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git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
Pull LoongArch updates from Huacai Chen:
- Fix objtool about do_syscall() and Clang
- Enable generic CPU vulnerabilites support
- Enable ACPI BGRT handling
- Rework CPU feature probe from CPUCFG/IOCSR
- Add ARCH_HAS_SET_MEMORY support
- Add ARCH_HAS_SET_DIRECT_MAP support
- Improve hardware page table walker
- Simplify _percpu_read() and _percpu_write()
- Add advanced extended IRQ model documentions
- Some bug fixes and other small changes
* tag 'loongarch-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
Docs/LoongArch: Add advanced extended IRQ model description
LoongArch: Remove posix_types.h include from sigcontext.h
LoongArch: Fix memleak in pci_acpi_scan_root()
LoongArch: Simplify _percpu_read() and _percpu_write()
LoongArch: Improve hardware page table walker
LoongArch: Add ARCH_HAS_SET_DIRECT_MAP support
LoongArch: Add ARCH_HAS_SET_MEMORY support
LoongArch: Rework CPU feature probe from CPUCFG/IOCSR
LoongArch: Enable ACPI BGRT handling
LoongArch: Enable generic CPU vulnerabilites support
LoongArch: Remove STACK_FRAME_NON_STANDARD(do_syscall)
LoongArch: Set AS_HAS_THIN_ADD_SUB as y if AS_IS_LLVM
LoongArch: Enable objtool for Clang
objtool: Handle frame pointer related instructions
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After commit a0f7085f6a63 ("LoongArch: Add RANDOMIZE_KSTACK_OFFSET
support"), there are three new instructions "addi.d $fp, $sp, 32",
"sub.d $sp, $sp, $t0" and "addi.d $sp, $fp, -32" for the secondary
stack in do_syscall(), then there is a objtool warning "return with
modified stack frame" and no handle_syscall() which is the previous
frame of do_syscall() in the call trace when executing the command
"echo l > /proc/sysrq-trigger".
objdump shows something like this:
0000000000000000 <do_syscall>:
0: 02ff8063 addi.d $sp, $sp, -32
4: 29c04076 st.d $fp, $sp, 16
8: 29c02077 st.d $s0, $sp, 8
c: 29c06061 st.d $ra, $sp, 24
10: 02c08076 addi.d $fp, $sp, 32
...
74: 0011b063 sub.d $sp, $sp, $t0
...
a8: 4c000181 jirl $ra, $t0, 0
...
dc: 02ff82c3 addi.d $sp, $fp, -32
e0: 28c06061 ld.d $ra, $sp, 24
e4: 28c04076 ld.d $fp, $sp, 16
e8: 28c02077 ld.d $s0, $sp, 8
ec: 02c08063 addi.d $sp, $sp, 32
f0: 4c000020 jirl $zero, $ra, 0
The instruction "sub.d $sp, $sp, $t0" changes the stack bottom and the
new stack size is a random value, in order to find the return address of
do_syscall() which is stored in the original stack frame after executing
"jirl $ra, $t0, 0", it should use fp which points to the original stack
top.
At the beginning, the thought is tended to decode the secondary stack
instruction "sub.d $sp, $sp, $t0" and set it as a label, then check this
label for the two frame pointer instructions to change the cfa base and
cfa offset during the period of secondary stack in update_cfi_state().
This is valid for GCC but invalid for Clang due to there are different
secondary stack instructions for ClangBuiltLinux on LoongArch, something
like this:
0000000000000000 <do_syscall>:
...
88: 00119064 sub.d $a0, $sp, $a0
8c: 00150083 or $sp, $a0, $zero
...
Actually, it equals to a single instruction "sub.d $sp, $sp, $a0", but
there is no proper condition to check it as a label like GCC, and so the
beginning thought is not a good way.
Essentially, there are two special frame pointer instructions which are
"addi.d $fp, $sp, imm" and "addi.d $sp, $fp, imm", the first one points
fp to the original stack top and the second one restores the original
stack bottom from fp.
Based on the above analysis, in order to avoid adding an arch-specific
update_cfi_state(), we just add a member "frame_pointer" in the "struct
symbol" as a label to avoid affecting the current normal case, then set
it as true only if there is "addi.d $sp, $fp, imm". The last is to check
this label for the two frame pointer instructions to change the cfa base
and cfa offset in update_cfi_state().
Tested with the following two configs:
(1) CONFIG_RANDOMIZE_KSTACK_OFFSET=y &&
CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=n
(2) CONFIG_RANDOMIZE_KSTACK_OFFSET=y &&
CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y
By the way, there is no effect for x86 with this patch, tested on the
x86 machine with Fedora 40 system.
Cc: stable@vger.kernel.org # 6.9+
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Rust functions may be `noreturn` (i.e. diverging) by returning the
"never" type, `!`, e.g.
fn f() -> ! {
loop {}
}
Thus list the known `noreturn` functions to avoid such warnings.
Without this, `objtool` would complain if enabled for Rust, e.g.:
rust/core.o: warning: objtool:
_R...9panic_fmt() falls through to next function _R...18panic_nounwind_fmt()
rust/alloc.o: warning: objtool:
.text: unexpected end of section
In order to do so, we cannot match symbols' names exactly, for two
reasons:
- Rust mangling scheme [1] contains disambiguators [2] which we
cannot predict (e.g. they may vary depending on the compiler version).
One possibility to solve this would be to parse v0 and ignore/zero
those before comparison.
- Some of the diverging functions come from `core`, i.e. the Rust
standard library, which may change with each compiler version
since they are implementation details (e.g. `panic_internals`).
Thus, to workaround both issues, only part of the symbols are matched,
instead of using the `NORETURN` macro in `noreturns.h`.
Ideally, just like for the C side, we should have a better solution. For
instance, the compiler could give us the list via something like:
$ rustc --emit=noreturns ...
[ Kees agrees this should be automated and Peter says:
So it would be fairly simple to make objtool consume a magic section
emitted by the compiler.. I think we've asked the compiler folks
for that at some point even, but I don't have clear recollections.
We will ask upstream Rust about it. And if they agree, then perhaps
we can get Clang/GCC to implement something similar too -- for this
sort of thing we can take advantage of the shorter cycles of `rustc`
as well as their unstable features concept to experiment.
Gary proposed using DWARF (though it would need to be available), and
wrote a proof of concept script using the `object` and `gimli` crates:
https://gist.github.com/nbdd0121/449692570622c2f46a29ad9f47c3379a
- Miguel ]
Link: https://rust-lang.github.io/rfcs/2603-rust-symbol-name-mangling-v0.html [1]
Link: https://doc.rust-lang.org/rustc/symbol-mangling/v0.html#disambiguator [2]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240725183325.122827-6-ojeda@kernel.org
[ Added `len_mismatch_fail` symbol for new `kernel` crate code merged
since then as well as 3 more `core::panicking` symbols that appear
in `RUST_DEBUG_ASSERTIONS=y` builds. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- In the series "mm: Avoid possible overflows in dirty throttling" Jan
Kara addresses a couple of issues in the writeback throttling code.
