- Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
additional flags to be passed to user-space programs.
- Fix missing fflush() bugs in Kconfig and fixdep
- Fix a minor bug in the comment format of the .config file
- Make kallsyms ignore llvm's local labels, .L*
- Fix UAPI compile-test for cross-compiling with Clang
- Extend the LLVM= syntax to support LLVM=<suffix> form for using a
particular version of LLVm, and LLVM=<prefix> form for using custom
LLVM in a particular directory path.
- Clean up Makefiles
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Merge tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
additional flags to be passed to user-space programs.
- Fix missing fflush() bugs in Kconfig and fixdep
- Fix a minor bug in the comment format of the .config file
- Make kallsyms ignore llvm's local labels, .L*
- Fix UAPI compile-test for cross-compiling with Clang
- Extend the LLVM= syntax to support LLVM=<suffix> form for using a
particular version of LLVm, and LLVM=<prefix> form for using custom
LLVM in a particular directory path.
- Clean up Makefiles
* tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: Make $(LLVM) more flexible
kbuild: add --target to correctly cross-compile UAPI headers with Clang
fixdep: use fflush() and ferror() to ensure successful write to files
arch: syscalls: simplify uapi/kapi directory creation
usr/include: replace extra-y with always-y
certs: simplify empty certs creation in certs/Makefile
certs: include certs/signing_key.x509 unconditionally
kallsyms: ignore all local labels prefixed by '.L'
kconfig: fix missing '# end of' for empty menu
kconfig: add fflush() before ferror() check
kbuild: replace $(if A,A,B) with $(or A,B)
kbuild: Add environment variables for userprogs flags
kbuild: unify cmd_copy and cmd_shipped
$(shell ...) expands to empty. There is no need to assign it to _dummy.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Commit 0bf6276392 ("x32: Warn and disable rather than error if
binutils too old") added a small test in arch/x86/Makefile because
binutils 2.22 or newer is needed to properly support elf32-x86-64. This
check is no longer necessary, as the minimum supported version of
binutils is 2.23, which is enforced at configuration time with
scripts/min-tool-version.sh.
Remove this check and replace all uses of CONFIG_X86_X32 with
CONFIG_X86_X32_ABI, as two symbols are no longer necessary.
[nathan: Rebase, fix up a few places where CONFIG_X86_X32 was still
used, and simplify commit message to satisfy -tip requirements]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220314194842.3452-2-nathan@kernel.org
Annotate away some of the generic code references. This is things
where we take the address of a symbol for exception handling or return
addresses (eg. context switch).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.877758523@infradead.org
Kernel entry points should be having ENDBR on for IBT configs.
The SYSCALL entry points are found through taking their respective
address in order to program them in the MSRs, while the exception
entry points are found through UNWIND_HINT_IRET_REGS.
The rule is that any UNWIND_HINT_IRET_REGS at sym+0 should have an
ENDBR, see the later objtool ibt validation patch.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.933157479@infradead.org
Even though Xen currently doesn't advertise IBT, prepare for when it
will eventually do so and sprinkle the ENDBR dust accordingly.
Even though most of the entry points are IRET like, the CPL0
Hypervisor can set WAIT-FOR-ENDBR and demand ENDBR at these sites.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.873919996@infradead.org
By doing an early rewrite of 'jmp native_iret` in
restore_regs_and_return_to_kernel() we can get rid of the last
INTERRUPT_RETURN user and paravirt_iret.
Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.815039833@infradead.org
Since commit 5c8f6a2e31 ("x86/xen: Add
xenpv_restore_regs_and_return_to_usermode()") Xen will no longer reach
this code and we can do away with the paravirt
SWAPGS/INTERRUPT_RETURN.
Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.756014488@infradead.org
Pull signal/exit/ptrace updates from Eric Biederman:
"This set of changes deletes some dead code, makes a lot of cleanups
which hopefully make the code easier to follow, and fixes bugs found
along the way.
The end-game which I have not yet reached yet is for fatal signals
that generate coredumps to be short-circuit deliverable from
complete_signal, for force_siginfo_to_task not to require changing
userspace configured signal delivery state, and for the ptrace stops
to always happen in locations where we can guarantee on all
architectures that the all of the registers are saved and available on
the stack.
