Message-ID: <dfc3e30e47a37f6386dc26d46814ae12@ispras.ru>
Date:   Thu, 09 Mar 2023 20:22:43 +0300
From:   Evgeniy Baskov <baskov@...ras.ru>
To:     Ard Biesheuvel <ardb@...nel.org>
Cc:     Borislav Petkov <bp@...en8.de>, Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Alexey Khoroshilov <khoroshilov@...ras.ru>,
        Peter Jones <pjones@...hat.com>,
        "Limonciello, Mario" <mario.limonciello@....com>,
        joeyli <jlee@...e.com>, lvc-project@...uxtesting.org,
        x86@...nel.org, linux-efi@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org
Subject: Re: [PATCH v4 19/26] x86/build: Cleanup tools/build.c

On 2023-03-09 19:50, Ard Biesheuvel wrote:
> On Thu, 9 Mar 2023 at 17:25, Evgeniy Baskov <baskov@...ras.ru> wrote:
>> 
>> On 2023-03-09 18:57, Ard Biesheuvel wrote:
>> > On Thu, 15 Dec 2022 at 13:42, Evgeniy Baskov <baskov@...ras.ru> wrote:
>> >>
>> >> Use newer C standard. Since kernel requires C99 compiler now,
>> >> we can make use of the new features to make the core more readable.
>> >>
>> >> Use mmap() for reading files also to make things simpler.
>> >>
>> >> Replace most magic numbers with defines.
>> >>
>> >> Should have no functional changes. This is done in preparation for the
>> >> next changes that makes generated PE header more spec compliant.
>> >>
>> >> Tested-by: Mario Limonciello <mario.limonciello@....com>
>> >> Tested-by: Peter Jones <pjones@...hat.com>
>> >> Signed-off-by: Evgeniy Baskov <baskov@...ras.ru>
>> >> ---
>> >>  arch/x86/boot/tools/build.c | 387
>> >> +++++++++++++++++++++++-------------
>> >>  1 file changed, 245 insertions(+), 142 deletions(-)
>> >>
>> >> diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
>> >> index bd247692b701..fbc5315af032 100644
>> >> --- a/arch/x86/boot/tools/build.c
>> >> +++ b/arch/x86/boot/tools/build.c
>> >> @@ -25,20 +25,21 @@
>> >>   * Substantially overhauled by H. Peter Anvin, April 2007
>> >>   */
>> >>
>> >> +#include <fcntl.h>
>> >> +#include <stdarg.h>
>> >> +#include <stdint.h>
>> >>  #include <stdio.h>
>> >> -#include <string.h>
>> >>  #include <stdlib.h>
>> >> -#include <stdarg.h>
>> >> -#include <sys/types.h>
>> >> +#include <string.h>
>> >> +#include <sys/mman.h>
>> >>  #include <sys/stat.h>
>> >> +#include <sys/types.h>
>> >>  #include <unistd.h>
>> >> -#include <fcntl.h>
>> >> -#include <sys/mman.h>
>> >> +
>> >>  #include <tools/le_byteshift.h>
>> >> +#include <linux/pe.h>
>> >>
>> >> -typedef unsigned char  u8;
>> >> -typedef unsigned short u16;
>> >> -typedef unsigned int   u32;
>> >> +#define round_up(x, n) (((x) + (n) - 1) & ~((n) - 1))
>> >>
>> >>  #define DEFAULT_MAJOR_ROOT 0
>> >>  #define DEFAULT_MINOR_ROOT 0
>> >> @@ -48,8 +49,13 @@ typedef unsigned int   u32;
>> >>  #define SETUP_SECT_MIN 5
>> >>  #define SETUP_SECT_MAX 64
>> >>
>> >> +#define PARAGRAPH_SIZE 16
>> >> +#define SECTOR_SIZE 512
>> >> +#define FILE_ALIGNMENT 512
>> >> +#define SECTION_ALIGNMENT 4096
>> >> +
>> >>  /* This must be large enough to hold the entire setup */
>> >> -u8 buf[SETUP_SECT_MAX*512];
>> >> +uint8_t buf[SETUP_SECT_MAX*SECTOR_SIZE];