These fixes are also targetted at -stable kernels.
- Ryusuke Konishi's series "nilfs2: fix potential issues related to
reserved inodes" does that. This should actually be in the
mm-nonmm-stable tree, along with the many other nilfs2 patches. My
bad.
- More folio conversions from Kefeng Wang in the series "mm: convert to
folio_alloc_mpol()"
- Kemeng Shi has sent some cleanups to the writeback code in the series
"Add helper functions to remove repeated code and improve readability
of cgroup writeback"
- Kairui Song has made the swap code a little smaller and a little
faster in the series "mm/swap: clean up and optimize swap cache
index".
- In the series "mm/memory: cleanly support zeropage in
vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
Hildenbrand has reworked the rather sketchy handling of the use of
the zeropage in MAP_SHARED mappings. I don't see any runtime effects
here - more a cleanup/understandability/maintainablity thing.
- Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
of higher addresses, for aarch64. The (poorly named) series is
"Restructure va_high_addr_switch".
- The core TLB handling code gets some cleanups and possible slight
optimizations in Bang Li's series "Add update_mmu_tlb_range() to
simplify code".
- Jane Chu has improved the handling of our
fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
the series "Enhance soft hwpoison handling and injection".
- Jeff Johnson has sent a billion patches everywhere to add
MODULE_DESCRIPTION() to everything. Some landed in this pull.
- In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
has simplified migration's use of hardware-offload memory copying.
- Yosry Ahmed performs more folio API conversions in his series "mm:
zswap: trivial folio conversions".
- In the series "large folios swap-in: handle refault cases first",
Chuanhua Han inches us forward in the handling of large pages in the
swap code. This is a cleanup and optimization, working toward the end
objective of full support of large folio swapin/out.
- In the series "mm,swap: cleanup VMA based swap readahead window
calculation", Huang Ying has contributed some cleanups and a possible
fixlet to his VMA based swap readahead code.
- In the series "add mTHP support for anonymous shmem" Baolin Wang has
taught anonymous shmem mappings to use multisize THP. By default this
is a no-op - users must opt in vis sysfs controls. Dramatic
improvements in pagefault latency are realized.
- David Hildenbrand has some cleanups to our remaining use of
page_mapcount() in the series "fs/proc: move page_mapcount() to
fs/proc/internal.h".
- David also has some highmem accounting cleanups in the series
"mm/highmem: don't track highmem pages manually".
- Build-time fixes and cleanups from John Hubbard in the series
"cleanups, fixes, and progress towards avoiding "make headers"".
- Cleanups and consolidation of the core pagemap handling from Barry
Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
and utilize them".
- Lance Yang's series "Reclaim lazyfree THP without splitting" has
reduced the latency of the reclaim of pmd-mapped THPs under fairly
common circumstances. A 10x speedup is seen in a microbenchmark.
It does this by punting to aother CPU but I guess that's a win unless
all CPUs are pegged.
- hugetlb_cgroup cleanups from Xiu Jianfeng in the series
"mm/hugetlb_cgroup: rework on cftypes".
- Miaohe Lin's series "Some cleanups for memory-failure" does just that
thing.
- Someone other than SeongJae has developed a DAMON feature in Honggyu
Kim's series "DAMON based tiered memory management for CXL memory".
This adds DAMON features which may be used to help determine the
efficiency of our placement of CXL/PCIe attached DRAM.
- DAMON user API centralization and simplificatio work in SeongJae
Park's series "mm/damon: introduce DAMON parameters online commit
function".
- In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
David Hildenbrand does some maintenance work on zsmalloc - partially
modernizing its use of pageframe fields.
- Kefeng Wang provides more folio conversions in the series "mm: remove
page_maybe_dma_pinned() and page_mkclean()".
- More cleanup from David Hildenbrand, this time in the series
"mm/memory_hotplug: use PageOffline() instead of PageReserved() for
!ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
pages" and permits the removal of some virtio-mem hacks.
- Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
__folio_add_anon_rmap()" is a cleanup to the anon folio handling in
preparation for mTHP (multisize THP) swapin.
- Kefeng Wang's series "mm: improve clear and copy user folio"
implements more folio conversions, this time in the area of large
folio userspace copying.
- The series "Docs/mm/damon/maintaier-profile: document a mailing tool
and community meetup series" tells people how to get better involved
with other DAMON developers. From SeongJae Park.
- A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
that.
- David Hildenbrand sends along more cleanups, this time against the
migration code. The series is "mm/migrate: move NUMA hinting fault
folio isolation + checks under PTL".
- Jan Kara has found quite a lot of strangenesses and minor errors in
the readahead code. He addresses this in the series "mm: Fix various
readahead quirks".
- SeongJae Park's series "selftests/damon: test DAMOS tried regions and
{min,max}_nr_regions" adds features and addresses errors in DAMON's
self testing code.
- Gavin Shan has found a userspace-triggerable WARN in the pagecache
code. The series "mm/filemap: Limit page cache size to that supported
by xarray" addresses this. The series is marked cc:stable.
- Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
and cleanup" cleans up and slightly optimizes KSM.
- Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
code motion. The series (which also makes the memcg-v1 code
Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
under config option" and "mm: memcg: put cgroup v1-specific memcg
data under CONFIG_MEMCG_V1"
- Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
adds an additional feature to this cgroup-v2 control file.
- The series "Userspace controls soft-offline pages" from Jiaqi Yan
permits userspace to stop the kernel's automatic treatment of
excessive correctable memory errors. In order to permit userspace to
monitor and handle this situation.
- Kefeng Wang's series "mm: migrate: support poison recover from
migrate folio" teaches the kernel to appropriately handle migration
from poisoned source folios rather than simply panicing.
- SeongJae Park's series "Docs/damon: minor fixups and improvements"
does those things.
- In the series "mm/zsmalloc: change back to per-size_class lock"
Chengming Zhou improves zsmalloc's scalability and memory
utilization.
- Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
pinning memfd folios" makes the GUP code use FOLL_PIN rather than
bare refcount increments. So these paes can first be moved aside if
they reside in the movable zone or a CMA block.
- Andrii Nakryiko has added a binary ioctl()-based API to
/proc/pid/maps for much faster reading of vma information. The series
is "query VMAs from /proc/<pid>/maps".
- In the series "mm: introduce per-order mTHP split counters" Lance
Yang improves the kernel's presentation of developer information
related to multisize THP splitting.
- Michael Ellerman has developed the series "Reimplement huge pages
without hugepd on powerpc (8xx, e500, book3s/64)". This permits
userspace to use all available huge page sizes.
- In the series "revert unconditional slab and page allocator fault
injection calls" Vlastimil Babka removes a performance-affecting and
not very useful feature from slab fault injection.
* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
mm/mglru: fix ineffective protection calculation
mm/zswap: fix a white space issue
mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
mm/hugetlb: fix possible recursive locking detected warning
mm/gup: clear the LRU flag of a page before adding to LRU batch
mm/numa_balancing: teach mpol_to_str about the balancing mode
mm: memcg1: convert charge move flags to unsigned long long
alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
lib: reuse page_ext_data() to obtain codetag_ref
lib: add missing newline character in the warning message
mm/mglru: fix overshooting shrinker memory
mm/mglru: fix div-by-zero in vmpressure_calc_level()
mm/kmemleak: replace strncpy() with strscpy()
mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
mm: ignore data-race in __swap_writepage
hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
mm: shmem: rename mTHP shmem counters
mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
mm/migrate: putback split folios when numa hint migration fails
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
- Fix bug that caused objtool to confuse certain memory ops added by
KASAN instrumentation as stack accesses
- Various faddr2line optimizations
- Improve error messages
* tag 'objtool-core-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool/x86: objtool can confuse memory and stack access
objtool: Use "action" in error message to be consistent with help
scripts/faddr2line: Check only two symbols when calculating symbol size
scripts/faddr2line: Remove call to addr2line from find_dir_prefix()
scripts/faddr2line: Invoke addr2line as a single long-running process
scripts/faddr2line: Pass --addresses argument to addr2line
scripts/faddr2line: Check vmlinux only once
scripts/faddr2line: Combine three readelf calls into one
scripts/faddr2line: Reduce number of readelf calls to three
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu mitigation updates from Borislav Petkov:
- Add a spectre_bhi=vmexit mitigation option aimed at cloud
environments
- Remove duplicated Spectre cmdline option documentation
- Add separate macro definitions for syscall handlers which do not
return in order to address objtool warnings
* tag 'x86_bugs_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bugs: Add 'spectre_bhi=vmexit' cmdline option
x86/bugs: Remove duplicate Spectre cmdline option descriptions
x86/syscall: Mark exit[_group] syscall handlers __noreturn
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Like for KASAN, it's useful to temporarily disable KMSAN checks around,
e.g., redzone accesses. Introduce kmsan_disable_current() and
kmsan_enable_current(), which are similar to their KASAN counterparts.
Make them reentrant in order to handle memory allocations in interrupt
context. Repurpose the allow_reporting field for this.
Link: https://lkml.kernel.org/r/20240621113706.315500-12-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The encoding of an x86 instruction can include a ModR/M and a SIB
(Scale-Index-Base) byte to describe the addressing mode of the
instruction.
objtool processes all addressing mode with a SIB base of 5 as having
%rbp as the base register. However, a SIB base of 5 means that the
effective address has either no base (if ModR/M mod is zero) or %rbp
as the base (if ModR/M mod is 1 or 2). This can cause objtool to confuse
an absolute address access with a stack operation.
For example, objtool will see the following instruction:
4c 8b 24 25 e0 ff ff mov 0xffffffffffffffe0,%r12
as a stack operation (i.e. similar to: mov -0x20(%rbp), %r12).
[Note that this kind of weird absolute address access is added by the
compiler when using KASAN.]
If this perceived stack operation happens to reference the location
where %r12 was pushed on the stack then the objtool validation will
think that %r12 is being restored and this can cause a stack state
mismatch.
This kind behavior was seen on xfs code, after a minor change (convert
kmem_alloc() to kmalloc()):
>> fs/xfs/xfs.o: warning: objtool: xfs_da_grow_inode_int+0x6c1: stack state mismatch: reg1[12]=-2-48 reg2[12]=-1+0
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402220435.MGN0EV6l-lkp@intel.com/
Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lore.kernel.org/r/20240620144747.2524805-1-alexandre.chartre@oracle.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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The help message mentions the main options as "actions", which is
different from the optional "options". But the check error messages
outputs "option" or "command" for referring to actions.
Make the error messages consistent with help.
Signed-off-by: Siddh Raman Pant <siddh.raman.pant@oracle.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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objtool complains:
arch/x86/kvm/kvm.o: warning: objtool: .altinstr_replacement+0xc5: call without frame pointer save/setup
vmlinux.o: warning: objtool: .altinstr_replacement+0x2eb: call without frame pointer save/setup
Make sure %rSP is an output operand to the respective asm() statements.
The test_cc() hunk and ALT_OUTPUT_SP() courtesy of peterz. Also from him
add some helpful debugging info to the documentation.
Now on to the explanations:
tl;dr: The alternatives macros are pretty fragile.
If I do ALT_OUTPUT_SP(output) in order to be able to package in a %rsp
reference for objtool so that a stack frame gets properly generated, the
inline asm input operand with positional argument 0 in clear_page():
"0" (page)
gets "renumbered" due to the added
: "+r" (current_stack_pointer), "=D" (page)
and then gcc says:
./arch/x86/include/asm/page_64.h:53:9: error: inconsistent operand constraints in an ‘asm’
The fix is to use an explicit "D" constraint which points to a singleton
register class (gcc terminology) which ends up doing what is expected
here: the page pointer - input and output - should be in the same %rdi
register.
Other register classes have more than one register in them - example:
"r" and "=r" or "A":
‘A’
The ‘a’ and ‘d’ registers. This class is used for
instructions that return double word results in the ‘ax:dx’
register pair. Single word values will be allocated either in
‘ax’ or ‘dx’.
so using "D" and "=D" just works in this particular case.
And yes, one would say, sure, why don't you do "+D" but then:
: "+r" (current_stack_pointer), "+D" (page)
: [old] "i" (clear_page_orig), [new1] "i" (clear_page_rep), [new2] "i" (clear_page_erms),
: "cc", "memory", "rax", "rcx")
now find the Waldo^Wcomma which throws a wrench into all this.
Because that silly macro has an "input..." consume-all last macro arg
and in it, one is supposed to supply input *and* clobbers, leading to
silly syntax snafus.
Yap, they need to be cleaned up, one fine day...
Closes: https://lore.kernel.org/oe-kbuild-all/202406141648.jO9qNGLa-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240625112056.GDZnqoGDXgYuWBDUwu@fat_crate.local
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The direct-call syscall dispatch function doesn't know that the exit()
and exit_group() syscall handlers don't return, so the call sites aren't
optimized accordingly.
Fix that by marking the exit syscall declarations __noreturn.
Fixes the following warnings:
vmlinux.o: warning: objtool: x64_sys_call+0x2804: __x64_sys_exit() is missing a __noreturn annotation
vmlinux.o: warning: objtool: ia32_sys_call+0x29b6: __ia32_sys_exit_group() is missing a __noreturn annotation
Fixes: 1e3ad78334a6 ("x86/syscall: Don't force use of indirect calls for system calls")
Closes: https://lkml.kernel.org/lkml/6dba9b32-db2c-4e6d-9500-7a08852f17a3@paulmck-laptop
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/5d8882bc077d8eadcc7fd1740b56dfb781f12288.1719381528.git.jpoimboe@kernel.org
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Instead of making increasingly complicated ALTERNATIVE_n()
implementations, use a nested alternative expression.
The only difference between:
ALTERNATIVE_2(oldinst, newinst1, flag1, newinst2, flag2)
and
ALTERNATIVE(ALTERNATIVE(oldinst, newinst1, flag1),
newinst2, flag2)
is that the outer alternative can add additional padding when the inner
alternative is the shorter one, which then results in
alt_instr::instrlen being inconsistent.