Removal of profile_task_ext, profile_munmap, and profile_handoff_task
are the big successes for dead code removal this round.
A bunch of small bug fixes are included, as most of the issues
reported were small enough that they would not affect bisection so I
simply added the fixes and did not fold the fixes into the changes
they were fixing.
There was a bug that broke coredumps piped to systemd-coredump. I
dropped the change that caused that bug and replaced it entirely with
something much more restrained. Unfortunately that required some
rebasing.
Some successes after this set of changes: There are few enough calls
to do_exit to audit in a reasonable amount of time. The lifetime of
struct kthread now matches the lifetime of struct task, and the
pointer to struct kthread is no longer stored in set_child_tid. The
flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
removed. Issues where task->exit_code was examined with
signal->group_exit_code should been examined were fixed.
There are several loosely related changes included because I am
cleaning up and if I don't include them they will probably get lost.
The original postings of these changes can be found at:
https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.orghttps://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.orghttps://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org
I trimmed back the last set of changes to only the obviously correct
once. Simply because there was less time for review than I had hoped"
* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
ptrace/m68k: Stop open coding ptrace_report_syscall
ptrace: Remove unused regs argument from ptrace_report_syscall
ptrace: Remove second setting of PT_SEIZED in ptrace_attach
taskstats: Cleanup the use of task->exit_code
exit: Use the correct exit_code in /proc/<pid>/stat
exit: Fix the exit_code for wait_task_zombie
exit: Coredumps reach do_group_exit
exit: Remove profile_handoff_task
exit: Remove profile_task_exit & profile_munmap
signal: clean up kernel-doc comments
signal: Remove the helper signal_group_exit
signal: Rename group_exit_task group_exec_task
coredump: Stop setting signal->group_exit_task
signal: Remove SIGNAL_GROUP_COREDUMP
signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
signal: Make coredump handling explicit in complete_signal
signal: Have prepare_signal detect coredumps using signal->core_state
signal: Have the oom killer detect coredumps using signal->core_state
exit: Move force_uaccess back into do_exit
exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
...
Merge misc updates from Andrew Morton:
"146 patches.
Subsystems affected by this patch series: kthread, ia64, scripts,
ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
damon)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
mm/damon: hide kernel pointer from tracepoint event
mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
mm/damon/dbgfs: remove an unnecessary variable
mm/damon: move the implementation of damon_insert_region to damon.h
mm/damon: add access checking for hugetlb pages
Docs/admin-guide/mm/damon/usage: update for schemes statistics
mm/damon/dbgfs: support all DAMOS stats
Docs/admin-guide/mm/damon/reclaim: document statistics parameters
mm/damon/reclaim: provide reclamation statistics
mm/damon/schemes: account how many times quota limit has exceeded
mm/damon/schemes: account scheme actions that successfully applied
mm/damon: remove a mistakenly added comment for a future feature
Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
Docs/admin-guide/mm/damon/usage: remove redundant information
Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
mm/damon: convert macro functions to static inline functions
mm/damon: modify damon_rand() macro to static inline function
mm/damon: move damon_rand() definition into damon.h
...
misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
LIVEPATCH as the backtrace misses the function which is being fixed up.
- Add Straight Light Speculation mitigation support which uses a new
compiler switch -mharden-sls= which sticks an INT3 after a RET or an
indirect branch in order to block speculation after them. Reportedly,
CPUs do speculate behind such insns.
- The usual set of cleanups and improvements
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Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov:
- Get rid of all the .fixup sections because this generates
misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
LIVEPATCH as the backtrace misses the function which is being fixed
up.
- Add Straight Line Speculation mitigation support which uses a new
compiler switch -mharden-sls= which sticks an INT3 after a RET or an
indirect branch in order to block speculation after them. Reportedly,
CPUs do speculate behind such insns.
