Add the required typedefs etc for using con_in's simple text input
protocol, and for using the boottime event services.

Also add the prototype for the "stall" boot service.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-19-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Use the efi_printk function in efi_info/efi_err, and add efi_debug. This
allows formatted output at different log levels.

Add the notion of a loglevel instead of just quiet/not-quiet, and
parse the efi=debug kernel parameter in addition to quiet.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200520170223.GA3333632@rani.riverdale.lan/Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

Implement vsnprintf instead of vsprintf to avoid the possibility of a
buffer overflow.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-17-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

If we get an invalid conversion specifier, bail out instead of trying to
fix it up. The format string likely has a typo or assumed we support
something that we don't, in either case the remaining arguments won't
match up with the remaining format string.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-16-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Consolidate the actual output of the formatted text into one place.

Fix a couple of edge cases:
1. If 0 is printed with a precision of 0, the printf specification says
   that nothing should be output, with one exception (2b).
2. The specification for octal alternate format (%#o) adds the leading
   zero not as a prefix as the 0x for hexadecimal is, but by increasing
   the precision if necessary to add the zero. This means that
   a. %#.2o turns 8 into "010", but 1 into "01" rather than "001".
   b. %#.o prints 0 as "0" rather than "", unlike the situation for
      decimal, hexadecimal and regular octal format, which all output an
      empty string.

Reduce the space allocated for printing a number to the maximum actually
required (22 bytes for a 64-bit number in octal), instead of the 66
bytes previously allocated.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-15-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Print "(null)" for 's' if the input is a NULL pointer.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-14-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Factor out the code to get the correct type of numeric argument into a
helper function.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-13-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Factor out the width/precision parsing into a helper function.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-12-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Treat 'p' as a hexadecimal integer with precision equal to the number of
digits in void *.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-11-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

A negative precision should be ignored completely, and the presence of a
valid precision should turn off the 0 flag.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-10-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Move flags parsing code out into a helper function.

The '%%' case can be handled up front: it is not allowed to have flags,
width etc.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-9-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Support 'll' qualifier for long long by copying the decimal printing
code from lib/vsprintf.c. For simplicity, the 32-bit code is used on
64-bit architectures as well.

Support 'hh' qualifier for signed/unsigned char type integers.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-8-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

%n is unused and deprecated.

The L qualifer is parsed but not actually implemented.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-7-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Reclaim the bloat from the addition of printf by optimizing the stub for
size. With gcc 9, the text size of the stub is:

ARCH    before  +printf    -Os
arm      35197    37889  34638
arm64    34883    38159  34479
i386     18571    21657  17025
x86_64   25677    29328  22144
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-6-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Copy vsprintf from arch/x86/boot/printf.c to get a simple printf
implementation.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-5-nivedita@alum.mit.edu
[ardb: add some missing braces in if...else clauses]
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

Use a buffer to convert the string to UTF-16. This will reduce the
number of firmware calls required to print the string from one per
character to one per string in most cases.

Cast the input char to unsigned char before converting to efi_char16_t
to avoid sign-extension in case there are any non-ASCII characters in
the input.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-4-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

These functions do not support formatting, unlike printk. Rename them to
puts to make that clear.

Move the implementations of these two functions next to each other.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-3-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Add #include directives for include files that efistub.h depends on,
instead of relying on them having been included by the C source files
prior to efistub.h.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-2-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Fix a couple typos in comments.
Signed-off-by: NJoe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/ec53e67b3ac928922807db3cb1585e911971dadc.1588273612.git.joe@perches.comSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

To help the compiler figure out that efi_printk() will not modify
the string it is given, make the input argument type const char*.

While at it, simplify the implementation as well.
Suggested-by: NJoe Perches <joe@perches.com>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

When building the x86 EFI stub with Clang, the libstub Makefile rules
that manipulate the ELF object files may throw an error like:

    STUBCPY drivers/firmware/efi/libstub/efi-stub-helper.stub.o
  strip: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10
  objcopy: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10

This is the result of a LLVM feature [0] where symbol references are
stored in a LLVM specific .llvm_addrsig section in a non-transparent way,
causing generic ELF tools such as strip or objcopy to choke on them.

So force the compiler not to emit these sections, by passing the
appropriate command line option.

