Sysctl handlers are not supposed to modify the ctl_table passed to them.
Adapt the logic to work with a temporary variable, similar to how it is
done in other parts of the kernel.

This is also a prerequisite to enforce the immutability of the argument
through the callbacks.
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Tycho Andersen <tycho@tycho.pizza>
Link: https://lore.kernel.org/r/20240503-sysctl-const-stackleak-v1-1-603fecb19170@weissschuh.netSigned-off-by: Kees Cook <keescook@chromium.org>

Several other "dup"-style interfaces could use the __realloc_size()
attribute. (As a reminder to myself and others: "realloc" is used here
instead of "alloc" because the "alloc_size" attribute implies that the
memory contents are uninitialized. Since we're copying contents into the
resulting allocation, it must use "realloc_size" to avoid confusing the
compiler's optimization passes.)

Add KUnit test coverage where possible. (KUnit still does not have the
ability to manipulate userspace memory.)
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240502145218.it.729-kees@kernel.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The __alloc_size annotation for kmemdup() was getting disabled under
KUnit testing because the replaced fortify_panic macro implementation
was using "return NULL" as a way to survive the sanity checking. But
having the chance to return NULL invalidated __alloc_size, so kmemdup
was not passing the __builtin_dynamic_object_size() tests any more:

[23:26:18] [PASSED] fortify_test_alloc_size_kmalloc_const
[23:26:19]     # fortify_test_alloc_size_kmalloc_dynamic: EXPECTATION FAILED at lib/fortify_kunit.c:265
[23:26:19]     Expected __builtin_dynamic_object_size(p, 1) == expected, but
[23:26:19]         __builtin_dynamic_object_size(p, 1) == -1 (0xffffffffffffffff)
[23:26:19]         expected == 11 (0xb)
[23:26:19] __alloc_size() not working with __bdos on kmemdup("hello there", len, gfp)
[23:26:19] [FAILED] fortify_test_alloc_size_kmalloc_dynamic

Normal builds were not affected: __alloc_size continued to work there.

Use a zero-sized allocation instead, which allows __alloc_size to
behave.

Fixes: 4ce615e7 ("fortify: Provide KUnit counters for failure testing")
Fixes: fa4a3f86 ("fortify: Add KUnit tests for runtime overflows")
Link: https://lore.kernel.org/r/20240501232937.work.532-kees@kernel.orgSigned-off-by: Kees Cook <keescook@chromium.org>

Add some stuff that got missed along the way:

- CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y so SCS vs PAC is hardware
  selectable.

- CONFIG_X86_KERNEL_IBT=y while a default, just be sure.

- CONFIG_CFI_CLANG=y globally.

- CONFIG_PAGE_TABLE_CHECK=y for userspace mapping sanity.
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240501193709.make.982-kees@kernel.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The EXEC_RODATA test plays a lot of tricks to live in the .rodata section,
and once again ran into objtool's (completely reasonable) assumptions
that executable code should live in an executable section. However, this
manifested only under CONFIG_CFI_CLANG=y, as one of the .cfi_sites was
pointing into the .rodata section.

Since we're testing non-CFI execution properties in perms.c (and
rodata.c), we can disable CFI for the involved functions, and remove the
CFI arguments from rodata.c entirely.
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202308301532.d7acf63e-oliver.sang@intel.com
Fixes: 6342a20e ("objtool: Add elf_create_section_pair()")
Link: https://lore.kernel.org/r/20240430234953.work.760-kees@kernel.orgSigned-off-by: Kees Cook <keescook@chromium.org>

Add fortify tests for memcpy() and memmove(). This can use a similar
method to the fortify_panic() replacement, only we can do it for what
was the WARN_ONCE(), which can be redefined.

Since this is primarily testing the fortify behaviors of the memcpy()
and memmove() defenses, the tests for memcpy() and memmove() are
identical.

Link: https://lore.kernel.org/r/20240429194342.2421639-3-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

When running KUnit fortify tests, we're already doing precise tracking
of which warnings are getting hit. Don't fill the logs with WARNs unless
we've been explicitly built with DEBUG enabled.