However, this is easily remedied since the alt_instr entries will be
consecutive and it is trivial to compute the max(alt_instr::instrlen) at
runtime while patching.
Specifically, after this the ALTERNATIVE_2 macro, after CPP expansion
(and manual layout), looks like this:
.macro ALTERNATIVE_2 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2
740:
740: \oldinstr ;
741: .skip -(((744f-743f)-(741b-740b)) > 0) * ((744f-743f)-(741b-740b)),0x90 ;
742: .pushsection .altinstructions,"a" ;
altinstr_entry 740b,743f,\ft_flags1,742b-740b,744f-743f ;
.popsection ;
.pushsection .altinstr_replacement,"ax" ;
743: \newinstr1 ;
744: .popsection ; ;
741: .skip -(((744f-743f)-(741b-740b)) > 0) * ((744f-743f)-(741b-740b)),0x90 ;
742: .pushsection .altinstructions,"a" ;
altinstr_entry 740b,743f,\ft_flags2,742b-740b,744f-743f ;
.popsection ;
.pushsection .altinstr_replacement,"ax" ;
743: \newinstr2 ;
744: .popsection ;
.endm
The only label that is ambiguous is 740, however they all reference the
same spot, so that doesn't matter.
NOTE: obviously only @oldinstr may be an alternative; making @newinstr
an alternative would mean patching .altinstr_replacement which very
likely isn't what is intended, also the labels will be confused in that
case.
[ bp: Debug an issue where it would match the wrong two insns and
and consider them nested due to the same signed offsets in the
.alternative section and use instr_va() to compare the full virtual
addresses instead.
- Use new labels to denote that the new, nested
alternatives are being used when staring at preprocessed output.
- Use the %c constraint everywhere instead of %P and document the
difference for future reference. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230628104952.GA2439977@hirez.programming.kicks-ass.net
|
|
When compiling the v6.9-rc1 kernel with the x32 compiler, the following
errors are reported. The reason is that we take an "unsigned long"
variable and print it using "PRIx64" format string.
In file included from check.c:16:
check.c: In function ‘add_dead_ends’:
/usr/src/git/linux-2.6/tools/objtool/include/objtool/warn.h:46:17: error: format ‘%llx’ expects argument of type ‘long long unsigned int’, but argument 5 has type ‘long unsigned int’ [-Werror=format=]
46 | "%s: warning: objtool: " format "\n", \
| ^~~~~~~~~~~~~~~~~~~~~~~~
check.c:613:33: note: in expansion of macro ‘WARN’
613 | WARN("can't find unreachable insn at %s+0x%" PRIx64,
| ^~~~
...
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: linux-kernel@vger.kernel.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
Pull LoongArch updates from Huacai Chen:
- Add objtool support for LoongArch
- Add ORC stack unwinder support for LoongArch
- Add kernel livepatching support for LoongArch
- Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig
- Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig
- Some bug fixes and other small changes
* tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
LoongArch/crypto: Clean up useless assignment operations
LoongArch: Define the __io_aw() hook as mmiowb()
LoongArch: Remove superfluous flush_dcache_page() definition
LoongArch: Move {dmw,tlb}_virt_to_page() definition to page.h
LoongArch: Change __my_cpu_offset definition to avoid mis-optimization
LoongArch: Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig
LoongArch: Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig
LoongArch: Add kernel livepatching support
LoongArch: Add ORC stack unwinder support
objtool: Check local label in read_unwind_hints()
objtool: Check local label in add_dead_ends()
objtool/LoongArch: Enable orc to be built
objtool/x86: Separate arch-specific and generic parts
objtool/LoongArch: Implement instruction decoder
objtool/LoongArch: Enable objtool to be built
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min
heap optimizations".
- Kuan-Wei Chiu has also sped up the library sorting code in the series
"lib/sort: Optimize the number of swaps and comparisons".
- Alexey Gladkov has added the ability for code running within an IPC
namespace to alter its IPC and MQ limits. The series is "Allow to
change ipc/mq sysctls inside ipc namespace".
- Geert Uytterhoeven has contributed some dhrystone maintenance work in
the series "lib: dhry: miscellaneous cleanups".
- Ryusuke Konishi continues nilfs2 maintenance work in the series
"nilfs2: eliminate kmap and kmap_atomic calls"
"nilfs2: fix kernel bug at submit_bh_wbc()"
- Nathan Chancellor has updated our build tools requirements in the
series "Bump the minimum supported version of LLVM to 13.0.1".
- Muhammad Usama Anjum continues with the selftests maintenance work in
the series "selftests/mm: Improve run_vmtests.sh".
- Oleg Nesterov has done some maintenance work against the signal code
in the series "get_signal: minor cleanups and fix".
Plus the usual shower of singleton patches in various parts of the tree.
Please see the individual changelogs for details.
* tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
nilfs2: prevent kernel bug at submit_bh_wbc()
nilfs2: fix failure to detect DAT corruption in btree and direct mappings
ocfs2: enable ocfs2_listxattr for special files
ocfs2: remove SLAB_MEM_SPREAD flag usage
assoc_array: fix the return value in assoc_array_insert_mid_shortcut()
buildid: use kmap_local_page()
watchdog/core: remove sysctl handlers from public header
nilfs2: use div64_ul() instead of do_div()
mul_u64_u64_div_u64: increase precision by conditionally swapping a and b
kexec: copy only happens before uchunk goes to zero
get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task
get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
get_signal: don't abuse ksig->info.si_signo and ksig->sig
const_structs.checkpatch: add device_type
Normalise "name (ad@dr)" MODULE_AUTHORs to "name <ad@dr>"
dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace()
list: leverage list_is_head() for list_entry_is_head()
nilfs2: MAINTAINERS: drop unreachable project mirror site
smp: make __smp_processor_id() 0-argument macro
fat: fix uninitialized field in nostale filehandles
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
"As is pretty normal for this tree, there are changes all over the
place, especially for small fixes, selftest improvements, and improved
macro usability.
Some header changes ended up landing via this tree as they depended on
the string header cleanups. Also, a notable set of changes is the work
for the reintroduction of the UBSAN signed integer overflow sanitizer
so that we can continue to make improvements on the compiler side to
make this sanitizer a more viable future security hardening option.
