linux-stable.git/scripts, branch linux-6.3.y

kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb

2023-07-11T17:39:51+00:00

[ Upstream commit 1240dabe8d58b4eff09e7edf1560da0360f997aa ]

When CONFIG_MODULES is disabled for ARCH=um, 'make (bin)deb-pkg' fails
with an error like follows:

  cp: cannot create regular file 'debian/linux-image/usr/lib/uml/modules/6.4.0-rc2+/System.map': No such file or directory

Remove the CONFIG_MODULES check completely so ${pdir}/usr/lib/uml/modules
will always be created and modules.builtin.(modinfo) will be installed
under it for ARCH=um.

Fixes: b611daae5efc ("kbuild: deb-pkg: split image and debug objects staging out into functions")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

kbuild: builddeb: always make modules_install, to install modules.builtin*

2023-07-11T17:39:51+00:00

[ Upstream commit 4243afdb932677a03770753be8c54b3190a512e8 ]

Even for a non-modular kernel, the kernel builds modules.builtin and
modules.builtin.modinfo, with information about the built-in modules.
Tools such as initramfs-tools need these files to build a working
initramfs on some systems, such as those requiring firmware.

Now that `make modules_install` works even in non-modular kernels and
installs these files, unconditionally invoke it when building a Debian
package.

Signed-off-by: Josh Triplett 
Reviewed-by: Nicolas Schier 
Signed-off-by: Masahiro Yamada 
Stable-dep-of: 1240dabe8d58 ("kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb")
Signed-off-by: Sasha Levin

kbuild: Disable GCOV for *.mod.o

2023-07-11T17:39:50+00:00

[ Upstream commit 25a21fbb934a0d989e1858f83c2ddf4cfb2ebe30 ]

With GCOV_PROFILE_ALL, Clang injects __llvm_gcov_* functions to each
object file, including the *.mod.o. As we filter out CC_FLAGS_CFI
for *.mod.o, the compiler won't generate type hashes for the
injected functions, and therefore indirectly calling them during
module loading trips indirect call checking.

Enabling CFI for *.mod.o isn't sufficient to fix this issue after
commit 0c3e806ec0f9 ("x86/cfi: Add boot time hash randomization"),
as *.mod.o aren't processed by objtool, which means any hashes
emitted there won't be randomized. Therefore, in addition to
disabling CFI for *.mod.o, also disable GCOV, as the object files
don't otherwise contain any executable code.

Fixes: cf68fffb66d6 ("add support for Clang CFI")
Reported-by: Joe Fradley 
Signed-off-by: Sami Tolvanen 
Acked-by: Peter Zijlstra (Intel) 
Reviewed-by: Kees Cook 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

kbuild: Fix CFI failures with GCOV

2023-07-11T17:39:50+00:00

[ Upstream commit ddf56288eebd1fe82c46fc9f693b5b18045cddb6 ]

With GCOV_PROFILE_ALL, Clang injects __llvm_gcov_* functions to
each object file, and the functions are indirectly called during
boot. However, when code is injected to object files that are not
part of vmlinux.o, it's also not processed by objtool, which breaks
CFI hash randomization as the hashes in these files won't be
included in the .cfi_sites section and thus won't be randomized.

Similarly to commit 42633ed852de ("kbuild: Fix CFI hash
randomization with KASAN"), disable GCOV for .vmlinux.export.o and
init/version-timestamp.o to avoid emitting unnecessary functions to
object files that don't otherwise have executable code.

Fixes: 0c3e806ec0f9 ("x86/cfi: Add boot time hash randomization")
Reported-by: Joe Fradley 
Signed-off-by: Sami Tolvanen 
Acked-by: Peter Zijlstra (Intel) 
Reviewed-by: Kees Cook 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

modpost: fix off by one in is_executable_section()

2023-07-11T17:39:49+00:00

[ Upstream commit 3a3f1e573a105328a2cca45a7cfbebabbf5e3192 ]

The > comparison should be >= to prevent an out of bounds array
access.

Fixes: 52dc0595d540 ("modpost: handle relocations mismatch in __ex_table.")
Signed-off-by: Dan Carpenter 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

modpost: fix section mismatch message for R_ARM_{PC24,CALL,JUMP24}

2023-07-11T17:39:49+00:00

[ Upstream commit 56a24b8ce6a7f9c4a21b2276a8644f6f3d8fc14d ]

addend_arm_rel() processes R_ARM_PC24, R_ARM_CALL, R_ARM_JUMP24 in a
wrong way.