Link: https://lore.kernel.org/r/20240429194342.2421639-2-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The recommended conventions for KUnit tests is ${module}_test_${what}.
Adjust the fortify tests to match.

Link: https://lore.kernel.org/r/20240429194342.2421639-1-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

data_page wants to be NUL-terminated and NUL-padded, use strscpy_pad to
provide both of these. data_page no longer awkwardly relies on
init_mount to perform its NUL-termination, although that sanity check is
left unchanged.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc:  <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240402-strncpy-init-do_mounts-c-v1-1-e16d7bc20974@google.comSigned-off-by: Kees Cook <keescook@chromium.org>

The kv*() family of tests were accidentally freeing with vfree() instead
of kvfree(). Use kvfree() instead.

Fixes: 9124a264 ("kunit/fortify: Validate __alloc_size attribute results")
Link: https://lore.kernel.org/r/20240425230619.work.299-kees@kernel.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The prior strlcpy() replacement of strncpy() here (which was
later replaced with strscpy()) expected pinfo->model_num (and
pinfo->model_description) to be NUL-terminated, but it is possible
it was not, as the code pattern here shows vha->hw->model_number (and
vha->hw->model_desc) being exactly 1 character larger, and the replaced
strncpy() was copying only up to the size of the source character
array. Replace this with memtostr(), which is the unambiguous way to
convert a maybe not-NUL-terminated character array into a NUL-terminated
string.

Fixes: 527e9b70 ("scsi: qla2xxx: Use memcpy() and strlcpy() instead of strcpy() and strncpy()")
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240410023155.2100422-5-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The prior use of strscpy() here expected the manufacture_reply strings to
be NUL-terminated, but it is possible they are not, as the code pattern
here shows, e.g., edev->vendor_id being exactly 1 character larger than
manufacture_reply->vendor_id, and the strscpy() was copying only up to
the size of the source character array. Replace this with memtostr(),
which is the unambiguous way to convert a maybe not-NUL-terminated
character array into a NUL-terminated string.

Fixes: 2bd37e28 ("scsi: mpi3mr: Add framework to issue MPT transport cmds")
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240410023155.2100422-4-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The prior strscpy() replacement of strncpy() here expected the
manufacture_reply strings to be NUL-terminated, but it is possible
they are not, as the code pattern here shows, e.g., edev->vendor_id
being exactly 1 character larger than manufacture_reply->vendor_id,
and the replaced strncpy() was copying only up to the size of the
source character array. Replace this with memtostr(), which is the
unambiguous way to convert a maybe not-NUL-terminated character array
into a NUL-terminated string.
Reported-by: Charles Bertsch <cbertsch@cox.net>
Closes: https://lore.kernel.org/all/5445ba0f-3e27-4d43-a9ba-0cc22ada2fce@cox.net/
Fixes: 45e833f0 ("scsi: message: fusion: Replace deprecated strncpy() with strscpy()")
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240410023155.2100422-2-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces. A good alternative is strscpy() as it guarantees
NUL-termination on the destination buffer.

In crypto.c:
We expect cipher_name to be NUL-terminated based on its use with
the C-string format specifier %s and with other string apis like
strlen():
|	printk(KERN_ERR "Error attempting to initialize key TFM "
|		"cipher with name = [%s]; rc = [%d]\n",
|		tmp_tfm->cipher_name, rc);
and
|	int cipher_name_len = strlen(cipher_name);

In main.c:
We can remove the manual NUL-byte assignments as well as the pointers to
destinations (which I assume only existed to trim down on line length?)
in favor of directly using the destination buffer which allows the
compiler to get size information -- enabling the usage of the new
2-argument strscpy().

Note that this patch relies on the _new_ 2-argument versions of
strscpy() and strscpy_pad() introduced in Commit e6584c39 ("string:
Allow 2-argument strscpy()").