- The usual set of cleanups and improvements
* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
x86/entry_32: Fix segment exceptions
objtool: Remove .fixup handling
x86: Remove .fixup section
x86/word-at-a-time: Remove .fixup usage
x86/usercopy: Remove .fixup usage
x86/usercopy_32: Simplify __copy_user_intel_nocache()
x86/sgx: Remove .fixup usage
x86/checksum_32: Remove .fixup usage
x86/vmx: Remove .fixup usage
x86/kvm: Remove .fixup usage
x86/segment: Remove .fixup usage
x86/fpu: Remove .fixup usage
x86/xen: Remove .fixup usage
x86/uaccess: Remove .fixup usage
x86/futex: Remove .fixup usage
x86/msr: Remove .fixup usage
x86/extable: Extend extable functionality
x86/entry_32: Remove .fixup usage
x86/entry_64: Remove .fixup usage
x86/copy_mc_64: Remove .fixup usage
...
The LKP robot reported that commit in Fixes: caused a failure. Turns out
the ldt_gdt_32 selftest turns into an infinite loop trying to clear the
segment.
As discovered by Sean, what happens is that PARANOID_EXIT_TO_KERNEL_MODE
in the handle_exception_return path overwrites the entry stack data with
the task stack data, restoring the "bad" segment value.
Instead of having the exception retry the instruction, have it emulate
the full instruction. Replace EX_TYPE_POP_ZERO with EX_TYPE_POP_REG
which will do the equivalent of: POP %reg; MOV $imm, %reg.
In order to encode the segment registers, add them as registers 8-11 for
32-bit.
By setting regs->[defg]s the (nested) RESTORE_REGS will pop this value
at the end of the exception handler and by increasing regs->sp, it will
have skipped the stack slot.
This was debugged by Sean Christopherson <seanjc@google.com>.
[ bp: Add EX_REG_GS too. ]
Fixes: aa93e2ad74 ("x86/entry_32: Remove .fixup usage")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/Yd1l0gInc4zRcnt/@hirez.programming.kicks-ass.net
The -nostdlib option requests the compiler to not use the standard
system startup files or libraries when linking. It is effective only
when $(CC) is used as a linker driver.
Since
379d98ddf4 ("x86: vdso: Use $LD instead of $CC to link")
$(LD) is directly used, hence -nostdlib is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20211107162641.324688-1-masahiroy@kernel.org
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Where possible, push the .fixup into code, at the tail of functions.
This is hard for macros since they're used in multiple functions,
therefore introduce a new extable handler to pop zeros.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101325.245184699@infradead.org
Place the anonymous .fixup code at the tail of the regular functions.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Link: https://lore.kernel.org/r/20211110101325.186049322@infradead.org
Replace all ret/retq instructions with RET in preparation of making
RET a macro. Since AS is case insensitive it's a big no-op without
RET defined.
find arch/x86/ -name \*.S | while read file
do
sed -i 's/\<ret[q]*\>/RET/' $file
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org
In the native case, PER_CPU_VAR(cpu_tss_rw + TSS_sp0) is the
trampoline stack. But XEN pv doesn't use trampoline stack, so
PER_CPU_VAR(cpu_tss_rw + TSS_sp0) is also the kernel stack.
In that case, source and destination stacks are identical, which means
that reusing swapgs_restore_regs_and_return_to_usermode() in XEN pv
would cause %rsp to move up to the top of the kernel stack and leave the
IRET frame below %rsp.
This is dangerous as it can be corrupted if #NMI / #MC hit as either of
these events occurring in the middle of the stack pushing would clobber
data on the (original) stack.
And, with XEN pv, swapgs_restore_regs_and_return_to_usermode() pushing
the IRET frame on to the original address is useless and error-prone
when there is any future attempt to modify the code.
[ bp: Massage commit message. ]
Fixes: 7f2590a110 ("x86/entry/64: Use a per-CPU trampoline stack for IDT entries")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lkml.kernel.org/r/20211126101209.8613-4-jiangshanlai@gmail.com
The commit
c758907004 ("x86/entry/64: Remove unneeded kernel CR3 switching")
removed a CR3 write in the faulting path of load_gs_index().
But the path's FENCE_SWAPGS_USER_ENTRY has no fence operation if PTI is
enabled, see spectre_v1_select_mitigation().
Rather, it depended on the serializing CR3 write of SWITCH_TO_KERNEL_CR3
and since it got removed, add a FENCE_SWAPGS_KERNEL_ENTRY call to make
sure speculation is blocked.
