The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20241202-sysfs-const-bin_attr-x86-v1-1-b767d5f0ac5c@weissschuh.net
All writes to the page now happen before it gets marked as executable
(or after it's already switched to the identmap page tables where it's
OK to be RWX).
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20241205153343.3275139-14-dwmw2@infradead.org
The memory encryption flag is passed in %r8 because that's where the
calling convention puts it. Instead of moving it to %r12 and then using
%r8 for other things, just leave it in %r8 and use other registers
instead.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-13-dwmw2@infradead.org
All writes to the relocate_kernel control page are now done *after* the
%cr3 switch via simple %rip-relative addressing, which means the DATA()
macro with its pointer arithmetic can also now be removed.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-12-dwmw2@infradead.org
The kernel's virtual mapping of the relocate_kernel page currently needs
to be RWX because it is written to before the %cr3 switch.
Now that the relocate_kernel page has its own .data section and local
variables, it can also have *global* variables. So eliminate the separate
page_list argument, and write the same information directly to variables
in the relocate_kernel page instead. This way, the relocate_kernel code
itself doesn't need to copy it.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-11-dwmw2@infradead.org
Now that the relocate_kernel page is handled sanely by a linker script
we can have actual data, and just use %rip-relative addressing to access
it.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-10-dwmw2@infradead.org
Now that the copy is executed instead of the original, the relocate_kernel
page can live in the kernel's .text section. This will allow subsequent
commits to actually add real data to it and clean up the code somewhat as
well as making the control page ROX.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-9-dwmw2@infradead.org
This currently calls set_memory_x() from machine_kexec_prepare() just
like the 32-bit version does. That's actually a bit earlier than I'd
like, as it leaves the page RWX all the time the image is even *loaded*.
Subsequent commits will eliminate all the writes to the page between the
point it's marked executable in machine_kexec_prepare() the time that
relocate_kernel() is running and has switched to the identmap %cr3, so
that it can be ROX. But that can't happen until it's moved to the .data
section of the kernel, and *that* can't happen until we start executing
the copy instead of executing it in place in the kernel .text. So break
the circular dependency in those commits by letting it be RWX for now.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-8-dwmw2@infradead.org
There's no need for this to wait until the actual machine_kexec() invocation;
future changes will need to make the control page read-only and executable,
so all writes should be completed before machine_kexec_prepare() returns.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-7-dwmw2@infradead.org
Now that the following fix:
d0ceea662d ("x86/mm: Add _PAGE_NOPTISHADOW bit to avoid updating userspace page tables")
stops kernel_ident_mapping_init() from scribbling over the end of a
4KiB PGD by assuming the following 4KiB will be a userspace PGD,
there's no good reason for the kexec PGD to be part of a single
8KiB allocation with the control_code_page.
( It's not clear that that was the reason for x86_64 kexec doing it that
way in the first place either; there were no comments to that effect and
it seems to have been the case even before PTI came along. It looks like
it was just a happy accident which prevented memory corruption on kexec. )
Either way, it definitely isn't needed now. Just allocate the PGD
separately on x86_64, like i386 already does.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-6-dwmw2@infradead.org
There's no need to swap pages (which involves three memcopies for each
page) in the plain kexec case. Just do a single copy from source to
destination page.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-5-dwmw2@infradead.org
Make the code a little more readable.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Kai Huang <kai.huang@intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-4-dwmw2@infradead.org
Add more comments explaining what each register contains, and save the
preserve_context flag to a non-clobbered register sooner, to keep things
simpler.
No change in behavior intended.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Kai Huang <kai.huang@intel.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205153343.3275139-3-dwmw2@infradead.org
The restore_processor_state() function explicitly states that "the asm code
that gets us here will have restored a usable GDT". That wasn't true in the
case of returning from a ::preserve_context kexec. Make it so.
Without this, the kernel was depending on the called function to reload a
GDT which is appropriate for the kernel before returning.