Here, test code.

[test code for R_ARM_JUMP24]

  .section .init.text,"ax"
  bar:
          bx      lr

  .section .text,"ax"
  .globl foo
  foo:
          b       bar

[test code for R_ARM_CALL]

  .section .init.text,"ax"
  bar:
          bx      lr

  .section .text,"ax"
  .globl foo
  foo:
          push    {lr}
          bl      bar
          pop     {pc}

If you compile it with ARM multi_v7_defconfig, modpost will show the
symbol name, (unknown).

  WARNING: modpost: vmlinux.o: section mismatch in reference: foo (section: .text) -> (unknown) (section: .init.text)

(You need to use GNU linker instead of LLD to reproduce it.)

Fix the code to make modpost show the correct symbol name.

I imported (with adjustment) sign_extend32() from include/linux/bitops.h.

The '+8' is the compensation for pc-relative instruction. It is
documented in "ELF for the Arm Architecture" [1].

  "If the relocation is pc-relative then compensation for the PC bias
  (the PC value is 8 bytes ahead of the executing instruction in Arm
  state and 4 bytes in Thumb state) must be encoded in the relocation
  by the object producer."

[1]: https://github.com/ARM-software/abi-aa/blob/main/aaelf32/aaelf32.rst

Fixes: 56a974fa2d59 ("kbuild: make better section mismatch reports on arm")
Fixes: 6e2e340b59d2 ("ARM: 7324/1: modpost: Fix section warnings for ARM for many compilers")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

modpost: fix section mismatch message for R_ARM_ABS32

2023-07-11T17:39:49+00:00

[ Upstream commit b7c63520f6703a25eebb4f8138fed764fcae1c6f ]

addend_arm_rel() processes R_ARM_ABS32 in a wrong way.

Here, test code.

  [test code 1]

    #include 

    int __initdata foo;
    int get_foo(void) { return foo; }

If you compile it with ARM versatile_defconfig, modpost will show the
symbol name, (unknown).

  WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> (unknown) (section: .init.data)

(You need to use GNU linker instead of LLD to reproduce it.)

If you compile it for other architectures, modpost will show the correct
symbol name.

  WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)

For R_ARM_ABS32, addend_arm_rel() sets r->r_addend to a wrong value.

I just mimicked the code in arch/arm/kernel/module.c.

However, there is more difficulty for ARM.

Here, test code.

  [test code 2]

    #include 

    int __initdata foo;
    int get_foo(void) { return foo; }

    int __initdata bar;
    int get_bar(void) { return bar; }

With this commit applied, modpost will show the following messages
for ARM versatile_defconfig:

  WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)
  WARNING: modpost: vmlinux.o: section mismatch in reference: get_bar (section: .text) -> foo (section: .init.data)

The reference from 'get_bar' to 'foo' seems wrong.

I have no solution for this because it is true in assembly level.

In the following output, relocation at 0x1c is no longer associated
with 'bar'. The two relocation entries point to the same symbol, and
the offset to 'bar' is encoded in the instruction 'r0, [r3, #4]'.

  Disassembly of section .text:

  00000000 :
     0: e59f3004          ldr     r3, [pc, #4]   @ c 
     4: e5930000          ldr     r0, [r3]
     8: e12fff1e          bx      lr
     c: 00000000          .word   0x00000000

  00000010 :
    10: e59f3004          ldr     r3, [pc, #4]   @ 1c 
    14: e5930004          ldr     r0, [r3, #4]
    18: e12fff1e          bx      lr
    1c: 00000000          .word   0x00000000

  Relocation section '.rel.text' at offset 0x244 contains 2 entries:
   Offset     Info    Type            Sym.Value  Sym. Name
  0000000c  00000c02 R_ARM_ABS32       00000000   .init.data
  0000001c  00000c02 R_ARM_ABS32       00000000   .init.data

When find_elf_symbol() gets into a situation where relsym->st_name is
zero, there is no guarantee to get the symbol name as written in C.

I am keeping the current logic because it is useful in many architectures,
but the symbol name is not always correct depending on the optimization.
I left some comments in find_tosym().