>> >>
>> >>  #define PECOFF_RELOC_RESERVE 0x20
>> >>
>> >> @@ -59,6 +65,52 @@ u8 buf[SETUP_SECT_MAX*512];
>> >>  #define PECOFF_COMPAT_RESERVE 0x0
>> >>  #endif
>> >>
>> >> +#define RELOC_SECTION_SIZE 10
>> >> +
>> >> +/* PE header has different format depending on the architecture */
>> >> +#ifdef CONFIG_X86_64
>> >> +typedef struct pe32plus_opt_hdr pe_opt_hdr;
>> >> +#else
>> >> +typedef struct pe32_opt_hdr pe_opt_hdr;
>> >> +#endif
>> >> +
>> >> +static inline struct pe_hdr *get_pe_header(uint8_t *buf)
>> >> +{
>> >> +       uint32_t pe_offset =
>> >> get_unaligned_le32(buf+MZ_HEADER_PEADDR_OFFSET);
>> >> +       return (struct pe_hdr *)(buf + pe_offset);
>> >> +}
>> >> +
>> >> +static inline pe_opt_hdr *get_pe_opt_header(uint8_t *buf)
>> >> +{
>> >> +       return (pe_opt_hdr *)(get_pe_header(buf) + 1);
>> >> +}
>> >> +
>> >> +static inline struct section_header *get_sections(uint8_t *buf)
>> >> +{
>> >> +       pe_opt_hdr *hdr = get_pe_opt_header(buf);
>> >> +       uint32_t n_data_dirs = get_unaligned_le32(&hdr->data_dirs);
>> >> +       uint8_t *sections = (uint8_t *)(hdr + 1) +
>> >> n_data_dirs*sizeof(struct data_dirent);
>> >> +       return  (struct section_header *)sections;
>> >> +}
>> >> +
>> >> +static inline struct data_directory *get_data_dirs(uint8_t *buf)
>> >> +{
>> >> +       pe_opt_hdr *hdr = get_pe_opt_header(buf);
>> >> +       return (struct data_directory *)(hdr + 1);
>> >> +}
>> >> +
>> >> +#ifdef CONFIG_EFI_DXE_MEM_ATTRIBUTES
>> >
>> > Can we drop this conditional?
>> 
>> Without CONFIG_EFI_DXE_MEM_ATTRIBUTES memory attributes are not
>> getting applies anywhere, so this would break 'nokaslr' on UEFI
>> implementations that honor section attributes.
>> 
> 
> How so? This only affects the mappings that are created by UEFI for
> the decompressor binary, right?

I was thinking about the in-place decompression, but now I've realized
that I was wrong since in-place decompression cannot happen when booting
via the stub. I'll remove the ifdef.

> 
>> KASLR is already broken without that option on implementations
>> that disallow execution of the free memory though. But unlike
>> free memory, sections are more likely to get protected, I think.
>> 
> 
> We need to allocate those pages properly in any case (see my other
> reply) so it is no longer free memory.

It should be fine, as I explained.

The only thing that is a little unexpected is that the kernel might
shift even with 'nokaslr' when the LOAD_PHYSICAL_ADDR is already taken
by some firmware allocation (or by us). This should cause no real
problems, since the kernel is required to be relocatable for the 
EFISTUB.

> 
>> >> +#define SCN_RW (IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE |
>> >> IMAGE_SCN_ALIGN_4096BYTES)
>> >> +#define SCN_RX (IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_EXECUTE |
>> >> IMAGE_SCN_ALIGN_4096BYTES)
>> >> +#define SCN_RO (IMAGE_SCN_MEM_READ | IMAGE_SCN_ALIGN_4096BYTES)
>> >
>> > Please drop the alignment flags - they don't apply to executable only
>> > object files.
>> 
>> Got it, will remove them in v5.
