use
append acpi_rsdp for noefi booting etc.

I'm still not very satisfied with the code cleanup, ideally we should add a
separate kbuf for efi stuff, so that we can isolate the efi_map_sz
efi_setup_data_offset, and efi_map_offset initialization only when
necessary.  Anyway the cleanup can be a separate patch.

> 
> x86, kdump: cleanup efi setup data handling a bit
> 
> 1. Remove efi specific variables from bzImage64_load() other than the
> one it needs, efi_map_sz, passing it and params_cmdline_sz on to efi
> setup functions, giving them all they need without duplication.
> 
> 2. Only allocate space for efi setup data when a 1:1 mapping is available.
> Bail early with -ENODEV if not available, but is required to boot, and
> acpi_rsdp= was not passed on the command line. 
> 
> 3. Use the proper config dependency to isolate efi setup functions,
> adding a !EFI_RUNTIME_MAP stub for setup_efi_state().
> 
> 4. Change efi functions that cannot fail to void. 
> 
> Signed-off-by: Mike Galbraith <efa...@gmx.de>
> ---
>  arch/x86/kernel/kexec-bzimage64.c |   99 
> +++++++++++++++++---------------------
>  1 file changed, 45 insertions(+), 54 deletions(-)
> 
> --- a/arch/x86/kernel/kexec-bzimage64.c
> +++ b/arch/x86/kernel/kexec-bzimage64.c
> @@ -112,35 +112,32 @@ static int setup_e820_entries(struct boo
>       return 0;
>  }
>  
> -#ifdef CONFIG_EFI
> -static int setup_efi_info_memmap(struct boot_params *params,
> +#ifdef CONFIG_EFI_RUNTIME_MAP
> +static void setup_efi_info_memmap(struct boot_params *params,
>                                 unsigned long params_load_addr,
> -                               unsigned int efi_map_offset,
> +                               unsigned int params_cmdline_sz,
>                                 unsigned int efi_map_sz)
>  {
> -     void *efi_map = (void *)params + efi_map_offset;
> -     unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
> +     void *efi_map = (void *)params + params_cmdline_sz;
> +     unsigned long efi_map_phys_addr = params_load_addr + params_cmdline_sz;
>       struct efi_info *ei = &params->efi_info;
>  
> -     if (!efi_map_sz)
> -             return -EINVAL;
> -
>       efi_runtime_map_copy(efi_map, efi_map_sz);
>  
>       ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
>       ei->efi_memmap_hi = efi_map_phys_addr >> 32;
>       ei->efi_memmap_size = efi_map_sz;
> -
> -     return 0;
>  }
>  
> -static int
> +static void
>  prepare_add_efi_setup_data(struct boot_params *params,
> -                    unsigned long params_load_addr,
> -                    unsigned int efi_setup_data_offset)
> +                        unsigned long params_load_addr,
> +                        unsigned int params_cmdline_sz,
> +                        unsigned int efi_map_sz)
>  {
> +     unsigned int data_offset = params_cmdline_sz + ALIGN(efi_map_sz, 16);
>       unsigned long setup_data_phys;
> -     struct setup_data *sd = (void *)params + efi_setup_data_offset;
> +     struct setup_data *sd = (void *)params + data_offset;
>       struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
>  
>       esd->fw_vendor = efi.fw_vendor;
> @@ -152,33 +149,20 @@ prepare_add_efi_setup_data(struct boot_p
>       sd->len = sizeof(struct efi_setup_data);
>  
>       /* Add setup data */
> -     setup_data_phys = params_load_addr + efi_setup_data_offset;
> +     setup_data_phys = params_load_addr + data_offset;
>       sd->next = params->hdr.setup_data;
>       params->hdr.setup_data = setup_data_phys;
> -
> -     return 0;
>  }
>  
>  static int
>  setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
> -             unsigned int efi_map_offset, unsigned int efi_map_sz,
> -             unsigned int efi_setup_data_offset)
> +             unsigned int params_cmdline_sz, unsigned int efi_map_sz)
>  {
>       struct efi_info *current_ei = &boot_params.efi_info;
>       struct efi_info *ei = &params->efi_info;
> -     int ret;
> -
> -     if (!current_ei->efi_memmap_size)
> -             return -EINVAL;
>  
> -     /*
> -      * If 1:1 mapping is not enabled, second kernel can not setup EFI
> -      * and use EFI run time services. User space will have to pass
> -      * acpi_rsdp=<addr> on kernel command line to make second kernel boot
> -      * without efi.
> -      */
> -     if (efi_enabled(EFI_OLD_MEMMAP) || !efi_enabled(EFI_RUNTIME_SERVICES))
> -             return -ENODEV;
> +     if (!efi_map_sz || !current_ei->efi_memmap_size)
> +             return efi_map_sz ? -EINVAL : 0;
>  
>       ei->efi_loader_signature = current_ei->efi_loader_signature;
>       ei->efi_systab = current_ei->efi_systab;
> @@ -187,21 +171,24 @@ setup_efi_state(struct boot_params *para