[ bp: Massage commit message and comment. ]
Fixes: c758907004 ("x86/entry/64: Remove unneeded kernel CR3 switching")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211126101209.8613-3-jiangshanlai@gmail.com
Commit
18ec54fdd6 ("x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations")
added FENCE_SWAPGS_{KERNEL|USER}_ENTRY for conditional SWAPGS. In
paranoid_entry(), it uses only FENCE_SWAPGS_KERNEL_ENTRY for both
branches. This is because the fence is required for both cases since the
CR3 write is conditional even when PTI is enabled.
But
96b2371413 ("x86/entry/64: Switch CR3 before SWAPGS in paranoid entry")
changed the order of SWAPGS and the CR3 write. And it missed the needed
FENCE_SWAPGS_KERNEL_ENTRY for the user gsbase case.
Add it back by changing the branches so that FENCE_SWAPGS_KERNEL_ENTRY
can cover both branches.
[ bp: Massage, fix typos, remove obsolete comment while at it. ]
Fixes: 96b2371413 ("x86/entry/64: Switch CR3 before SWAPGS in paranoid entry")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211126101209.8613-2-jiangshanlai@gmail.com
Recently to prevent issues with SECCOMP_RET_KILL and similar signals
being changed before they are delivered SA_IMMUTABLE was added.
Unfortunately this broke debuggers[1][2] which reasonably expect
to be able to trap synchronous SIGTRAP and SIGSEGV even when
the target process is not configured to handle those signals.
Add force_exit_sig and use it instead of force_fatal_sig where
historically the code has directly called do_exit. This has the
implementation benefits of going through the signal exit path
(including generating core dumps) without the danger of allowing
userspace to ignore or change these signals.
This avoids userspace regressions as older kernels exited with do_exit
which debuggers also can not intercept.
In the future is should be possible to improve the quality of
implementation of the kernel by changing some of these force_exit_sig
calls to force_fatal_sig. That can be done where it matters on
a case-by-case basis with careful analysis.
Reported-by: Kyle Huey <me@kylehuey.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
[1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
[2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020
Fixes: 00b06da29c ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Fixes: a3616a3c02 ("signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die")
Fixes: 83a1f27ad7 ("signal/powerpc: On swapcontext failure force SIGSEGV")
Fixes: 9bc508cf07 ("signal/s390: Use force_sigsegv in default_trap_handler")
Fixes: 086ec444f8 ("signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig")
Fixes: c317d306d5 ("signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails")
Fixes: 695dd0d634 ("signal/x86: In emulate_vsyscall force a signal instead of calling do_exit")
Fixes: 1fbd60df8a ("signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.")
Fixes: 941edc5bf1 ("exit/syscall_user_dispatch: Send ordinary signals on failure")
Link: https://lkml.kernel.org/r/871r3dqfv8.fsf_-_@email.froward.int.ebiederm.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull exit cleanups from Eric Biederman:
"While looking at some issues related to the exit path in the kernel I
found several instances where the code is not using the existing
abstractions properly.
This set of changes introduces force_fatal_sig a way of sending a
signal and not allowing it to be caught, and corrects the misuse of
the existing abstractions that I found.
A lot of the misuse of the existing abstractions are silly things such
as doing something after calling a no return function, rolling BUG by
hand, doing more work than necessary to terminate a kernel thread, or
calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL).
In the review a deficiency in force_fatal_sig and force_sig_seccomp
where ptrace or sigaction could prevent the delivery of the signal was
found. I have added a change that adds SA_IMMUTABLE to change that
makes it impossible to interrupt the delivery of those signals, and
allows backporting to fix force_sig_seccomp
And Arnd found an issue where a function passed to kthread_run had the
wrong prototype, and after my cleanup was failing to build."
* 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits)
soc: ti: fix wkup_m3_rproc_boot_thread return type
signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed
signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV)
exit/r8188eu: Replace the macro thread_exit with a simple return 0
exit/rtl8712: Replace the macro thread_exit with a simple return 0
exit/rtl8723bs: Replace the macro thread_exit with a simple return 0
signal/x86: In emulate_vsyscall force a signal instead of calling do_exit
signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig
signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails
exit/syscall_user_dispatch: Send ordinary signals on failure
signal: Implement force_fatal_sig
exit/kthread: Have kernel threads return instead of calling do_exit
signal/s390: Use force_sigsegv in default_trap_handler
signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.
signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON
signal/sparc: In setup_tsb_params convert open coded BUG into BUG
signal/powerpc: On swapcontext failure force SIGSEGV
signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL)
signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT
signal/sparc32: Remove unreachable do_exit in do_sparc_fault
...