>> 
>> >
>> >> +#else
>> >> +/* With memory protection disabled all sections are RWX */
>> >> +#define SCN_RW (IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE | \
>> >> +               IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_ALIGN_4096BYTES)
>> >> +#define SCN_RX SCN_RW
>> >> +#define SCN_RO SCN_RW
>> >> +#endif
>> >> +
>> >>  static unsigned long efi32_stub_entry;
>> >>  static unsigned long efi64_stub_entry;
>> >>  static unsigned long efi_pe_entry;
>> >> @@ -70,7 +122,7 @@ static unsigned long _end;
>> >>
>> >>
>> >> /*----------------------------------------------------------------------*/
>> >>
>> >> -static const u32 crctab32[] = {
>> >> +static const uint32_t crctab32[] = {
>> >
>> > Replacing all the type names makes this patch very messy. Can we back
>> > that out please?
>> 
>> Ok, I will revert them.
>> 
>> >
>> >>         0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
>> >>         0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
>> >>         0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
>> >> @@ -125,12 +177,12 @@ static const u32 crctab32[] = {
>> >>         0x2d02ef8d
>> >>  };
>> >>
>> >> -static u32 partial_crc32_one(u8 c, u32 crc)
>> >> +static uint32_t partial_crc32_one(uint8_t c, uint32_t crc)
>> >>  {
>> >>         return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
>> >>  }
>> >>
>> >> -static u32 partial_crc32(const u8 *s, int len, u32 crc)
>> >> +static uint32_t partial_crc32(const uint8_t *s, int len, uint32_t
>> >> crc)
>> >>  {
>> >>         while (len--)
>> >>                 crc = partial_crc32_one(*s++, crc);
>> >> @@ -152,57 +204,106 @@ static void usage(void)
>> >>         die("Usage: build setup system zoffset.h image");
>> >>  }
>> >>
>> >> +static void *map_file(const char *path, size_t *psize)
>> >> +{
>> >> +       struct stat statbuf;
>> >> +       size_t size;
>> >> +       void *addr;
>> >> +       int fd;
>> >> +
>> >> +       fd = open(path, O_RDONLY);
>> >> +       if (fd < 0)
>> >> +               die("Unable to open `%s': %m", path);
>> >> +       if (fstat(fd, &statbuf))
>> >> +               die("Unable to stat `%s': %m", path);
>> >> +
>> >> +       size = statbuf.st_size;
>> >> +       /*
>> >> +        * Map one byte more, to allow adding null-terminator
>> >> +        * for text files.
>> >> +        */
>> >> +       addr = mmap(NULL, size + 1, PROT_READ | PROT_WRITE,
>> >> MAP_PRIVATE, fd, 0);
>> >> +       if (addr == MAP_FAILED)
>> >> +               die("Unable to mmap '%s': %m", path);
>> >> +
>> >> +       close(fd);
>> >> +
>> >> +       *psize = size;
>> >> +       return addr;
>> >> +}
>> >> +
>> >> +static void unmap_file(void *addr, size_t size)
>> >> +{
>> >> +       munmap(addr, size + 1);
>> >> +}
>> >> +
>> >> +static void *map_output_file(const char *path, size_t size)
>> >> +{
>> >> +       void *addr;
>> >> +       int fd;
>> >> +
>> >> +       fd = open(path, O_RDWR | O_CREAT, 0660);
>> >> +       if (fd < 0)
>> >> +               die("Unable to create `%s': %m", path);
>> >> +
>> >> +       if (ftruncate(fd, size))
>> >> +               die("Unable to resize `%s': %m", path);
>> >> +
>> >> +       addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED,
>> >> fd, 0);
>> >> +       if (addr == MAP_FAILED)
>> >> +               die("Unable to mmap '%s': %m", path);
>> >> +
>> >> +       return addr;
>> >> +}
>> >> +
>> >>  #ifdef CONFIG_EFI_STUB
>> >>
>> >> -static void update_pecoff_section_header_fields(char *section_name,
>> >> u32 vma, u32 size, u32 datasz, u32 offset)
>> >> +static void update_pecoff_section_header_fields(char *section_name,