Test program:
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/kexec.h>
#include <linux/reboot.h>
#include <sys/reboot.h>
#include <sys/syscall.h>
int main (void)
{
struct kexec_segment segment = {};
unsigned char purgatory[] = {
0x66, 0xba, 0xf8, 0x03, // mov $0x3f8, %dx
0xb0, 0x42, // mov $0x42, %al
0xee, // outb %al, (%dx)
0xc3, // ret
};
int ret;
segment.buf = &purgatory;
segment.bufsz = sizeof(purgatory);
segment.mem = (void *)0x400000;
segment.memsz = 0x1000;
ret = syscall(__NR_kexec_load, 0x400000, 1, &segment, KEXEC_PRESERVE_CONTEXT);
if (ret) {
perror("kexec_load");
exit(1);
}
ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_KEXEC);
if (ret) {
perror("kexec reboot");
exit(1);
}
printf("Success\n");
return 0;
}
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241205153343.3275139-2-dwmw2@infradead.org
The rework of possible CPUs management erroneously disabled SMP when the
IO/APIC is disabled either by the 'noapic' command line parameter or during
IO/APIC setup. SMP is possible without IO/APIC.
Remove the ioapic_is_disabled conditions from the relevant possible CPU
management code paths to restore the orgininal behaviour.
Fixes: 7c0edad364 ("x86/cpu/topology: Rework possible CPU management")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241202145905.1482-1-ffmancera@riseup.net
The .head.text section used to contain asm code that bootstrapped the
page tables and switched to the kernel virtual address space before
executing C code. The asm code carefully avoided dereferencing absolute
symbol references, as those will fault before the page tables are
installed.
Today, the .head.text section contains lots of C code too, and getting
the compiler to reason about absolute addresses taken from, e.g.,
section markers such as _text[] or _end[] but never use such absolute
references to access global variables [*] is intractible.
So instead, forbid the use of absolute references in .head.text
entirely, and rely on explicit arithmetic involving VA-to-PA offsets
generated by the asm startup code to construct virtual addresses where
needed (e.g., to construct the page tables).
Note that the 'relocs' tool is only used on the core kernel image when
building a relocatable image, but this is the default, and so adding the
check there is sufficient to catch new occurrences of code that use
absolute references before the kernel mapping is up.
[*] it is feasible when using PIC codegen but there is strong pushback
to using this for all of the core kernel, and using it only for
.head.text is not straight-forward.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-16-ardb+git@google.com
In order to be able to double check that vmlinux is emitted without
absolute symbol references in .head.text, it needs to be distinguishable
from the rest of .text in the ELF metadata.
So move .head.text into its own ELF section.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-15-ardb+git@google.com
Since commit:
7734a0f31e ("x86/boot: Robustify calling startup_{32,64}() from the decompressor code")
it is no longer necessary for .head.text to appear at the start of the
image. Since ENTRY_TEXT needs to appear PMD-aligned, it is easier to
just place it at the start of the image, rather than line it up with the
end of the .text section. The amount of padding required should be the
same, but this arrangement also permits .head.text to be split off and
emitted separately, which is needed by a subsequent change.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-14-ardb+git@google.com
The early boot code runs from a 1:1 mapping of memory, and may execute
before the kernel virtual mapping is even up. This means absolute symbol
references cannot be permitted in this code.
UBSAN injects references to global data structures into the code, and
without -fPIC, those references are emitted as absolute references to
kernel virtual addresses. Accessing those will fault before the kernel
virtual mapping is up, so UBSAN needs to be disabled in early boot code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-13-ardb+git@google.com
The code in .head.text executes from a 1:1 mapping and cannot generally
refer to global variables using their kernel virtual addresses. However,
there are some occurrences of such references that are valid: the kernel
virtual addresses of _text and _end are needed to populate the page
tables correctly, and some other section markers are used in a similar
way.
To avoid the need for making exceptions to the rule that .head.text must
not contain any absolute symbol references, derive these addresses from
the RIP-relative 1:1 mapped physical addresses, which can be safely
determined using RIP_REL_REF().
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-12-ardb+git@google.com
Implicit absolute symbol references (e.g., taking the address of a
global variable) must be avoided in the C code that runs from the early
1:1 mapping of the kernel, given that this is a practice that violates
assumptions on the part of the toolchain. I.e., RIP-relative and
absolute references are expected to produce the same values, and so the
compiler is free to choose either. However, the code currently assumes
that RIP-relative references are never emitted here.
So an explicit virtual-to-physical offset needs to be used instead to
derive the kernel virtual addresses of _text and _end, instead of simply
taking the addresses and assuming that the compiler will not choose to
use a RIP-relative references in this particular case.