Fixes: 56a974fa2d59 ("kbuild: make better section mismatch reports on arm")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

modpost: remove broken calculation of exception_table_entry size

2023-07-11T17:39:49+00:00

[ Upstream commit d0acc76a49aa917c1a455d11d32d34a01e8b2835 ]

find_extable_entry_size() is completely broken. It has awesome comments
about how to calculate sizeof(struct exception_table_entry).

It was based on these assumptions:

  - struct exception_table_entry has two fields
  - both of the fields have the same size

Then, we came up with this equation:

  (offset of the second field) * 2 == (size of struct)

It was true for all architectures when commit 52dc0595d540 ("modpost:
handle relocations mismatch in __ex_table.") was applied.

Our mathematics broke when commit 548acf19234d ("x86/mm: Expand the
exception table logic to allow new handling options") introduced the
third field.

Now, the definition of exception_table_entry is highly arch-dependent.

For x86, sizeof(struct exception_table_entry) is apparently 12, but
find_extable_entry_size() sets extable_entry_size to 8.

I could fix it, but I do not see much value in this code.

extable_entry_size is used just for selecting a slightly different
error message.

If the first field ("insn") references to a non-executable section,

    The relocation at %s+0x%lx references
    section "%s" which is not executable, IOW
    it is not possible for the kernel to fault
    at that address.  Something is seriously wrong
    and should be fixed.

If the second field ("fixup") references to a non-executable section,

    The relocation at %s+0x%lx references
    section "%s" which is not executable, IOW
    the kernel will fault if it ever tries to
    jump to it.  Something is seriously wrong
    and should be fixed.

Merge the two error messages rather than adding even more complexity.

Change fatal() to error() to make it continue running and catch more
possible errors.

Fixes: 548acf19234d ("x86/mm: Expand the exception table logic to allow new handling options")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

scripts/tags.sh: Resolve gtags empty index generation

2023-07-05T17:29:23+00:00

commit e1b37563caffc410bb4b55f153ccb14dede66815 upstream.

gtags considers any file outside of its current working directory
"outside the source tree" and refuses to index it. For O= kernel builds,
or when "make" is invoked from a directory other then the kernel source
tree, gtags ignores the entire kernel source and generates an empty
index.

Force-set gtags current working directory to the kernel source tree.

Due to commit 9da0763bdd82 ("kbuild: Use relative path when building in
a subdir of the source tree"), if the kernel build is done in a
sub-directory of the kernel source tree, the kernel Makefile will set
the kernel's $srctree to ".." for shorter compile-time and run-time
warnings. Consequently, the list of files to be indexed will be in the
"../*" form, rendering all such paths invalid once gtags switches to the
kernel source tree as its current working directory.

If gtags indexing is requested and the build directory is not the kernel
source tree, index all files in absolute-path form.

Note, indexing in absolute-path form will not affect the generated
index, as paths in gtags indices are always relative to the gtags "root
directory" anyway (as evidenced by "gtags --dump").

Signed-off-by: Ahmed S. Darwish 
Cc: 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Greg Kroah-Hartman

x86/unwind/orc: Add ELF section with ORC version identifier

2023-06-28T09:14:24+00:00

[ Upstream commit b9f174c811e3ae4ae8959dc57e6adb9990e913f4 ]

Commits ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC
metadata") and fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in
two") changed the ORC format. Although ORC is internal to the kernel,
it's the only way for external tools to get reliable kernel stack traces
on x86-64. In particular, the drgn debugger [1] uses ORC for stack
unwinding, and these format changes broke it [2]. As the drgn
maintainer, I don't care how often or how much the kernel changes the
ORC format as long as I have a way to detect the change.

It suffices to store a version identifier in the vmlinux and kernel
module ELF files (to use when parsing ORC sections from ELF), and in
kernel memory (to use when parsing ORC from a core dump+symbol table).
Rather than hard-coding a version number that needs to be manually
bumped, Peterz suggested hashing the definitions from orc_types.h. If
there is a format change that isn't caught by this, the hashing script
can be updated.

This patch adds an .orc_header allocated ELF section containing the
20-byte hash to vmlinux and kernel modules, along with the corresponding
__start_orc_header and __stop_orc_header symbols in vmlinux.

1: https://github.com/osandov/drgn
2: https://github.com/osandov/drgn/issues/303

Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata")
Fixes: fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two")
Signed-off-by: Omar Sandoval 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Josh Poimboeuf 
Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com
Signed-off-by: Sasha Levin