>> >> uint32_t vma,
>> >> +                                               uint32_t size,
>> >> uint32_t datasz,
>> >> +                                               uint32_t offset)
>> >>  {
>> >>         unsigned int pe_header;
>> >>         unsigned short num_sections;
>> >> -       u8 *section;
>> >> +       struct section_header *section;
>> >>
>> >> -       pe_header = get_unaligned_le32(&buf[0x3c]);
>> >> -       num_sections = get_unaligned_le16(&buf[pe_header + 6]);
>> >> -
>> >> -#ifdef CONFIG_X86_32
>> >> -       section = &buf[pe_header + 0xa8];
>> >> -#else
>> >> -       section = &buf[pe_header + 0xb8];
>> >> -#endif
>> >> +       struct pe_hdr *hdr = get_pe_header(buf);
>> >> +       num_sections = get_unaligned_le16(&hdr->sections);
>> >> +       section = get_sections(buf);
>> >>
>> >>         while (num_sections > 0) {
>> >> -               if (strncmp((char*)section, section_name, 8) == 0) {
>> >> +               if (strncmp(section->name, section_name, 8) == 0) {
>> >>                         /* section header size field */
>> >> -                       put_unaligned_le32(size, section + 0x8);
>> >> +                       put_unaligned_le32(size,
>> >> &section->virtual_size);
>> >>
>> >>                         /* section header vma field */
>> >> -                       put_unaligned_le32(vma, section + 0xc);
>> >> +                       put_unaligned_le32(vma,
>> >> &section->virtual_address);
>> >>
>> >>                         /* section header 'size of initialised data'
>> >> field */
>> >> -                       put_unaligned_le32(datasz, section + 0x10);
>> >> +                       put_unaligned_le32(datasz,
>> >> &section->raw_data_size);
>> >>
>> >>                         /* section header 'file offset' field */
>> >> -                       put_unaligned_le32(offset, section + 0x14);
>> >> +                       put_unaligned_le32(offset,
>> >> &section->data_addr);
>> >>
>> >>                         break;
>> >>                 }
>> >> -               section += 0x28;
>> >> +               section++;
>> >>                 num_sections--;
>> >>         }
>> >>  }
>> >>
>> >> -static void update_pecoff_section_header(char *section_name, u32
>> >> offset, u32 size)
>> >> +static void update_pecoff_section_header(char *section_name, uint32_t
>> >> offset, uint32_t size)
>> >>  {
>> >>         update_pecoff_section_header_fields(section_name, offset,
>> >> size, size, offset);
>> >>  }
>> >>
>> >>  static void update_pecoff_setup_and_reloc(unsigned int size)
>> >>  {
>> >> -       u32 setup_offset = 0x200;
>> >> -       u32 reloc_offset = size - PECOFF_RELOC_RESERVE -
>> >> PECOFF_COMPAT_RESERVE;
>> >> +       uint32_t setup_offset = SECTOR_SIZE;
>> >> +       uint32_t reloc_offset = size - PECOFF_RELOC_RESERVE -
>> >> PECOFF_COMPAT_RESERVE;
>> >>  #ifdef CONFIG_EFI_MIXED
>> >> -       u32 compat_offset = reloc_offset + PECOFF_RELOC_RESERVE;
>> >> +       uint32_t compat_offset = reloc_offset + PECOFF_RELOC_RESERVE;
>> >>  #endif
>> >> -       u32 setup_size = reloc_offset - setup_offset;
>> >> +       uint32_t setup_size = reloc_offset - setup_offset;
>> >>
>> >>         update_pecoff_section_header(".setup", setup_offset,
>> >> setup_size);
>> >>         update_pecoff_section_header(".reloc", reloc_offset,
>> >> PECOFF_RELOC_RESERVE);
>> >> @@ -211,8 +312,8 @@ static void update_pecoff_setup_and_reloc(unsigned
>> >> int size)
>> >>          * Modify .reloc section contents with a single entry. The
>> >>          * relocation is applied to offset 10 of the relocation
>> >> section.