Currently, phys_base is already used to perform such calculations, but
it is derived from the kernel virtual address of _text, which is taken
using an implicit absolute symbol reference. So instead, derive this
VA-to-PA offset in asm code, and pass it to the C startup code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-11-ardb+git@google.com
Using WARN() or panic() while executing from the early 1:1 mapping is
unlikely to do anything useful: the string literals are passed using
their kernel virtual addresses which are not even mapped yet. But even
if they were, calling into the printk() machinery from the early 1:1
mapped code is not going to get very far.
So drop the WARN()s entirely, and replace panic() with a deadloop.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-10-ardb+git@google.com
The set_p4d() and set_pgd() functions (in 4-level or 5-level page table setups
respectively) assume that the root page table is actually a 8KiB allocation,
with the userspace root immediately after the kernel root page table (so that
the former can enforce NX on on all the subordinate page tables, which are
actually shared).
However, users of the kernel_ident_mapping_init() code do not give it an 8KiB
allocation for its PGD. Both swsusp_arch_resume() and acpi_mp_setup_reset()
allocate only a single 4KiB page. The kexec code on x86_64 currently gets
away with it purely by chance, because it allocates 8KiB for its "control
code page" and then actually uses the first half for the PGD, then copies the
actual trampoline code into the second half only after the identmap code has
finished scribbling over it.
Fix this by defining a _PAGE_NOPTISHADOW bit (which can use the same bit as
_PAGE_SAVED_DIRTY since one is only for the PGD/P4D root and the other is
exclusively for leaf PTEs.). This instructs __pti_set_user_pgtbl() not to
write to the userspace 'shadow' PGD.
Strictly, the _PAGE_NOPTISHADOW bit doesn't need to be written out to the
actual page tables; since __pti_set_user_pgtbl() returns the value to be
written to the kernel page table, it could be filtered out. But there seems
to be no benefit to actually doing so.
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/412c90a4df7aef077141d9f68d19cbe5602d6c6d.camel@infradead.org
Cc: stable@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Under some conditions, MONITOR wakeups on Lunar Lake processors
can be lost, resulting in significant user-visible delays.
Add Lunar Lake to X86_BUG_MONITOR so that wake_up_idle_cpu()
always sends an IPI, avoiding this potential delay.
Reported originally here:
https://bugzilla.kernel.org/show_bug.cgi?id=219364
[ dhansen: tweak subject ]
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown%40intel.com
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Merge tag 'for-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- add lockdep annotations for io_uring/encoded read integration, inode
lock is held when returning to userspace
- properly reflect experimental config option to sysfs
- handle NULL root in case the rescue mode accepts invalid/damaged tree
roots (rescue=ibadroot)
- regression fix of a deadlock between transaction and extent locks
- fix pending bio accounting bug in encoded read ioctl
- fix NOWAIT mode when checking references for NOCOW files
- fix use-after-free in a rb-tree cleanup in ref-verify debugging tool
* tag 'for-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix lockdep warnings on io_uring encoded reads
btrfs: ref-verify: fix use-after-free after invalid ref action
btrfs: add a sanity check for btrfs root in btrfs_search_slot()
btrfs: don't loop for nowait writes when checking for cross references
btrfs: sysfs: advertise experimental features only if CONFIG_BTRFS_EXPERIMENTAL=y
btrfs: fix deadlock between transaction commits and extent locks
btrfs: fix use-after-free in btrfs_encoded_read_endio()
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Merge tag 'fs_for_v6.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull quota and udf fixes from Jan Kara:
"Two small UDF fixes for better handling of corrupted filesystem and a
quota fix to fix handling of filesystem freezing"
* tag 'fs_for_v6.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
udf: Verify inode link counts before performing rename
udf: Skip parent dir link count update if corrupted
quota: flush quota_release_work upon quota writeback
* Use xchg() in xlog_cil_insert_pcp_aggregate()
* Fix ABBA deadlock on a race between mount and log shutdown
* Fix quota softlimit incoherency on delalloc
* Fix sparse inode limits on runt AG
* remove unknown compat feature checks in SB write valdation
* Eliminate a lockdep false positive
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Merge tag 'xfs-fixes-6.13-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Carlos Maiolino:
- Use xchg() in xlog_cil_insert_pcp_aggregate()
- Fix ABBA deadlock on a race between mount and log shutdown
- Fix quota softlimit incoherency on delalloc
- Fix sparse inode limits on runt AG
- remove unknown compat feature checks in SB write valdation
- Eliminate a lockdep false positive
* tag 'xfs-fixes-6.13-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: don't call xfs_bmap_same_rtgroup in xfs_bmap_add_extent_hole_delay
xfs: Use xchg() in xlog_cil_insert_pcp_aggregate()
xfs: prevent mount and log shutdown race
xfs: delalloc and quota softlimit timers are incoherent
xfs: fix sparse inode limits on runt AG
xfs: remove unknown compat feature check in superblock write validation
xfs: eliminate lockdep false positives in xfs_attr_shortform_list
Commit cdd30ebb1b ("module: Convert symbol namespace to string
literal") only converted MODULE_IMPORT_NS() and EXPORT_SYMBOL_NS(),
leaving DEFAULT_SYMBOL_NAMESPACE as a macro expansion.