[0] https://sourceware.org/bugzilla/show_bug.cgi?id=23817

Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Suggested-by: NFangrui Song <maskray@google.com>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

Commit

  22090f84 ("efi/libstub: unify EFI call wrappers for non-x86")

refactored the macros that are used to provide wrappers for mixed-mode
calls on x86, allowing us to boot a 64-bit kernel on 32-bit firmware.

Unfortunately, this broke mixed mode boot due to the fact that
efi_is_native() is not a macro on x86.

All of these macros should go together, so rather than testing each one
to see if it is defined, condition the generic macro definitions on a
new ARCH_HAS_EFISTUB_WRAPPERS, and remove the wrapper definitions on x86
as well if CONFIG_EFI_MIXED is not enabled.

Fixes: 22090f84 ("efi/libstub: unify EFI call wrappers for non-x86")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200504150248.62482-1-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

efi_parse_options can fail if it is unable to allocate space for a copy
of the command line. Check the return value to make sure it succeeded.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-12-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Add support for the x86 CMDLINE_BOOL and CMDLINE_OVERRIDE configuration
options.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-11-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Factor out the initrd loading into a common function that can be called
both from the generic efi-stub.c and the x86-specific x86-stub.c.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-10-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Consolidate the initrd loading in efi_main.

The command line options now need to be parsed only once.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-9-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Use efi_err if we ignore a command-line dtb= argument, so that it shows
up even on a quiet boot.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-8-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Use efi_err instead of bare efi_printk for error messages.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-7-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Use efi_err instead of bare efi_printk for error messages.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-6-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Use efi_err instead of bare efi_printk for error messages.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-5-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Rename pr_efi to efi_info and pr_efi_err to efi_err to make it more
obvious that they are part of the EFI stub and not generic printk infra.
Suggested-by: NJoe Perches <joe@perches.com>
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-4-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

In several places 64-bit values need to be split up into two 32-bit
fields, in order to be backward-compatible with the old 32-bit ABIs.

Instead of open-coding this, add a helper function to set a 64-bit value
as two 32-bit fields.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-3-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

struct boot_params is only 4096 bytes, not 16384. Fix this by using
sizeof(struct boot_params) instead of hardcoding the incorrect value.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-2-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

We no longer need to take special care when using global variables
in the EFI stub, so switch to a simple symbol reference for efi_is64.
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

The practice of using __pure getter functions to access global
variables in the EFI stub dates back to the time when we had to
carefully prevent GOT entries from being emitted, because we
could not rely on the toolchain to do this for us.

Today, we use the hidden visibility pragma for all EFI stub source
files, which now all live in the same subdirectory, and we apply a
sanity check on the objects, so we can get rid of these getter
functions and simply refer to global data objects directly.

So switch over the remaining boolean variables carrying options set
on the kernel command line.
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

The practice of using __pure getter functions to access global
variables in the EFI stub dates back to the time when we had to
carefully prevent GOT entries from being emitted, because we
could not rely on the toolchain to do this for us.

Today, we use the hidden visibility pragma for all EFI stub source
files, which now all live in the same subdirectory, and we apply a
sanity check on the objects, so we can get rid of these getter
functions and simply refer to global data objects directly.

Start with efi_system_table(), and convert it into a global variable.
While at it, make it a pointer-to-const, because we can.
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>

Now that both arm and x86 are using the linker script to place the EFI
stub's global variables in the correct section, remove __efistub_global.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: NArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200416151227.3360778-4-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
into .data in the linker script for the compressed kernel.

Add relocation checking for x86 as well to catch non-PC-relative
relocations that require runtime processing, since the EFI stub does not
do any runtime relocation processing.

This will catch, for example, data relocations created by static
initializers of pointers.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200416151227.3360778-3-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
into .data in the linker script for the compressed kernel.
Signed-off-by: NArvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: NArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200416151227.3360778-2-nivedita@alum.mit.eduSigned-off-by: NArd Biesheuvel <ardb@kernel.org>

Move efi_relocate_kernel() into a separate source file, so that it
only gets pulled into builds for architectures that use it. Since
efi_relocate_kernel() is the only user of efi_low_alloc(), let's
move that over as well.
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>