Summary:
- string.h and related header cleanups (Tanzir Hasan, Andy
Shevchenko)
- VMCI memcpy() usage and struct_size() cleanups (Vasiliy Kovalev,
Harshit Mogalapalli)
- selftests/powerpc: Fix load_unaligned_zeropad build failure
(Michael Ellerman)
- hardened Kconfig fragment updates (Marco Elver, Lukas Bulwahn)
- Handle tail call optimization better in LKDTM (Douglas Anderson)
- Use long form types in overflow.h (Andy Shevchenko)
- Add flags param to string_get_size() (Andy Shevchenko)
- Add Coccinelle script for potential struct_size() use (Jacob
Keller)
- Fix objtool corner case under KCFI (Josh Poimboeuf)
- Drop 13 year old backward compat CAP_SYS_ADMIN check (Jingzi Meng)
- Add str_plural() helper (Michal Wajdeczko, Kees Cook)
- Ignore relocations in .notes section
- Add comments to explain how __is_constexpr() works
- Fix m68k stack alignment expectations in stackinit Kunit test
- Convert string selftests to KUnit
- Add KUnit tests for fortified string functions
- Improve reporting during fortified string warnings
- Allow non-type arg to type_max() and type_min()
- Allow strscpy() to be called with only 2 arguments
- Add binary mode to leaking_addresses scanner
- Various small cleanups to leaking_addresses scanner
- Adding wrapping_*() arithmetic helper
- Annotate initial signed integer wrap-around in refcount_t
- Add explicit UBSAN section to MAINTAINERS
- Fix UBSAN self-test warnings
- Simplify UBSAN build via removal of CONFIG_UBSAN_SANITIZE_ALL
- Reintroduce UBSAN's signed overflow sanitizer"
* tag 'hardening-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (51 commits)
selftests/powerpc: Fix load_unaligned_zeropad build failure
string: Convert helpers selftest to KUnit
string: Convert selftest to KUnit
sh: Fix build with CONFIG_UBSAN=y
compiler.h: Explain how __is_constexpr() works
overflow: Allow non-type arg to type_max() and type_min()
VMCI: Fix possible memcpy() run-time warning in vmci_datagram_invoke_guest_handler()
lib/string_helpers: Add flags param to string_get_size()
x86, relocs: Ignore relocations in .notes section
objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks
overflow: Use POD in check_shl_overflow()
lib: stackinit: Adjust target string to 8 bytes for m68k
sparc: vdso: Disable UBSAN instrumentation
kernel.h: Move lib/cmdline.c prototypes to string.h
leaking_addresses: Provide mechanism to scan binary files
leaking_addresses: Ignore input device status lines
leaking_addresses: Use File::Temp for /tmp files
MAINTAINERS: Update LEAKING_ADDRESSES details
fortify: Improve buffer overflow reporting
fortify: Add KUnit tests for runtime overflows
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
- The biggest change is the rework of the percpu code, to support the
'Named Address Spaces' GCC feature, by Uros Bizjak:
- This allows C code to access GS and FS segment relative memory
via variables declared with such attributes, which allows the
compiler to better optimize those accesses than the previous
inline assembly code.
- The series also includes a number of micro-optimizations for
various percpu access methods, plus a number of cleanups of %gs
accesses in assembly code.
- These changes have been exposed to linux-next testing for the
last ~5 months, with no known regressions in this area.
- Fix/clean up __switch_to()'s broken but accidentally working handling
of FPU switching - which also generates better code
- Propagate more RIP-relative addressing in assembly code, to generate
slightly better code
- Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
make it easier for distros to follow & maintain these options
- Rework the x86 idle code to cure RCU violations and to clean up the
logic
- Clean up the vDSO Makefile logic
- Misc cleanups and fixes
* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
x86/idle: Select idle routine only once
x86/idle: Let prefer_mwait_c1_over_halt() return bool
x86/idle: Cleanup idle_setup()
x86/idle: Clean up idle selection
x86/idle: Sanitize X86_BUG_AMD_E400 handling
sched/idle: Conditionally handle tick broadcast in default_idle_call()
x86: Increase brk randomness entropy for 64-bit systems
x86/vdso: Move vDSO to mmap region
x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
x86/retpoline: Ensure default return thunk isn't used at runtime
x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
x86/vdso: Use $(addprefix ) instead of $(foreach )
x86/vdso: Simplify obj-y addition
x86/vdso: Consolidate targets and clean-files
x86/bugs: Rename CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK
x86/bugs: Rename CONFIG_CPU_SRSO => CONFIG_MITIGATION_SRSO
x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY => CONFIG_MITIGATION_IBRS_ENTRY
x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRY
x86/bugs: Rename CONFIG_SLS => CONFIG_MITIGATION_SLS
...
|
|
When update the latest upstream gcc and binutils, it generates some
objtool warnings on LoongArch, like this:
arch/loongarch/kernel/entry.o: warning: objtool: ret_from_fork+0x0: unreachable instruction
We can see that the reloc sym name is local label instead of section
in relocation section '.rela.discard.unwind_hints', in this case, the
reloc sym type is STT_NOTYPE instead of STT_SECTION. Let us check it
to not return -1, then use reloc->sym->offset instead of reloc addend
which is 0 to find the corresponding instruction.
Here are some detailed info:
[fedora@linux 6.8.test]$ gcc --version
gcc (GCC) 14.0.1 20240129 (experimental)
[fedora@linux 6.8.test]$ as --version
GNU assembler (GNU Binutils) 2.42.50.20240129
[fedora@linux 6.8.test]$ readelf -r arch/loongarch/kernel/entry.o | grep -A 3 "rela.discard.unwind_hints"
Relocation section '.rela.discard.unwind_hints' at offset 0x3a8 contains 7 entries:
Offset Info Type Sym. Value Sym. Name + Addend
000000000000 000a00000063 R_LARCH_32_PCREL 0000000000000000 .Lhere_1 + 0
00000000000c 000b00000063 R_LARCH_32_PCREL 00000000000000a8 .Lhere_50 + 0
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
When update the latest upstream gcc and binutils, it generates more
objtool warnings on LoongArch, like this:
init/main.o: warning: objtool: unexpected relocation symbol type in .rela.discard.unreachable
We can see that the reloc sym name is local label instead of section in
relocation section '.rela.discard.unreachable', in this case, the reloc
sym type is STT_NOTYPE instead of STT_SECTION.
As suggested by Peter Zijlstra, we add a "local_label" member in struct
symbol, then set it as true if symbol type is STT_NOTYPE and symbol name
starts with ".L" string in classify_symbols().
Let's check reloc->sym->local_label to not return -1 in add_dead_ends(),
and also use reloc->sym->offset instead of reloc addend which is 0 to
find the corresponding instruction. At the same time, let's replace the
variable "addend" with "offset" to reflect the reality.
Here are some detailed info:
[fedora@linux 6.8.test]$ gcc --version
gcc (GCC) 14.0.1 20240129 (experimental)
[fedora@linux 6.8.test]$ as --version
GNU assembler (GNU Binutils) 2.42.50.20240129
[fedora@linux 6.8.test]$ readelf -r init/main.o | grep -A 2 "rela.discard.unreachable"
Relocation section '.rela.discard.unreachable' at offset 0x6028 contains 1 entry:
Offset Info Type Sym. Value Sym. Name + Addend
000000000000 00d900000063 R_LARCH_32_PCREL 00000000000002c4 .L500^B1 + 0
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
Implement arch-specific init_orc_entry(), write_orc_entry(), reg_name(),
orc_type_name(), print_reg() and orc_print_dump(), then set BUILD_ORC as
y to build the orc related files.
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
Move init_orc_entry(), write_orc_entry(), reg_name(), orc_type_name()
and print_reg() from generic orc_gen.c and orc_dump.c to arch-specific
orc.c, then introduce a new function orc_print_dump() to print info.