This commit converts DEFAULT_SYMBOL_NAMESPACE in the same way to avoid
annoyance for the default namespace as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts the misconversions introduced by commit cdd30ebb1b
("module: Convert symbol namespace to string literal").
The affected descriptions refer to MODULE_IMPORT_NS() tags in general,
rather than suggesting the use of the empty string ("") as the
namespace.
Fixes: cdd30ebb1b ("module: Convert symbol namespace to string literal")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit cdd30ebb1b ("module: Convert symbol namespace to string
literal"), when MODULE_IMPORT_NS() is missing, 'make nsdeps' inserts
pointless code:
MODULE_IMPORT_NS("ns");
Here, "ns" is not a namespace, but the variable in the semantic patch.
It must not be quoted. Instead, a string literal must be passed to
Coccinelle.
Fixes: cdd30ebb1b ("module: Convert symbol namespace to string literal")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When XSTATE_BV[i] is 0, and XRSTOR attempts to restore state component
'i' it ignores any value in the XSAVE buffer and instead restores the
state component's init value.
This means that if XSAVE writes XSTATE_BV[PKRU]=0 then XRSTOR will
ignore the value that update_pkru_in_sigframe() writes to the XSAVE buffer.
XSTATE_BV[PKRU] only gets written as 0 if PKRU is in its init state. On
Intel CPUs, basically never happens because the kernel usually
overwrites the init value (aside: this is why we didn't notice this bug
until now). But on AMD, the init tracker is more aggressive and will
track PKRU as being in its init state upon any wrpkru(0x0).
Unfortunately, sig_prepare_pkru() does just that: wrpkru(0x0).
This writes XSTATE_BV[PKRU]=0 which makes XRSTOR ignore the PKRU value
in the sigframe.
To fix this, always overwrite the sigframe XSTATE_BV with a value that
has XSTATE_BV[PKRU]==1. This ensures that XRSTOR will not ignore what
update_pkru_in_sigframe() wrote.
The problematic sequence of events is something like this:
Userspace does:
* wrpkru(0xffff0000) (or whatever)
* Hardware sets: XINUSE[PKRU]=1
Signal happens, kernel is entered:
* sig_prepare_pkru() => wrpkru(0x00000000)
* Hardware sets: XINUSE[PKRU]=0 (aggressive AMD init tracker)
* XSAVE writes most of XSAVE buffer, including
XSTATE_BV[PKRU]=XINUSE[PKRU]=0
* update_pkru_in_sigframe() overwrites PKRU in XSAVE buffer
... signal handling
* XRSTOR sees XSTATE_BV[PKRU]==0, ignores just-written value
from update_pkru_in_sigframe()
Fixes: 70044df250 ("x86/pkeys: Update PKRU to enable all pkeys before XSAVE")
Suggested-by: Rudi Horn <rudi.horn@oracle.com>
Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20241119174520.3987538-3-aruna.ramakrishna%40oracle.com
update_pkru_in_sigframe() will shortly need some information which
is only available inside xsave_to_user_sigframe(). Move
update_pkru_in_sigframe() inside the other function to make it
easier to provide it that information.
No functional changes.
Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20241119174520.3987538-2-aruna.ramakrishna%40oracle.com
The continual trickle of small conversion patches is grating on me, and
is really not helping. Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:
/*
* .remove_new() is a relic from a prototype conversion of .remove().
* New drivers are supposed to implement .remove(). Once all drivers are
* converted to not use .remove_new any more, it will be dropped.
*/
This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.
I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.