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc:  <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240321-strncpy-fs-ecryptfs-crypto-c-v1-1-d78b74c214ac@google.comSigned-off-by: Kees Cook <keescook@chromium.org>

strncpy() is deprecated with NUL-terminated destination strings [1].

The copy_name() method does a lot of manual buffer manipulation to
eventually arrive with its desired string. If we don't know the
namespace this attr has or belongs to we want to prepend "osx." to our
final string. Following this, we're copying xattr_name and doing a
bizarre manual NUL-byte assignment with a memset where n=1.

Really, we can use some more obvious string APIs to acomplish this,
improving readability and security. Following the same control flow as
before: if we don't know the namespace let's use scnprintf() to form our
prefix + xattr_name pairing (while NUL-terminating too!). Otherwise, use
strscpy() to return the number of bytes copied into our buffer.
Additionally, for non-empty strings, include the NUL-byte in the length
-- matching the behavior of the previous implementation.

Note that strscpy() _can_ return -E2BIG but this is already handled by
all callsites:

In both hfsplus_listxattr_finder_info() and hfsplus_listxattr(), ret is
already type ssize_t so we can change the return type of copy_name() to
match (understanding that scnprintf()'s return type is different yet
fully representable by ssize_t). Furthermore, listxattr() in fs/xattr.c
is well-equipped to handle a potential -E2BIG return result from
vfs_listxattr():
|	ssize_t error;
...
|	error = vfs_listxattr(d, klist, size);
|	if (error > 0) {
|		if (size && copy_to_user(list, klist, error))
|			error = -EFAULT;
|	} else if (error == -ERANGE && size >= XATTR_LIST_MAX) {
|		/* The file system tried to returned a list bigger
|			than XATTR_LIST_MAX bytes. Not possible. */
|		error = -E2BIG;
|	}
... the error can potentially already be -E2BIG, skipping this else-if
and ending up at the same state as other errors.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90
Cc:  <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240401-strncpy-fs-hfsplus-xattr-c-v2-1-6e089999355e@google.comSigned-off-by: Kees Cook <keescook@chromium.org>

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

Our goal here is to get @namebuf populated with @name's contents but
surrounded with quotes. There is some careful handling done to ensure we
properly truncate @name so that we have room for a literal quote as well
as a NUL-term. All this careful handling can be done with scnprintf
using the dynamic string width specifier %.*s which allows us to pass in
the max size for a source string. Doing this, we can put literal quotes
in our format specifier and ensure @name is truncated to fit inbetween
these quotes (-3 is from 2 quotes + 1 NUL-byte).

All in all, we get to remove a deprecated use of strncpy and clean up
this code nicely!

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc:  <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240328-strncpy-fs-reiserfs-item_ops-c-v1-1-2dab6d22a996@google.comSigned-off-by: Kees Cook <keescook@chromium.org>

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We can see that client->name should be NUL-terminated based on its usage
with a %s C-string format specifier.
|	client->thread = kthread_run(ioreq_task, client, "VM%u-%s",
|					client->vm->vmid, client->name);

NUL-padding is not required as client is already zero-allocated:
|	client = kzalloc(sizeof(*client), GFP_KERNEL);

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

Note that this patch relies on the _new_ 2-argument version of strscpy()
introduced in Commit e6584c39 ("string: Allow 2-argument
strscpy()").

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc:  <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240320-strncpy-drivers-virt-acrn-ioreq-c-v1-1-db6996770341@google.comSigned-off-by: Kees Cook <keescook@chromium.org>

When generating Runtime Calls, Clang doesn't respect the -mregparm=3
option used on i386. Hopefully this will be fixed correctly in Clang 19:
https://github.com/llvm/llvm-project/pull/89707
but we need to fix this for earlier Clang versions today. Force the
calling convention to use non-register arguments.
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Closes: https://github.com/KSPP/linux/issues/350
Link: https://lore.kernel.org/r/20240424224026.it.216-kees@kernel.orgAcked-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

The "type_name" character array was still marked as a 1-element array.
While we don't validate strings used in format arguments yet, let's fix
this before it causes trouble some future day.