>> >>          */
>> >> -       put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]);
>> >> -       put_unaligned_le32(10, &buf[reloc_offset + 4]);
>> >> +       put_unaligned_le32(reloc_offset + RELOC_SECTION_SIZE,
>> >> &buf[reloc_offset]);
>> >> +       put_unaligned_le32(RELOC_SECTION_SIZE, &buf[reloc_offset +
>> >> 4]);
>> >>
>> >>  #ifdef CONFIG_EFI_MIXED
>> >>         update_pecoff_section_header(".compat", compat_offset,
>> >> PECOFF_COMPAT_RESERVE);
>> >> @@ -224,19 +325,17 @@ static void
>> >> update_pecoff_setup_and_reloc(unsigned int size)
>> >>          */
>> >>         buf[compat_offset] = 0x1;
>> >>         buf[compat_offset + 1] = 0x8;
>> >> -       put_unaligned_le16(0x14c, &buf[compat_offset + 2]);
>> >> +       put_unaligned_le16(IMAGE_FILE_MACHINE_I386, &buf[compat_offset
>> >> + 2]);
>> >>         put_unaligned_le32(efi32_pe_entry + size, &buf[compat_offset +
>> >> 4]);
>> >>  #endif
>> >>  }
>> >>
>> >> -static void update_pecoff_text(unsigned int text_start, unsigned int
>> >> file_sz,
>> >> +static unsigned int update_pecoff_sections(unsigned int text_start,
>> >> unsigned int text_sz,
>> >>                                unsigned int init_sz)
>> >>  {
>> >> -       unsigned int pe_header;
>> >> -       unsigned int text_sz = file_sz - text_start;
>> >> +       unsigned int file_sz = text_start + text_sz;
>> >>         unsigned int bss_sz = init_sz - file_sz;
>> >> -
>> >> -       pe_header = get_unaligned_le32(&buf[0x3c]);
>> >> +       pe_opt_hdr *hdr = get_pe_opt_header(buf);
>> >>
>> >>         /*
>> >>          * The PE/COFF loader may load the image at an address which
>> >> is
>> >> @@ -254,18 +353,20 @@ static void update_pecoff_text(unsigned int
>> >> text_start, unsigned int file_sz,
>> >>          * Size of code: Subtract the size of the first sector (512
>> >> bytes)
>> >>          * which includes the header.
>> >>          */
>> >> -       put_unaligned_le32(file_sz - 512 + bss_sz, &buf[pe_header +
>> >> 0x1c]);
>> >> +       put_unaligned_le32(file_sz - SECTOR_SIZE + bss_sz,
>> >> &hdr->text_size);
>> >>
>> >>         /* Size of image */
>> >> -       put_unaligned_le32(init_sz, &buf[pe_header + 0x50]);
>> >> +       put_unaligned_le32(init_sz, &hdr->image_size);
>> >>
>> >>         /*
>> >>          * Address of entry point for PE/COFF executable
>> >>          */
>> >> -       put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header +
>> >> 0x28]);
>> >> +       put_unaligned_le32(text_start + efi_pe_entry,
>> >> &hdr->entry_point);
>> >>
>> >>         update_pecoff_section_header_fields(".text", text_start,
>> >> text_sz + bss_sz,
>> >>                                             text_sz, text_start);
>> >> +
>> >> +       return text_start + file_sz;
>> >>  }
>> >>
>> >>  static int reserve_pecoff_reloc_section(int c)
>> >> @@ -275,7 +376,7 @@ static int reserve_pecoff_reloc_section(int c)
>> >>         return PECOFF_RELOC_RESERVE;
>> >>  }
>> >>
>> >> -static void efi_stub_defaults(void)
>> >> +static void efi_stub_update_defaults(void)
>> >>  {
>> >>         /* Defaults for old kernel */
>> >>  #ifdef CONFIG_X86_32
>> >> @@ -298,7 +399,7 @@ static void efi_stub_entry_update(void)
>> >>
>> >>  #ifdef CONFIG_EFI_MIXED
>> >>         if (efi32_stub_entry != addr)
>> >> -               die("32-bit and 64-bit EFI entry points do not
>> >> match\n");
>> >> +               die("32-bit and 64-bit EFI entry points do not
>> >> match");
>> >>  #endif
>> >>  #endif
>> >>         put_unaligned_le32(addr, &buf[0x264]);
>> >> @@ -310,7 +411,7 @@ static inline void
>> >> update_pecoff_setup_and_reloc(unsigned int size) {}
>> >>  static inline void update_pecoff_text(unsigned int text_start,
>> >>                                       unsigned int file_sz,
>> >>                                       unsigned int init_sz) {}
>> >> -static inline void efi_stub_defaults(void) {}