Then I just removed the old (sic) .remove_new member function, and this
is the end result. No more unnecessary conversion noise.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
core: add of based component probing
Some devices are designed and manufactured with some components having
multiple drop-in replacement options. These components are often
connected to the mainboard via ribbon cables, having the same signals
and pin assignments across all options. These may include the display
panel and touchscreen on laptops and tablets, and the trackpad on
laptops. Sometimes which component option is used in a particular device
can be detected by some firmware provided identifier, other times that
information is not available, and the kernel has to try to probe each
device.
Instead of a delicate dance between drivers and device tree quirks, this
change introduces a simple I2C component probe function. For a given
class of devices on the same I2C bus, it will go through all of them,
doing a simple I2C read transfer and see which one of them responds. It
will then enable the device that responds.
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Merge tag 'i2c-for-6.13-rc1-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c component probing support from Wolfram Sang:
"Add OF component probing.
Some devices are designed and manufactured with some components having
multiple drop-in replacement options. These components are often
connected to the mainboard via ribbon cables, having the same signals
and pin assignments across all options. These may include the display
panel and touchscreen on laptops and tablets, and the trackpad on
laptops. Sometimes which component option is used in a particular
device can be detected by some firmware provided identifier, other
times that information is not available, and the kernel has to try to
probe each device.
Instead of a delicate dance between drivers and device tree quirks,
this change introduces a simple I2C component probe function. For a
given class of devices on the same I2C bus, it will go through all of
them, doing a simple I2C read transfer and see which one of them
responds. It will then enable the device that responds"
* tag 'i2c-for-6.13-rc1-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
MAINTAINERS: fix typo in I2C OF COMPONENT PROBER
of: base: Document prefix argument for of_get_next_child_with_prefix()
i2c: Fix whitespace style issue
arm64: dts: mediatek: mt8173-elm-hana: Mark touchscreens and trackpads as fail
platform/chrome: Introduce device tree hardware prober
i2c: of-prober: Add GPIO support to simple helpers
i2c: of-prober: Add simple helpers for regulator support
i2c: Introduce OF component probe function
of: base: Add for_each_child_of_node_with_prefix()
of: dynamic: Add of_changeset_update_prop_string
- Remove unused bprintf() function
bprintf() was added with the rest of the "bin-printf" functions.
These are functions that are used by trace_printk() that allows to
quickly save the format and arguments into the ring buffer without
the expensive processing of converting numbers to ASCII. Then on
output, at a much later time, the ring buffer is read and the string
processing occurs then. The bprintf() was added for consistency but
was never used. It can be safely removed.
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Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull bprintf() removal from Steven Rostedt:
- Remove unused bprintf() function, that was added with the rest of the
"bin-printf" functions.
These are functions that are used by trace_printk() that allows to
quickly save the format and arguments into the ring buffer without
the expensive processing of converting numbers to ASCII. Then on
output, at a much later time, the ring buffer is read and the string
processing occurs then. The bprintf() was added for consistency but
was never used. It can be safely removed.
* tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
printf: Remove unused 'bprintf'
signals if some of the group's threads are exiting
- Fix a hang caused by ndelay() calling the wrong delay function __udelay()
- Fix a wrong offset calculation in adjtimex(2) when using ADJ_MICRO
(microsecond resolution) and a negative offset
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Merge tag 'timers_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Borislav Petkov:
- Fix a case where posix timers with a thread-group-wide target would
miss signals if some of the group's threads are exiting
- Fix a hang caused by ndelay() calling the wrong delay function
__udelay()
- Fix a wrong offset calculation in adjtimex(2) when using ADJ_MICRO
(microsecond resolution) and a negative offset
* tag 'timers_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-timers: Target group sigqueue to current task only if not exiting
delay: Fix ndelay() spuriously treated as udelay()
ntp: Remove invalid cast in time offset math
fix some Marvell Armada platforms
- Add a workaround for Hisilicon ITS erratum 162100801 which can cause some