Link: https://lore.kernel.org/r/20240424162739.work.492-kees@kernel.orgReviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

The "ubsan.h" file was missed in the creation of the UBSAN section. Add
it.

Link: https://lore.kernel.org/r/20240424162722.work.576-kees@kernel.orgAcked-by: Marco Elver <elver@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

It is more logical to have the strtomem() test in string_kunit.c instead
of the memcpy() suite. Move it to live with memtostr().
Signed-off-by: Kees Cook <keescook@chromium.org>

Another ambiguous use of strncpy() is to copy from strings that may not
be NUL-terminated. These cases depend on having the destination buffer
be explicitly larger than the source buffer's maximum size, having
the size of the copy exactly match the source buffer's maximum size,
and for the destination buffer to get explicitly NUL terminated.

This usually happens when parsing protocols or hardware character arrays
that are not guaranteed to be NUL-terminated. The code pattern is
effectively this:

	char dest[sizeof(src) + 1];

	strncpy(dest, src, sizeof(src));
	dest[sizeof(dest) - 1] = '\0';

In practice it usually looks like:

struct from_hardware {
	...
	char name[HW_NAME_SIZE] __nonstring;
	...
};

	struct from_hardware *p = ...;
	char name[HW_NAME_SIZE + 1];

	strncpy(name, p->name, HW_NAME_SIZE);
	name[NW_NAME_SIZE] = '\0';

This cannot be replaced with:

	strscpy(name, p->name, sizeof(name));

because p->name is smaller and not NUL-terminated, so FORTIFY will
trigger when strnlen(p->name, sizeof(name)) is used. And it cannot be
replaced with:

	strscpy(name, p->name, sizeof(p->name));

because then "name" may contain a 1 character early truncation of
p->name.

Provide an unambiguous interface for converting a maybe not-NUL-terminated
string to a NUL-terminated string, with compile-time buffer size checking
so that it can never fail at runtime: memtostr() and memtostr_pad(). Also
add KUnit tests for both.

Link: https://lore.kernel.org/r/20240410023155.2100422-1-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The KUnit convention for test names is AREA_test_WHAT. Adjust the string
test names to follow this pattern.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-5-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

Move the strcat() tests into string_kunit.c. Remove the separate
Kconfig and Makefile rule.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-4-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

The test naming convention differs between string_kunit.c and
strcat_kunit.c. Move "test" to the beginning of the function name.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-3-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

Move the strscpy() tests into string_kunit.c. Remove the separate
Kconfig and Makefile rule.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-2-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

In preparation for moving the strscpy_kunit.c tests into string_kunit.c,
rename "tc" to "strscpy_check" for better readability.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20240419140155.3028912-1-keescook@chromium.orgSigned-off-by: Kees Cook <keescook@chromium.org>

Currently, str*cmp functions (strcmp, strncmp, strcasecmp and
strncasecmp) are not covered with tests. Extend the `string_kunit.c`
test by adding the test cases for them.

This patch adds 8 more test cases:

1) strcmp test
2) strcmp test on long strings (2048 chars)
3) strncmp test
4) strncmp test on long strings (2048 chars)
5) strcasecmp test
6) strcasecmp test on long strings
7) strncasecmp test
8) strncasecmp test on long strings

These test cases aim at covering as many edge cases as possible,
including the tests on empty strings, situations when the different
symbol is placed at the end of one of the strings, etc.
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240417233033.717596-1-ivan.orlov0322@gmail.comSigned-off-by: Kees Cook <keescook@chromium.org>

Merge tag 'kbuild-fixes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Deduplicate Kconfig entries for CONFIG_CXL_PMU