>> >> +static inline void efi_stub_update_defaults(void) {}
>> >>  static inline void efi_stub_entry_update(void) {}
>> >>
>> >>  static inline int reserve_pecoff_reloc_section(int c)
>> >> @@ -338,20 +439,15 @@ static int reserve_pecoff_compat_section(int c)
>> >>
>> >>  static void parse_zoffset(char *fname)
>> >>  {
>> >> -       FILE *file;
>> >> -       char *p;
>> >> -       int c;
>> >> +       size_t size;
>> >> +       char *data, *p;
>> >>
>> >> -       file = fopen(fname, "r");
>> >> -       if (!file)
>> >> -               die("Unable to open `%s': %m", fname);
>> >> -       c = fread(buf, 1, sizeof(buf) - 1, file);
>> >> -       if (ferror(file))
>> >> -               die("read-error on `zoffset.h'");
>> >> -       fclose(file);
>> >> -       buf[c] = 0;
>> >> +       data = map_file(fname, &size);
>> >>
>> >> -       p = (char *)buf;
>> >> +       /* We can do that, since we mapped one byte more */
>> >> +       data[size] = 0;
>> >> +
>> >> +       p = (char *)data;
>> >>
>> >>         while (p && *p) {
>> >>                 PARSE_ZOFS(p, efi32_stub_entry);
>> >> @@ -367,82 +463,99 @@ static void parse_zoffset(char *fname)
>> >>                 while (p && (*p == '\r' || *p == '\n'))
>> >>                         p++;
>> >>         }
>> >> +
>> >> +       unmap_file(data, size);
>> >>  }
>> >>
>> >> -int main(int argc, char ** argv)
>> >> +static unsigned int read_setup(char *path)
>> >>  {
>> >> -       unsigned int i, sz, setup_sectors, init_sz;
>> >> -       int c;
>> >> -       u32 sys_size;
>> >> -       struct stat sb;
>> >> -       FILE *file, *dest;
>> >> -       int fd;
>> >> -       void *kernel;
>> >> -       u32 crc = 0xffffffffUL;
>> >> -
>> >> -       efi_stub_defaults();
>> >> -
>> >> -       if (argc != 5)
>> >> -               usage();
>> >> -       parse_zoffset(argv[3]);
>> >> -
>> >> -       dest = fopen(argv[4], "w");
>> >> -       if (!dest)
>> >> -               die("Unable to write `%s': %m", argv[4]);
>> >> +       FILE *file;
>> >> +       unsigned int setup_size, file_size;
>> >>
>> >>         /* Copy the setup code */
>> >> -       file = fopen(argv[1], "r");
>> >> +       file = fopen(path, "r");
>> >>         if (!file)
>> >> -               die("Unable to open `%s': %m", argv[1]);
>> >> -       c = fread(buf, 1, sizeof(buf), file);
>> >> +               die("Unable to open `%s': %m", path);
>> >> +
>> >> +       file_size = fread(buf, 1, sizeof(buf), file);
>> >>         if (ferror(file))
>> >>                 die("read-error on `setup'");
>> >> -       if (c < 1024)
>> >> +
>> >> +       if (file_size < 2 * SECTOR_SIZE)
>> >>                 die("The setup must be at least 1024 bytes");
>> >> -       if (get_unaligned_le16(&buf[510]) != 0xAA55)
>> >> +
>> >> +       if (get_unaligned_le16(&buf[SECTOR_SIZE - 2]) != 0xAA55)
>> >>                 die("Boot block hasn't got boot flag (0xAA55)");
>> >> +
>> >>         fclose(file);
>> >>
>> >> -       c += reserve_pecoff_compat_section(c);
>> >> -       c += reserve_pecoff_reloc_section(c);
>> >> +       /* Reserve space for PE sections */
>> >> +       file_size += reserve_pecoff_compat_section(file_size);
>> >> +       file_size += reserve_pecoff_reloc_section(file_size);
>> >>
>> >>         /* Pad unused space with zeros */
>> >> -       setup_sectors = (c + 511) / 512;
>> >> -       if (setup_sectors < SETUP_SECT_MIN)
>> >> -               setup_sectors = SETUP_SECT_MIN;
>> >> -       i = setup_sectors*512;
>> >> -       memset(buf+c, 0, i-c);
>> >>
>> >> -       update_pecoff_setup_and_reloc(i);
>> >> +       setup_size = round_up(file_size, SECTOR_SIZE);
>> >> +
>> >> +       if (setup_size < SETUP_SECT_MIN * SECTOR_SIZE)
>> >> +               setup_size = SETUP_SECT_MIN * SECTOR_SIZE;
>> >> +
>> >> +       /*
>> >> +        * Global buffer is already initialised
>> >> +        * to 0, but just in case, zero out padding.