virtual interrupts to get lost
- More platform_driver::remove() conversion
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Merge tag 'irq_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Borislav Petkov:
- Move the ->select callback to the correct ops structure in
irq-mvebu-sei to fix some Marvell Armada platforms
- Add a workaround for Hisilicon ITS erratum 162100801 which can cause
some virtual interrupts to get lost
- More platform_driver::remove() conversion
* tag 'irq_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip: Switch back to struct platform_driver::remove()
irqchip/gicv3-its: Add workaround for hip09 ITS erratum 162100801
irqchip/irq-mvebu-sei: Move misplaced select() callback to SEI CP domain
by erratum 1386 so that the matching loop actually terminates instead of
going off into the weeds
- Update the boot protocol documentation to mention the fact that the
preferred address to load the kernel to is considered in the relocatable
kernel case too
- Flush the memory buffer containing the microcode patch after applying
microcode on AMD Zen1 and Zen2, to avoid unnecessary slowdowns
- Make sure the PPIN CPU feature flag is cleared on all CPUs if PPIN has been
disabled
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Merge tag 'x86_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Add a terminating zero end-element to the array describing AMD CPUs
affected by erratum 1386 so that the matching loop actually
terminates instead of going off into the weeds
- Update the boot protocol documentation to mention the fact that the
preferred address to load the kernel to is considered in the
relocatable kernel case too
- Flush the memory buffer containing the microcode patch after applying
microcode on AMD Zen1 and Zen2, to avoid unnecessary slowdowns
- Make sure the PPIN CPU feature flag is cleared on all CPUs if PPIN
has been disabled
* tag 'x86_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/CPU/AMD: Terminate the erratum_1386_microcode array
x86/Documentation: Update algo in init_size description of boot protocol
x86/microcode/AMD: Flush patch buffer mapping after application
x86/mm: Carve out INVLPG inline asm for use by others
x86/cpu: Fix PPIN initialization
The point behind strscpy() was to once and for all avoid all the
problems with 'strncpy()' and later broken "fixed" versions like
strlcpy() that just made things worse.
So strscpy not only guarantees NUL-termination (unlike strncpy), it also
doesn't do unnecessary padding at the destination. But at the same time
also avoids byte-at-a-time reads and writes by _allowing_ some extra NUL
writes - within the size, of course - so that the whole copy can be done
with word operations.
It is also stable in the face of a mutable source string: it explicitly
does not read the source buffer multiple times (so an implementation
using "strnlen()+memcpy()" would be wrong), and does not read the source
buffer past the size (like the mis-design that is strlcpy does).
Finally, the return value is designed to be simple and unambiguous: if
the string cannot be copied fully, it returns an actual negative error,
making error handling clearer and simpler (and the caller already knows
the size of the buffer). Otherwise it returns the string length of the
result.
However, there was one final stability issue that can be important to
callers: the stability of the destination buffer.
In particular, the same way we shouldn't read the source buffer more
than once, we should avoid doing multiple writes to the destination
buffer: first writing a potentially non-terminated string, and then
terminating it with NUL at the end does not result in a stable result
buffer.
Yes, it gives the right result in the end, but if the rule for the
destination buffer was that it is _always_ NUL-terminated even when
accessed concurrently with updates, the final byte of the buffer needs
to always _stay_ as a NUL byte.
[ Note that "final byte is NUL" here is literally about the final byte
in the destination array, not the terminating NUL at the end of the
string itself. There is no attempt to try to make concurrent reads and
writes give any kind of consistent string length or contents, but we
do want to guarantee that there is always at least that final
terminating NUL character at the end of the destination array if it
existed before ]
This is relevant in the kernel for the tsk->comm[] array, for example.
Even without locking (for either readers or writers), we want to know
that while the buffer contents may be garbled, it is always a valid C
string and always has a NUL character at 'comm[TASK_COMM_LEN-1]' (and
never has any "out of thin air" data).
So avoid any "copy possibly non-terminated string, and terminate later"
behavior, and write the destination buffer only once.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bprintf() is unused. Remove it. It was added in the commit 4370aa4aa7
("vsprintf: add binary printf") but as far as I can see was never used,
unlike the other two functions in that patch.