This is preparation for later patch, no functionality change.
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
Only copy the minimal definitions of instruction opcodes and formats
in inst.h from arch/loongarch to tools/arch/loongarch, and also copy
the definition of sign_extend64() to tools/include/linux/bitops.h to
decode the following kinds of instructions:
(1) stack pointer related instructions
addi.d, ld.d, st.d, ldptr.d and stptr.d
(2) branch and jump related instructions
beq, bne, blt, bge, bltu, bgeu, beqz, bnez, bceqz, bcnez, b, bl and jirl
(3) other instructions
break, nop and ertn
See more info about instructions in LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
Add the minimal changes to enable objtool build on LoongArch,
most of the functions are stubs to only fix the build errors
when make -C tools/objtool.
This is similar with commit e52ec98c5ab1 ("objtool/powerpc:
Enable objtool to be built on ppc").
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
|
|
If SAVE and RESTORE unwind hints are in different basic blocks, and
objtool sees the RESTORE before the SAVE, it errors out with:
vmlinux.o: warning: objtool: vmw_port_hb_in+0x242: objtool isn't smart enough to handle this CFI save/restore combo
In such a case, defer following the RESTORE block until the
straight-line path gets followed later.
Fixes: 8faea26e6111 ("objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402240702.zJFNmahW-lkp@intel.com/
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20240227073527.avcm5naavbv3cj5s@treble
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
In preparation for KUnit testing and further improvements in fortify
failure reporting, split out the report and encode the function and access
failure (read or write overflow) into a single u8 argument. This mainly
ends up saving a tiny bit of space in the data segment. For a defconfig
with FORTIFY_SOURCE enabled:
$ size gcc/vmlinux.before gcc/vmlinux.after
text data bss dec hex filename
26132309 9760658 2195460 38088427 2452eeb gcc/vmlinux.before
26132386 9748382 2195460 38076228 244ff44 gcc/vmlinux.after
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
Since commit 3570ee046c46b5dc ("s390/smp: keep the original lowcore for
CPU 0"), there is no longer any architecture that needs to override
arch_call_rest_init().
Remove the weak wrapper around rest_init(), call rest_init() directly, and
make rest_init() static.
Link: https://lkml.kernel.org/r/aa10868bfb176eef4abb8bb4a710b85330792694.1706106183.git.geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Update the objtool decoder to know about the ERET[US] instructions
(type INSN_CONTEXT_SWITCH).
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-11-xin3.li@intel.com
|
|
Step 10/10 of the namespace unification of CPU mitigations related Kconfig options.
[ mingo: Added one more case. ]
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-11-leitao@debian.org
|
|
Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.
[ mingo: Converted a few more uses in comments/messages as well. ]
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ariel Miculas <amiculas@cisco.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixlet from Ingo Molnar:
"Address a GCC-14 warning: there's no real bug, but indeed the calloc
order doesn't match the prototype.
(Side note: we should really add zalloc() for such cases)"
* tag 'objtool-core-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix calloc call for new -Walloc-size
|
|
This code is rarely (never?) enabled by distros, and it hasn't caught
anything in decades. Let's kill off this legacy debug code.
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
GCC 14 introduces a new -Walloc-size included in -Wextra which errors out
like:
```
check.c: In function ‘cfi_alloc’:
check.c:294:33: error: allocation of insufficient size ‘1’ for type ‘struct cfi_state’ with size ‘320’ [-Werror=alloc-size]
294 | struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
| ^~~~~~
```
The calloc prototype is:
```
void *calloc(size_t nmemb, size_t size);
```
So, just swap the number of members and size arguments to match the prototype, as
we're initialising 1 struct of size `sizeof(struct ...)`. GCC then sees we're not
doing anything wrong.
Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20231107205504.1470006-1-sam@gentoo.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 TDX updates from Dave Hansen:
"The majority of this is a rework of the assembly and C wrappers that
are used to talk to the TDX module and VMM. This is a nice cleanup in
general but is also clearing the way for using this code when Linux is
the TDX VMM.
There are also some tidbits to make TDX guests play nicer with Hyper-V
and to take advantage the hardware TSC.
Summary:
- Refactor and clean up TDX hypercall/module call infrastructure
- Handle retrying/resuming page conversion hypercalls
- Make sure to use the (shockingly) reliable TSC in TDX guests"
[ TLA reminder: TDX is "Trust Domain Extensions", Intel's guest VM
confidentiality technology ]
* tag 'x86_tdx_for_6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tdx: Mark TSC reliable
x86/tdx: Fix __noreturn build warning around __tdx_hypercall_failed()
x86/virt/tdx: Make TDX_MODULE_CALL handle SEAMCALL #UD and #GP
x86/virt/tdx: Wire up basic SEAMCALL functions
x86/tdx: Remove 'struct tdx_hypercall_args'
x86/tdx: Reimplement __tdx_hypercall() using TDX_MODULE_CALL asm
x86/tdx: Make TDX_HYPERCALL asm similar to TDX_MODULE_CALL
x86/tdx: Extend TDX_MODULE_CALL to support more TDCALL/SEAMCALL leafs
x86/tdx: Pass TDCALL/SEAMCALL input/output registers via a structure
x86/tdx: Rename __tdx_module_call() to __tdcall()
x86/tdx: Make macros of TDCALLs consistent with the spec
x86/tdx: Skip saving output regs when SEAMCALL fails with VMFailInvalid
x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro
x86/tdx: Retry partially-completed page conversion hypercalls
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
"Misc fixes and cleanups:
- Fix potential MAX_NAME_LEN limit related build failures
- Fix scripts/faddr2line symbol filtering bug
- Fix scripts/faddr2line on LLVM=1
- Fix scripts/faddr2line to accept readelf output with mapping
symbols
- Minor cleanups"
* tag 'objtool-core-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
scripts/faddr2line: Skip over mapping symbols in output from readelf
scripts/faddr2line: Use LLVM addr2line and readelf if LLVM=1
scripts/faddr2line: Don't filter out non-function symbols from readelf
objtool: Remove max symbol name length limitation
objtool: Propagate early errors
objtool: Use 'the fallthrough' pseudo-keyword
x86/speculation, objtool: Use absolute relocations for annotations
x86/unwind/orc: Remove redundant initialization of 'mid' pointer in __orc_find()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 hw mitigation updates from Borislav Petkov:
- A bunch of improvements, cleanups and fixlets to the SRSO mitigation
machinery and other, general cleanups to the hw mitigations code, by
Josh Poimboeuf
- Improve the return thunk detection by objtool as it is absolutely
important that the default return thunk is not used after returns
have been patched. Future work to detect and report this better is
pending
- Other misc cleanups and fixes
* tag 'x86_bugs_for_6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/retpoline: Document some thunk handling aspects
x86/retpoline: Make sure there are no unconverted return thunks due to KCSAN
x86/callthunks: Delete unused "struct thunk_desc"
x86/vdso: Run objtool on vdso32-setup.o
objtool: Fix return thunk patching in retpolines
x86/srso: Remove unnecessary semicolon
x86/pti: Fix kernel warnings for pti= and nopti cmdline options
x86/calldepth: Rename __x86_return_skl() to call_depth_return_thunk()
x86/nospec: Refactor UNTRAIN_RET[_*]
x86/rethunk: Use SYM_CODE_START[_LOCAL]_NOALIGN macros
x86/srso: Disentangle rethunk-dependent options
x86/srso: Move retbleed IBPB check into existing 'has_microcode' code block
x86/bugs: Remove default case for fully switched enums
x86/srso: Remove 'pred_cmd' label
x86/srso: Unexport untraining functions
x86/srso: Improve i-cache locality for alias mitigation
x86/srso: Fix unret validation dependencies
x86/srso: Fix vulnerability reporting for missing microcode
x86/srso: Print mitigation for retbleed IBPB case
x86/srso: Print actual mitigation if requested mitigation isn't possible
...