>       ei->efi_memdesc_version = current_ei->efi_memdesc_version;
>       ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
>  
> -     ret = setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
> +     setup_efi_info_memmap(params, params_load_addr, params_cmdline_sz,
>                             efi_map_sz);
> -     if (ret)
> -             return ret;
> -     prepare_add_efi_setup_data(params, params_load_addr,
> -                                efi_setup_data_offset);
> +     prepare_add_efi_setup_data(params, params_load_addr, params_cmdline_sz,
> +                                efi_map_sz);
>       return 0;
>  }
> -#endif /* CONFIG_EFI */
> +#else /* !CONFIG_EFI_RUNTIME_MAP */
> +static int
> +setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
> +             unsigned int params_cmdline_sz, unsigned int efi_map_sz)
> +{ return 0; }
> +#endif /* CONFIG_EFI_RUNTIME_MAP */
>  
>  static int
>  setup_boot_parameters(struct kimage *image, struct boot_params *params,
>                     unsigned long params_load_addr,
> -                   unsigned int efi_map_offset, unsigned int efi_map_sz,
> -                   unsigned int efi_setup_data_offset)
> +                   unsigned int params_cmdline_sz,
> +                   unsigned int efi_map_sz)
>  {
>       unsigned int nr_e820_entries;
>       unsigned long long mem_k, start, end;
> @@ -251,13 +238,9 @@ setup_boot_parameters(struct kimage *ima
>               }
>       }
>  
> -#ifdef CONFIG_EFI
> -     /* Setup EFI state */
> -     ret = setup_efi_state(params, params_load_addr, efi_map_offset, 
> efi_map_sz,
> -                     efi_setup_data_offset);
> -     if (efi_enabled(EFI_BOOT) && ret)
> +     ret = setup_efi_state(params, params_load_addr, params_cmdline_sz, 
> efi_map_sz);
> +     if (ret)
>               return ret;
> -#endif
>  
>       /* Setup EDD info */
>       memcpy(params->eddbuf, boot_params.eddbuf,
> @@ -343,7 +326,7 @@ static void *bzImage64_load(struct kimag
>       struct kexec_entry64_regs regs64;
>       void *stack;
>       unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
> -     unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
> +     unsigned int efi_map_sz = 0;
>       struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
>                                 .top_down = true };
>       struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR,
> @@ -402,19 +385,28 @@ static void *bzImage64_load(struct kimag
>        * have to create separate segment for each. Keeps things
>        * little bit simple
>        */
> -     efi_map_sz = efi_get_runtime_map_size();
>       params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
>                               MAX_ELFCOREHDR_STR_LEN;
>       params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
> -     kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
> -                             sizeof(struct setup_data) +
> -                             sizeof(struct efi_setup_data);
> +     kbuf.bufsz = params_cmdline_sz + sizeof(struct setup_data);
> +
> +     /*
> +      * If a 1:1 mapping does not exist, the second kernel cannot setup
> +      * and use EFI run time services, user space will have to pass
> +      * acpi_rsdp=<addr> on the kernel command line to make the second
> +      * kernel boot without efi.  Allocate space for efi setup data if
> +      * this constraint is met, bail if not, but is required to boot,
> +      * and acpi_rsdp=<addr> was not passed on the command line.
> +      */
> +     if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_OLD_MEMMAP)) {
> +             efi_map_sz = efi_get_runtime_map_size();
> +             kbuf.bufsz += ALIGN(efi_map_sz, 16) + sizeof(struct 
> efi_setup_data);
> +     } else if (efi_enabled(EFI_BOOT) && !strstr(cmdline, "acpi_rsdp="))
> +             return ERR_PTR(-ENODEV);
>  
>       params = kzalloc(kbuf.bufsz, GFP_KERNEL);
>       if (!params)
>               return ERR_PTR(-ENOMEM);
> -     efi_map_offset = params_cmdline_sz;
> -     efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
>  
>       /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
>       setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
> @@ -494,8 +486,7 @@ static void *bzImage64_load(struct kimag
>               goto out_free_params;
>  
>       ret = setup_boot_parameters(image, params, bootparam_load_addr,
> -                                 efi_map_offset, efi_map_sz,
> -                                 efi_setup_data_offset);
> +                                 params_cmdline_sz, efi_map_sz);
>       if (ret)
>               goto out_free_params;
>  
> 

Thanks
Dave

Reply via email to