Directly calling do_exit with a signal number has the problem that
all of the side effects of the signal don't happen, such as
killing all of the threads of a process instead of just the
calling thread.
So replace do_exit(SIGSYS) with force_fatal_sig(SIGSYS) which
causes the signal handling to take it's normal path and work
as expected.
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20211020174406.17889-17-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
These are all handled correctly when calling the native system call entry
point, so remove the special cases.
Link: https://lkml.kernel.org/r/20210727144859.4150043-6-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Add -s option (strict mode) to merge_config.sh to make it fail when
any symbol is redefined.
- Show a warning if a different compiler is used for building external
modules.
- Infer --target from ARCH for CC=clang to let you cross-compile the
kernel without CROSS_COMPILE.
- Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
- Add <linux/stdarg.h> to the kernel source instead of borrowing
<stdarg.h> from the compiler.
- Add Nick Desaulniers as a Kbuild reviewer.
- Drop stale cc-option tests.
- Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
to handle symbols in inline assembly.
- Show a warning if 'FORCE' is missing for if_changed rules.
- Various cleanups
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Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add -s option (strict mode) to merge_config.sh to make it fail when
any symbol is redefined.
- Show a warning if a different compiler is used for building external
modules.
- Infer --target from ARCH for CC=clang to let you cross-compile the
kernel without CROSS_COMPILE.
- Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
- Add <linux/stdarg.h> to the kernel source instead of borrowing
<stdarg.h> from the compiler.
- Add Nick Desaulniers as a Kbuild reviewer.
- Drop stale cc-option tests.
- Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
to handle symbols in inline assembly.
- Show a warning if 'FORCE' is missing for if_changed rules.
- Various cleanups
* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
kbuild: redo fake deps at include/ksym/*.h
kbuild: clean up objtool_args slightly
modpost: get the *.mod file path more simply
checkkconfigsymbols.py: Fix the '--ignore' option
kbuild: merge vmlinux_link() between ARCH=um and other architectures
kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
kbuild: remove stale *.symversions
kbuild: remove unused quiet_cmd_update_lto_symversions
gen_compile_commands: extract compiler command from a series of commands
x86: remove cc-option-yn test for -mtune=
arc: replace cc-option-yn uses with cc-option
s390: replace cc-option-yn uses with cc-option
ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
sparc: move the install rule to arch/sparc/Makefile
security: remove unneeded subdir-$(CONFIG_...)
kbuild: sh: remove unused install script
kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
kbuild: Switch to 'f' variants of integrated assembler flag
kbuild: Shuffle blank line to improve comment meaning
...
Merge misc updates from Andrew Morton:
"173 patches.
Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
oom-kill, migration, ksm, percpu, vmstat, and madvise)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
mm/madvise: add MADV_WILLNEED to process_madvise()
mm/vmstat: remove unneeded return value
mm/vmstat: simplify the array size calculation
mm/vmstat: correct some wrong comments
mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
selftests: vm: add COW time test for KSM pages
selftests: vm: add KSM merging time test
mm: KSM: fix data type
selftests: vm: add KSM merging across nodes test
selftests: vm: add KSM zero page merging test
selftests: vm: add KSM unmerge test
selftests: vm: add KSM merge test
mm/migrate: correct kernel-doc notation
mm: wire up syscall process_mrelease
mm: introduce process_mrelease system call
memblock: make memblock_find_in_range method private
mm/mempolicy.c: use in_task() in mempolicy_slab_node()
mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
mm/mempolicy: advertise new MPOL_PREFERRED_MANY
mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
...
Split off from prev patch in the series that implements the syscall.
Link: https://lkml.kernel.org/r/20210809185259.405936-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The bdflush system call has been deprecated for a very long time.
Recently Michael Schmitz tested[1] and found that the last known
caller of of the bdflush system call is unaffected by it's removal.