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Pull initial bcachefs updates from Kent Overstreet:
"Here's the bcachefs filesystem pull request.
One new patch since last week: the exportfs constants ended up
conflicting with other filesystems that are also getting added to the
global enum, so switched to new constants picked by Amir.
The only new non fs/bcachefs/ patch is the objtool patch that adds
bcachefs functions to the list of noreturns. The patch that exports
osq_lock() has been dropped for now, per Ingo"
* tag 'bcachefs-2023-10-30' of https://evilpiepirate.org/git/bcachefs: (2781 commits)
exportfs: Change bcachefs fid_type enum to avoid conflicts
bcachefs: Refactor memcpy into direct assignment
bcachefs: Fix drop_alloc_keys()
bcachefs: snapshot_create_lock
bcachefs: Fix snapshot skiplists during snapshot deletion
bcachefs: bch2_sb_field_get() refactoring
bcachefs: KEY_TYPE_error now counts towards i_sectors
bcachefs: Fix handling of unknown bkey types
bcachefs: Switch to unsafe_memcpy() in a few places
bcachefs: Use struct_size()
bcachefs: Correctly initialize new buckets on device resize
bcachefs: Fix another smatch complaint
bcachefs: Use strsep() in split_devs()
bcachefs: Add iops fields to bch_member
bcachefs: Rename bch_sb_field_members -> bch_sb_field_members_v1
bcachefs: New superblock section members_v2
bcachefs: Add new helper to retrieve bch_member from sb
bcachefs: bucket_lock() is now a sleepable lock
bcachefs: fix crc32c checksum merge byte order problem
bcachefs: Fix bch2_inode_delete_keys()
...
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With CONFIG_RETHUNK enabled, the compiler replaces every RET with a tail
call to a return thunk ('JMP __x86_return_thunk'). Objtool annotates
all such return sites so they can be patched during boot by
apply_returns().
The implementation of __x86_return_thunk() is just a bare RET. It's
only meant to be used temporarily until apply_returns() patches all
return sites with either a JMP to another return thunk or an actual RET.
Removing the .text..__x86.return_thunk section would break objtool's
detection of return sites in retpolines. Since retpolines and return
thunks would land in the same section, the compiler no longer uses
relocations for the intra-section jumps between the retpolines and the
return thunk, causing objtool to overlook them.
As a result, none of the retpolines' return sites would get patched.
Each one stays at 'JMP __x86_return_thunk', effectively a bare RET.
Fix it by teaching objtool to detect when a non-relocated jump target is
a return thunk (or retpoline).
[ bp: Massage the commit message now that the offending commit
removing the .text..__x86.return_thunk section has been zapped.
Still keep the objtool change here as it makes objtool more robust
wrt handling such intra-TU jumps without relocations, should some
toolchain and/or config generate them in the future. ]
Reported-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231012024737.eg5phclogp67ik6x@treble
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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If one of the symbols processed by read_symbols() happens to have a
.cold variant with a name longer than objtool's MAX_NAME_LEN limit, the
build fails.
Avoid this problem by just using strndup() to copy the parent function's
name, rather than strncpy()ing it onto the stack.
Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Link: https://lore.kernel.org/r/41e94cfea1d9131b758dd637fecdeacd459d4584.1696355111.git.aplattner@nvidia.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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If objtool runs into a problem that causes it to exit early, the overall
tool still returns a status code of 0, which causes the build to
continue as if nothing went wrong.
Note this only affects early errors, as later errors are still ignored
by check().
Fixes: b51277eb9775 ("objtool: Ditch subcommands")
Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Link: https://lore.kernel.org/r/cb6a28832d24b2ebfafd26da9abb95f874c83045.1696355111.git.aplattner@nvidia.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Replace the existing /* fallthrough */ comments with the
new 'fallthrough' pseudo-keyword macro:
https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
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LKP reported below build warning:
vmlinux.o: warning: objtool: __tdx_hypercall+0x128: __tdx_hypercall_failed() is missing a __noreturn annotation
The __tdx_hypercall_failed() function definition already has __noreturn
annotation, but it turns out the __noreturn must be annotated to the
function declaration.
PeterZ explains:
"FWIW, the reason being that...
The point of noreturn is that the caller should know to stop generating
code. For that the declaration needs the attribute, because call sites
typically do not have access to the function definition in C."
Add __noreturn annotation to the declaration of __tdx_hypercall_failed()
to fix. It's not a bad idea to document the __noreturn nature at the
definition site either, so keep the annotation at the definition.
Note <asm/shared/tdx.h> is also included by TDX related assembly files.
Include <linux/compiler_attributes.h> only in case of !__ASSEMBLY__
otherwise compiling assembly file would trigger build error.
Also, following the objtool documentation, add __tdx_hypercall_failed()
to "tools/objtool/noreturns.h".
Fixes: c641cfb5c157 ("x86/tdx: Make TDX_HYPERCALL asm similar to TDX_MODULE_CALL")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230918041858.331234-1-kai.huang@intel.com
Closes: https://lore.kernel.org/oe-kbuild-all/202309140828.9RdmlH2Z-lkp@intel.com/
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Cold functions and their non-cold counterparts can use _THIS_IP_ to
reference each other. Don't warn about !ENDBR in that case.
Note that for GCC this is currently irrelevant in light of the following
commit
c27cd083cfb9 ("Compiler attributes: GCC cold function alignment workarounds")
which disabled cold functions in the kernel. However this may still be
possible with Clang.