 - Fix unselectable choice entry in MIPS Kconfig, and forbid this
   structure

 - Remove unused include/asm-generic/export.h

 - Fix a NULL pointer dereference bug in modpost

 - Enable -Woverride-init warning consistently with W=1

 - Drop KCSAN flags from *.mod.c files

* tag 'kbuild-fixes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: Fix typo HEIGTH to HEIGHT
  Documentation/llvm: Note s390 LLVM=1 support with LLVM 18.1.0 and newer
  kbuild: Disable KCSAN for autogenerated *.mod.c intermediaries
  kbuild: make -Woverride-init warnings more consistent
  modpost: do not make find_tosym() return NULL
  export.h: remove include/asm-generic/export.h
  kconfig: do not reparent the menu inside a choice block
  MIPS: move unselectable FIT_IMAGE_FDT_EPM5 out of the "System type" choice
  cxl: remove CONFIG_CXL_PMU entry in drivers/cxl/Kconfig

Pull EDAC fixes from Borislav Petkov:

 - Fix more issues in the AMD FMPM driver

* tag 'edac_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  RAS: Avoid build errors when CONFIG_DEBUG_FS=n
  RAS/AMD/FMPM: Safely handle saved records of various sizes
  RAS/AMD/FMPM: Avoid NULL ptr deref in get_saved_records()

Pull irq fixes from Borislav Petkov:

 - Fix an unused function warning on irqchip/irq-armada-370-xp

 - Fix the IRQ sharing with pinctrl-amd and ACPI OSL

* tag 'irq_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/armada-370-xp: Suppress unused-function warning
  genirq: Introduce IRQF_COND_ONESHOT and use it in pinctrl-amd

Pull x86 perf fixes from Borislav Petkov:

 - Define the correct set of default hw events on AMD Zen4

 - Use the correct stalled cycles PMCs on AMD Zen2 and newer

 - Fix detection of the LBR freeze feature on AMD

* tag 'perf_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/core: Define a proper ref-cycles event for Zen 4 and later
  perf/x86/amd/core: Update and fix stalled-cycles-* events for Zen 2 and later
  perf/x86/amd/lbr: Use freeze based on availability
  x86/cpufeatures: Add new word for scattered features

Pull timers update from Borislav Petkov:

 - Volunteer in Anna-Maria and Frederic as timers co-maintainers so that
   tglx can relax more :-P

* tag 'timers_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Add co-maintainers for time[rs]

Pull objtool fix from Borislav Petkov:

 - Fix a format specifier build error in objtool during an x32 build

* tag 'objtool_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix compile failure when using the x32 compiler

Pull x86 fixes from Borislav Petkov:

 - Make sure single object builds in arch/x86/virt/ ala
      make ... arch/x86/virt/vmx/tdx/seamcall.o
   work again

 - Do not do ROM range scans and memory validation when the kernel is
   running as a SEV-SNP guest as those can get problematic and, before
   that, are not really needed in such a guest

 - Exclude the build-time generated vdso-image-x32.o object from objtool
   validation and in particular the return sites in there due to a
   warning which fires when an unpatched return thunk is being used

 - Improve the NMI CPUs stall message to show additional information
   about the state of each CPU wrt the NMI handler

 - Enable gcc named address spaces support only on !KCSAN configs due to
   compiler options incompatibility

 - Revert a change which was trying to use GB pages for mapping regions
   only when the regions would be large enough but that change lead to
   kexec failing

 - A documentation fixlet

* tag 'x86_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Use obj-y to descend into arch/x86/virt/
  x86/sev: Skip ROM range scans and validation for SEV-SNP guests
  x86/vdso: Fix rethunk patching for vdso-image-x32.o too
  x86/nmi: Upgrade NMI backtrace stall checks & messages
  x86/percpu: Disable named address spaces for KCSAN
  Revert "x86/mm/ident_map: Use gbpages only where full GB page should be mapped."
  Documentation/x86: Fix title underline length

Fixed a typo in some variables where height was misspelled as heigth.
Signed-off-by: Isak Ellmer <isak01@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

As of the first s390 pull request during the 6.9 merge window,
commit 691632f0 ("Merge tag 's390-6.9-1' of
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux"), s390 can be
built with LLVM=1 when using LLVM 18.1.0, which is the first version
that has SystemZ support implemented in ld.lld and llvm-objcopy.