Since the code is not needed delete it.
[1] https://lkml.kernel.org/r/36123b5d-daa0-6c2b-f2d4-a942f069fd54@gmail.com
Link: https://lkml.kernel.org/r/87sg10quue.fsf_-_@disp2133
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull misc fs updates from Jan Kara:
"The new quotactl_fd() syscall (remake of quotactl_path() syscall that
got introduced & disabled in 5.13 cycle), and couple of udf, reiserfs,
isofs, and writeback fixes and cleanups"
* tag 'fs_for_v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
writeback: fix obtain a reference to a freeing memcg css
quota: remove unnecessary oom message
isofs: remove redundant continue statement
quota: Wire up quotactl_fd syscall
quota: Change quotactl_path() systcall to an fd-based one
reiserfs: Remove unneed check in reiserfs_write_full_page()
udf: Fix NULL pointer dereference in udf_symlink function
reiserfs: add check for invalid 1st journal block
- Consolidate the macros for .byte ... opcode sequences
- Deduplicate register offset defines in include files
- Simplify the ia32,x32 compat handling of the related syscall tables to
get rid of #ifdeffery.
- Clear all EFLAGS which are not required for syscall handling
- Consolidate the syscall tables and switch the generation over to the
generic shell script and remove the CFLAGS tweaks which are not longer
required.
- Use 'int' type for system call numbers to match the generic code.
- Add more selftests for syscalls
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Merge tag 'x86-entry-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 entry code related updates from Thomas Gleixner:
- Consolidate the macros for .byte ... opcode sequences
- Deduplicate register offset defines in include files
- Simplify the ia32,x32 compat handling of the related syscall tables
to get rid of #ifdeffery.
- Clear all EFLAGS which are not required for syscall handling
- Consolidate the syscall tables and switch the generation over to the
generic shell script and remove the CFLAGS tweaks which are not
longer required.
- Use 'int' type for system call numbers to match the generic code.
- Add more selftests for syscalls
* tag 'x86-entry-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/syscalls: Don't adjust CFLAGS for syscall tables
x86/syscalls: Remove -Wno-override-init for syscall tables
x86/uml/syscalls: Remove array index from syscall initializers
x86/syscalls: Clear 'offset' and 'prefix' in case they are set in env
x86/entry: Use int everywhere for system call numbers
x86/entry: Treat out of range and gap system calls the same
x86/entry/64: Sign-extend system calls on entry to int
selftests/x86/syscall: Add tests under ptrace to syscall_numbering_64
selftests/x86/syscall: Simplify message reporting in syscall_numbering
selftests/x86/syscall: Update and extend syscall_numbering_64
x86/syscalls: Switch to generic syscallhdr.sh
x86/syscalls: Use __NR_syscalls instead of __NR_syscall_max
x86/unistd: Define X32_NR_syscalls only for 64-bit kernel
x86/syscalls: Stop filling syscall arrays with *_sys_ni_syscall
x86/syscalls: Switch to generic syscalltbl.sh
x86/entry/x32: Rename __x32_compat_sys_* to __x64_compat_sys_*
- Micro-optimize and standardize the do_syscall_64() calling convention
- Make syscall entry flags clearing more conservative
- Clean up syscall table handling
- Clean up & standardize assembly macros, in preparation of FRED
- Misc cleanups and fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-asm-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
- Micro-optimize and standardize the do_syscall_64() calling convention
- Make syscall entry flags clearing more conservative
- Clean up syscall table handling
- Clean up & standardize assembly macros, in preparation of FRED
- Misc cleanups and fixes
* tag 'x86-asm-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Make <asm/asm.h> valid on cross-builds as well
x86/regs: Syscall_get_nr() returns -1 for a non-system call
x86/entry: Split PUSH_AND_CLEAR_REGS into two submacros
x86/syscall: Maximize MSR_SYSCALL_MASK
x86/syscall: Unconditionally prototype {ia32,x32}_sys_call_table[]
x86/entry: Reverse arguments to do_syscall_64()
x86/entry: Unify definitions from <asm/calling.h> and <asm/ptrace-abi.h>
x86/asm: Use _ASM_BYTES() in <asm/nops.h>
x86/asm: Add _ASM_BYTES() macro for a .byte ... opcode sequence
x86/asm: Have the __ASM_FORM macros handle commas in arguments
on code executed in the guest and handle the case where failure to
get the RIP would result in a #GP, as it should, instead of in a #PF