Fixes several warnings like the following:
drivers/scsi/bnx2i/bnx2i.prelink.o: warning: objtool: bnx2i_hw_ep_disconnect+0x19d: relocation to !ENDBR: bnx2i_hw_ep_disconnect.cold+0x0
drivers/net/ipvlan/ipvlan.prelink.o: warning: objtool: ipvlan_addr4_event.cold+0x28: relocation to !ENDBR: ipvlan_addr4_event+0xda
drivers/net/ipvlan/ipvlan.prelink.o: warning: objtool: ipvlan_addr6_event.cold+0x26: relocation to !ENDBR: ipvlan_addr6_event+0xb7
drivers/net/ethernet/broadcom/tg3.prelink.o: warning: objtool: tg3_set_ringparam.cold+0x17: relocation to !ENDBR: tg3_set_ringparam+0x115
drivers/net/ethernet/broadcom/tg3.prelink.o: warning: objtool: tg3_self_test.cold+0x17: relocation to !ENDBR: tg3_self_test+0x2e1
drivers/target/iscsi/cxgbit/cxgbit.prelink.o: warning: objtool: __cxgbit_free_conn.cold+0x24: relocation to !ENDBR: __cxgbit_free_conn+0xfb
net/can/can.prelink.o: warning: objtool: can_rx_unregister.cold+0x2c: relocation to !ENDBR: can_rx_unregister+0x11b
drivers/net/ethernet/qlogic/qed/qed.prelink.o: warning: objtool: qed_spq_post+0xc0: relocation to !ENDBR: qed_spq_post.cold+0x9a
drivers/net/ethernet/qlogic/qed/qed.prelink.o: warning: objtool: qed_iwarp_ll2_comp_syn_pkt.cold+0x12f: relocation to !ENDBR: qed_iwarp_ll2_comp_syn_pkt+0x34b
net/tipc/tipc.prelink.o: warning: objtool: tipc_nametbl_publish.cold+0x21: relocation to !ENDBR: tipc_nametbl_publish+0xa6
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/d8f1ab6a23a6105bc023c132b105f245c7976be6.1694476559.git.jpoimboe@kernel.org
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For stack-validation of a frame-pointer build, objtool validates that
every CALL instruction is preceded by a frame-setup. The new SRSO
return thunks violate this with their RSB stuffing trickery.
Extend the __fentry__ exception to also cover the embedded_insn case
used for this. This cures:
vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup
Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-ass.net
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Rename the original retbleed return thunk and untrain_ret to
retbleed_return_thunk() and retbleed_untrain_ret().
No functional changes.
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230814121148.909378169@infradead.org
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Use the existing configurable return thunk. There is absolute no
justification for having created this __x86_return_thunk alternative.
To clarify, the whole thing looks like:
Zen3/4 does:
srso_alias_untrain_ret:
nop2
lfence
jmp srso_alias_return_thunk
int3
srso_alias_safe_ret: // aliasses srso_alias_untrain_ret just so
add $8, %rsp
ret
int3
srso_alias_return_thunk:
call srso_alias_safe_ret
ud2
While Zen1/2 does:
srso_untrain_ret:
movabs $foo, %rax
lfence
call srso_safe_ret (jmp srso_return_thunk ?)
int3
srso_safe_ret: // embedded in movabs instruction
add $8,%rsp
ret
int3
srso_return_thunk:
call srso_safe_ret
ud2
While retbleed does:
zen_untrain_ret:
test $0xcc, %bl
lfence
jmp zen_return_thunk
int3
zen_return_thunk: // embedded in the test instruction
ret
int3
Where Zen1/2 flush the BTB entry using the instruction decoder trick
(test,movabs) Zen3/4 use BTB aliasing. SRSO adds a return sequence
(srso_safe_ret()) which forces the function return instruction to
speculate into a trap (UD2). This RET will then mispredict and
execution will continue at the return site read from the top of the
stack.
Pick one of three options at boot (evey function can only ever return
once).
[ bp: Fixup commit message uarch details and add them in a comment in
the code too. Add a comment about the srso_select_mitigation()
dependency on retbleed_select_mitigation(). Add moar ifdeffery for
32-bit builds. Add a dummy srso_untrain_ret_alias() definition for
32-bit alternatives needing the symbol. ]
Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230814121148.842775684@infradead.org
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Objtool --rethunk does two things:
- it collects all (tail) call's of __x86_return_thunk and places them
into .return_sites. These are typically compiler generated, but
RET also emits this same.
- it fudges the validation of the __x86_return_thunk symbol; because
this symbol is inside another instruction, it can't actually find
the instruction pointed to by the symbol offset and gets upset.
Because these two things pertained to the same symbol, there was no
pressing need to separate these two separate things.
However, alas, along comes SRSO and more crazy things to deal with
appeared.
The SRSO patch itself added the following symbol names to identify as
rethunk:
'srso_untrain_ret', 'srso_safe_ret' and '__ret'
Where '__ret' is the old retbleed return thunk, 'srso_safe_ret' is a
new similarly embedded return thunk, and 'srso_untrain_ret' is
completely unrelated to anything the above does (and was only included
because of that INT3 vs UD2 issue fixed previous).
Clear things up by adding a second category for the embedded instruction
thing.
Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230814121148.704502245@infradead.org
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The linker script arch/x86/kernel/vmlinux.lds.S matches the thunk
sections ".text.__x86.*" from arch/x86/lib/retpoline.S as follows:
.text {
[...]
TEXT_TEXT
[...]
__indirect_thunk_start = .;
*(.text.__x86.*)
__indirect_thunk_end = .;
[...]
}
Macro TEXT_TEXT references TEXT_MAIN which normally expands to only
".text". However, with CONFIG_LTO_CLANG, TEXT_MAIN becomes
".text .text.[0-9a-zA-Z_]*" which wrongly matches also the thunk
sections. The output layout is then different than expected. For
instance, the currently defined range [__indirect_thunk_start,
__indirect_thunk_end] becomes empty.
Prevent the problem by using ".." as the first separator, for example,
".text..__x86.indirect_thunk". This pattern is utilized by other
explicit section names which start with one of the standard prefixes,
such as ".text" or ".data", and that need to be individually selected in
the linker script.
[ nathan: Fix conflicts with SRSO and fold in fix issue brought up by
Andrew Cooper in post-review:
https://lore.kernel.org/20230803230323.1478869-1-andrew.cooper3@citrix.com ]
Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230711091952.27944-2-petr.pavlu@suse.com
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Add a mitigation for the speculative return address stack overflow
vulnerability found on AMD processors.
The mitigation works by ensuring all RET instructions speculate to
a controlled location, similar to how speculation is controlled in the
retpoline sequence. To accomplish this, the __x86_return_thunk forces
the CPU to mispredict every function return using a 'safe return'
sequence.
To ensure the safety of this mitigation, the kernel must ensure that the
safe return sequence is itself free from attacker interference. In Zen3
and Zen4, this is accomplished by creating a BTB alias between the
untraining function srso_untrain_ret_alias() and the safe return
function srso_safe_ret_alias() which results in evicting a potentially
poisoned BTB entry and using that safe one for all function returns.
In older Zen1 and Zen2, this is accomplished using a reinterpretation
technique similar to Retbleed one: srso_untrain_ret() and
srso_safe_ret().
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
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Function elf_open_read() only zero initializes the initial part of
allocated struct elf; num_relocs member was recently added outside the
zeroed part so that it was left uninitialized, resulting in build failures
on some systems.
The partial initialization is a relic of times when struct elf had large
hash tables embedded. This is no longer the case so remove the trap and
initialize the whole structure instead.
Fixes: eb0481bbc4ce ("objtool: Fix reloc_hash size")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20230629102051.42E8360467@lion.mk-sys.cz
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