>> >> +        */
>> >> +
>> >> +       memset(buf + file_size, 0, setup_size - file_size);
>> >> +
>> >> +       return setup_size;
>> >> +}
>> >> +
>> >> +int main(int argc, char **argv)
>> >> +{
>> >> +       size_t kern_file_size;
>> >> +       unsigned int setup_size;
>> >> +       unsigned int setup_sectors;
>> >> +       unsigned int init_size;
>> >> +       unsigned int total_size;
>> >> +       unsigned int kern_size;
>> >> +       void *kernel;
>> >> +       uint32_t crc = 0xffffffffUL;
>> >> +       uint8_t *output;
>> >> +
>> >> +       if (argc != 5)
>> >> +               usage();
>> >> +
>> >> +       efi_stub_update_defaults();
>> >> +       parse_zoffset(argv[3]);
>> >> +
>> >> +       setup_size = read_setup(argv[1]);
>> >> +
>> >> +       setup_sectors = setup_size/SECTOR_SIZE;
>> >>
>> >>         /* Set the default root device */
>> >>         put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]);
>> >>
>> >> -       /* Open and stat the kernel file */
>> >> -       fd = open(argv[2], O_RDONLY);
>> >> -       if (fd < 0)
>> >> -               die("Unable to open `%s': %m", argv[2]);
>> >> -       if (fstat(fd, &sb))
>> >> -               die("Unable to stat `%s': %m", argv[2]);
>> >> -       sz = sb.st_size;
>> >> -       kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
>> >> -       if (kernel == MAP_FAILED)
>> >> -               die("Unable to mmap '%s': %m", argv[2]);
>> >> -       /* Number of 16-byte paragraphs, including space for a 4-byte
>> >> CRC */
>> >> -       sys_size = (sz + 15 + 4) / 16;
>> >> +       /* Map kernel file to memory */
>> >> +       kernel = map_file(argv[2], &kern_file_size);
>> >> +
>> >>  #ifdef CONFIG_EFI_STUB
>> >> -       /*
>> >> -        * COFF requires minimum 32-byte alignment of sections, and
>> >> -        * adding a signature is problematic without that alignment.
>> >> -        */
>> >> -       sys_size = (sys_size + 1) & ~1;
>> >> +       /* PE specification require 512-byte minimum section file
>> >> alignment */
>> >> +       kern_size = round_up(kern_file_size + 4, SECTOR_SIZE);
>> >> +       update_pecoff_setup_and_reloc(setup_size);
>> >> +#else
>> >> +       /* Number of 16-byte paragraphs, including space for a 4-byte
>> >> CRC */
>> >> +       kern_size = round_up(kern_file_size + 4, PARAGRAPH_SIZE);
>> >>  #endif
>> >>
>> >>         /* Patch the setup code with the appropriate size parameters
>> >> */
>> >> -       buf[0x1f1] = setup_sectors-1;
>> >> -       put_unaligned_le32(sys_size, &buf[0x1f4]);
>> >> +       buf[0x1f1] = setup_sectors - 1;
>> >> +       put_unaligned_le32(kern_size/PARAGRAPH_SIZE, &buf[0x1f4]);
>> >> +
>> >> +       /* Update kernel_info offset. */
>> >> +       put_unaligned_le32(kernel_info, &buf[0x268]);
>> >> +
>> >> +       init_size = get_unaligned_le32(&buf[0x260]);
>> >>
>> >> -       init_sz = get_unaligned_le32(&buf[0x260]);
>> >>  #ifdef CONFIG_EFI_STUB
>> >>         /*
>> >>          * The decompression buffer will start at ImageBase. When
>> >> relocating
>> >> @@ -458,45 +571,35 @@ int main(int argc, char ** argv)
>> >>          * For future-proofing, increase init_sz if necessary.