Link: https://lore.kernel.org/20241002173147.210107-1-linux@treblig.org
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Merge tag 'pci-v6.13-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI fix from Bjorn Helgaas:
- When removing a PCI device, only look up and remove a platform device
if there is an associated device node for which there could be a
platform device, to fix a merge window regression (Brian Norris)
* tag 'pci-v6.13-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI/pwrctrl: Unregister platform device only if one actually exists
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Merge tag 'lsm-pr-20241129' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull ima fix from Paul Moore:
"One small patch to fix a function parameter / local variable naming
snafu that went up to you in the current merge window"
* tag 'lsm-pr-20241129' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
ima: uncover hidden variable in ima_match_rules()
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Merge tag 'block-6.13-20242901' of git://git.kernel.dk/linux
Pull more block updates from Jens Axboe:
- NVMe pull request via Keith:
- Use correct srcu list traversal (Breno)
- Scatter-gather support for metadata (Keith)
- Fabrics shutdown race condition fix (Nilay)
- Persistent reservations updates (Guixin)
- Add the required bits for MD atomic write support for raid0/1/10
- Correct return value for unknown opcode in ublk
- Fix deadlock with zone revalidation
- Fix for the io priority request vs bio cleanups
- Use the correct unsigned int type for various limit helpers
- Fix for a race in loop
- Cleanup blk_rq_prep_clone() to prevent uninit-value warning and make
it easier for actual humans to read
- Fix potential UAF when iterating tags
- A few fixes for bfq-iosched UAF issues
- Fix for brd discard not decrementing the allocated page count
- Various little fixes and cleanups
* tag 'block-6.13-20242901' of git://git.kernel.dk/linux: (36 commits)
brd: decrease the number of allocated pages which discarded
block, bfq: fix bfqq uaf in bfq_limit_depth()
block: Don't allow an atomic write be truncated in blkdev_write_iter()
mq-deadline: don't call req_get_ioprio from the I/O completion handler
block: Prevent potential deadlock in blk_revalidate_disk_zones()
block: Remove extra part pointer NULLify in blk_rq_init()
nvme: tuning pr code by using defined structs and macros
nvme: introduce change ptpl and iekey definition
block: return bool from get_disk_ro and bdev_read_only
block: remove a duplicate definition for bdev_read_only
block: return bool from blk_rq_aligned
block: return unsigned int from blk_lim_dma_alignment_and_pad
block: return unsigned int from queue_dma_alignment
block: return unsigned int from bdev_io_opt
block: req->bio is always set in the merge code
block: don't bother checking the data direction for merges
block: blk-mq: fix uninit-value in blk_rq_prep_clone and refactor
Revert "block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()"
md/raid10: Atomic write support
md/raid1: Atomic write support
...
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Merge tag 'io_uring-6.13-20242901' of git://git.kernel.dk/linux
Pull more io_uring updates from Jens Axboe:
- Remove a leftover struct from when the cqwait registered waiting was
transitioned to regions.
- Fix for an issue introduced in this merge window, where nop->fd might
be used uninitialized. Ensure it's always set.
- Add capping of the task_work run in local task_work mode, to prevent
bursty and long chains from adding too much latency.
- Work around xa_store() leaving ->head non-NULL if it encounters an
allocation error during storing. Just a debug trigger, and can go
away once xa_store() behaves in a more expected way for this
condition. Not a major thing as it basically requires fault injection
to trigger it.
- Fix a few mapping corner cases
- Fix KCSAN complaint on reading the table size post unlock. Again not
a "real" issue, but it's easy to silence by just keeping the reading
inside the lock that protects it.
* tag 'io_uring-6.13-20242901' of git://git.kernel.dk/linux:
io_uring/tctx: work around xa_store() allocation error issue
io_uring: fix corner case forgetting to vunmap
io_uring: fix task_work cap overshooting
io_uring: check for overflows in io_pin_pages
io_uring/nop: ensure nop->fd is always initialized
io_uring: limit local tw done
io_uring: add io_local_work_pending()
io_uring/region: return negative -E2BIG in io_create_region()
io_uring: protect register tracing
io_uring: remove io_uring_cqwait_reg_arg
* Fixes.
RISC-V:
* Svade and Svadu (accessed and dirty bit) extension support for host and
guest. This was acked on the mailing list by the RISC-V maintainer, see
https://patchew.org/linux/20240726084931.28924-1-yongxuan.wang@sifive.com/.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more kvm updates from Paolo Bonzini:
- ARM fixes
- RISC-V Svade and Svadu (accessed and dirty bit) extension support for
host and guest
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list test
RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM
dt-bindings: riscv: Add Svade and Svadu Entries
RISC-V: Add Svade and Svadu Extensions Support
KVM: arm64: Use MDCR_EL2.HPME to evaluate overflow of hyp counters
KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status
KVM: arm64: Mark set_sysreg_masks() as inline to avoid build failure
KVM: arm64: vgic-its: Add stronger type-checking to the ITS entry sizes
KVM: arm64: vgic: Kill VGIC_MAX_PRIVATE definition
KVM: arm64: vgic: Make vgic_get_irq() more robust
KVM: arm64: vgic-v3: Sanitise guest writes to GICR_INVLPIR