Update the supported architectures table in the Kbuild LLVM
documentation to note this explicitly to make it more discoverable by
users and other developers. Additionally, this brings s390 in line with
the rest of the architectures in the table, which all support LLVM=1.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

When KCSAN and CONSTRUCTORS are enabled, one can trigger the

  "Unpatched return thunk in use. This should not happen!"

catch-all warning.

Usually, when objtool runs on the .o objects, it does generate a section
.return_sites which contains all offsets in the objects to the return
thunks of the functions present there. Those return thunks then get
patched at runtime by the alternatives.

KCSAN and CONSTRUCTORS add this to the object file's .text.startup
section:

  -------------------
  Disassembly of section .text.startup:

  ...

  0000000000000010 <_sub_I_00099_0>:
    10:   f3 0f 1e fa             endbr64
    14:   e8 00 00 00 00          call   19 <_sub_I_00099_0+0x9>
                          15: R_X86_64_PLT32      __tsan_init-0x4
    19:   e9 00 00 00 00          jmp    1e <__UNIQUE_ID___addressable_cryptd_alloc_aead349+0x6>
                          1a: R_X86_64_PLT32      __x86_return_thunk-0x4
  -------------------

which, if it is built as a module goes through the intermediary stage of
creating a <module>.mod.c file which, when translated, receives a second
constructor:

  -------------------
  Disassembly of section .text.startup:

  0000000000000010 <_sub_I_00099_0>:
    10:   f3 0f 1e fa             endbr64
    14:   e8 00 00 00 00          call   19 <_sub_I_00099_0+0x9>
                          15: R_X86_64_PLT32      __tsan_init-0x4
    19:   e9 00 00 00 00          jmp    1e <_sub_I_00099_0+0xe>
                          1a: R_X86_64_PLT32      __x86_return_thunk-0x4

  ...

  0000000000000030 <_sub_I_00099_0>:
    30:   f3 0f 1e fa             endbr64
    34:   e8 00 00 00 00          call   39 <_sub_I_00099_0+0x9>
                          35: R_X86_64_PLT32      __tsan_init-0x4
    39:   e9 00 00 00 00          jmp    3e <__ksymtab_cryptd_alloc_ahash+0x2>
                          3a: R_X86_64_PLT32      __x86_return_thunk-0x4
  -------------------

in the .ko file.

Objtool has run already so that second constructor's return thunk cannot
be added to the .return_sites section and thus the return thunk remains
unpatched and the warning rightfully fires.

Drop KCSAN flags from the mod.c generation stage as those constructors
do not contain data races one would be interested about.

Debugged together with David Kaplan <David.Kaplan@amd.com> and Nikolay
Borisov <nik.borisov@suse.com>.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Closes: https://lore.kernel.org/r/0851a207-7143-417e-be31-8bf2b3afb57d@molgen.mpg.deSigned-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> # Dell XPS 13
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The -Woverride-init warn about code that may be intentional or not,
but the inintentional ones tend to be real bugs, so there is a bit of
disagreement on whether this warning option should be enabled by default
and we have multiple settings in scripts/Makefile.extrawarn as well as
individual subsystems.

Older versions of clang only supported -Wno-initializer-overrides with
the same meaning as gcc's -Woverride-init, though all supported versions
now work with both. Because of this difference, an earlier cleanup of
mine accidentally turned the clang warning off for W=1 builds and only
left it on for W=2, while it's still enabled for gcc with W=1.

There is also one driver that only turns the warning off for newer
versions of gcc but not other compilers, and some but not all the
Makefiles still use a cc-disable-warning conditional that is no
longer needed with supported compilers here.

Address all of the above by removing the special cases for clang
and always turning the warning off unconditionally where it got
in the way, using the syntax that is supported by both compilers.

Fixes: 2cd3271b ("kbuild: avoid duplicate warning options")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>