>> >>          */
>> >>
>> >> -       if (init_sz - _end < i + _ehead) {
>> >> -               init_sz = (i + _ehead + _end + 4095) & ~4095;
>> >> -               put_unaligned_le32(init_sz, &buf[0x260]);
>> >> +       if (init_size - _end < setup_size + _ehead) {
>> >> +               init_size = round_up(setup_size + _ehead + _end,
>> >> SECTION_ALIGNMENT);
>> >> +               put_unaligned_le32(init_size, &buf[0x260]);
>> >>         }
>> >> -#endif
>> >> -       update_pecoff_text(setup_sectors * 512, i + (sys_size * 16),
>> >> init_sz);
>> >>
>> >> -       efi_stub_entry_update();
>> >> -
>> >> -       /* Update kernel_info offset. */
>> >> -       put_unaligned_le32(kernel_info, &buf[0x268]);
>> >> +       total_size = update_pecoff_sections(setup_size, kern_size,
>> >> init_size);
>> >>
>> >> -       crc = partial_crc32(buf, i, crc);
>> >> -       if (fwrite(buf, 1, i, dest) != i)
>> >> -               die("Writing setup failed");
>> >> +       efi_stub_entry_update();
>> >> +#else
>> >> +       (void)init_size;
>> >> +       total_size = setup_size + kern_size;
>> >> +#endif
>> >>
>> >> -       /* Copy the kernel code */
>> >> -       crc = partial_crc32(kernel, sz, crc);
>> >> -       if (fwrite(kernel, 1, sz, dest) != sz)
>> >> -               die("Writing kernel failed");
>> >> +       output = map_output_file(argv[4], total_size);
>> >>
>> >> -       /* Add padding leaving 4 bytes for the checksum */
>> >> -       while (sz++ < (sys_size*16) - 4) {
>> >> -               crc = partial_crc32_one('\0', crc);
>> >> -               if (fwrite("\0", 1, 1, dest) != 1)
>> >> -                       die("Writing padding failed");
>> >> -       }
>> >> +       memcpy(output, buf, setup_size);
>> >> +       memcpy(output + setup_size, kernel, kern_file_size);
>> >> +       memset(output + setup_size + kern_file_size, 0, kern_size -
>> >> kern_file_size);
>> >>
>> >> -       /* Write the CRC */
>> >> -       put_unaligned_le32(crc, buf);
>> >> -       if (fwrite(buf, 1, 4, dest) != 4)
>> >> -               die("Writing CRC failed");
>> >> +       /* Calculate and write kernel checksum. */
>> >> +       crc = partial_crc32(output, total_size - 4, crc);
>> >> +       put_unaligned_le32(crc, &output[total_size - 4]);
>> >>
>> >> -       /* Catch any delayed write failures */
>> >> -       if (fclose(dest))
>> >> -               die("Writing image failed");
>> >> +       /* Catch any delayed write failures. */
>> >> +       if (munmap(output, total_size) < 0)
>> >> +               die("Writing kernel failed");
>> >>
>> >> -       close(fd);
>> >> +       unmap_file(kernel, kern_file_size);
>> >>
>> >> -       /* Everything is OK */
>> >> +       /* Everything is OK. */
>> >>         return 0;
>> >>  }
>> >> --
>> >> 2.37.4
>> >>

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