- Disable interrupts while the per-CPU GHCB is held
- Split the #VC handler depending on where the #VC exception has
happened and therefore provide for precise context tracking like the
rest of the exception handlers deal with noinstr regions now
- Add defines for the GHCB version 2 protocol so that further shared
development with KVM can happen without merge conflicts
- The usual small cleanups
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Merge tag 'x86_sev_for_v5.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov:
- Differentiate the type of exception the #VC handler raises depending
on code executed in the guest and handle the case where failure to
get the RIP would result in a #GP, as it should, instead of in a #PF
- Disable interrupts while the per-CPU GHCB is held
- Split the #VC handler depending on where the #VC exception has
happened and therefore provide for precise context tracking like the
rest of the exception handlers deal with noinstr regions now
- Add defines for the GHCB version 2 protocol so that further shared
development with KVM can happen without merge conflicts
- The usual small cleanups
* tag 'x86_sev_for_v5.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Use "SEV: " prefix for messages from sev.c
x86/sev: Add defines for GHCB version 2 MSR protocol requests
x86/sev: Split up runtime #VC handler for correct state tracking
x86/sev: Make sure IRQs are disabled while GHCB is active
x86/sev: Propagate #GP if getting linear instruction address failed
x86/insn: Extend error reporting from insn_fetch_from_user[_inatomic]()
x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip()
x86/sev: Fix error message in runtime #VC handler
Split up the #VC handler code into a from-user and a from-kernel part.
This allows clean and correct state tracking, as the #VC handler needs
to enter NMI-state when raised from kernel mode and plain IRQ state when
raised from user-mode.
Fixes: 62441a1fb5 ("x86/sev-es: Correctly track IRQ states in runtime #VC handler")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210618115409.22735-3-joro@8bytes.org
The syscall_*.c files only contain data (the syscall tables). There
is no need to adjust CFLAGS for tracing and stack protector since they
contain no code.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210524181707.132844-4-brgerst@gmail.com
Commit 44fe4895f4 ("Stop filling syscall arrays with *_sys_ni_syscall")
removes the need for -Wno-override-init, since the table is now filled
sequentially instead of overriding a default value.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210524181707.132844-3-brgerst@gmail.com
If the environment variable 'prefix' is set on the build host, it is
wrongly used as syscall macro prefixes.
$ export prefix=/usr
$ make -s defconfig all
In file included from ./arch/x86/include/asm/unistd.h:20,
from <stdin>:2:
./arch/x86/include/generated/uapi/asm/unistd_64.h:4:9: warning: missing whitespace after the macro name
4 | #define __NR_/usrread 0
| ^~~~~
arch/x86/entry/syscalls/Makefile should clear 'offset' and 'prefix'.
Fixes: 3cba325b35 ("x86/syscalls: Switch to generic syscallhdr.sh")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210525115420.679416-1-masahiroy@kernel.org
System call numbers are defined as int, so use int everywhere for system
call numbers. This is strictly a cleanup; it should not change anything
user visible; all ABI changes have been done in the preceeding patches.
[ tglx: Replaced the unsigned long cast ]
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210518191303.4135296-7-hpa@zytor.com
The current 64-bit system call entry code treats out-of-range system
calls differently than system calls that map to a hole in the system
call table.
This is visible to the user if system calls are intercepted via ptrace or
seccomp and the return value (regs->ax) is modified: in the former case,
the return value is preserved, and in the latter case, sys_ni_syscall() is
called and the return value is forced to -ENOSYS.
The API spec in <asm-generic/syscalls.h> is very clear that only
(int)-1 is the non-system-call sentinel value, so make the system call
behavior consistent by calling sys_ni_syscall() for all invalid system
call numbers except for -1.
Although currently sys_ni_syscall() simply returns -ENOSYS, calling it
explicitly is friendly for tracing and future possible extensions, and
as this is an error path there is no reason to optimize it.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210518191303.4135296-6-hpa@zytor.com
Right now, *some* code will treat e.g. 0x0000000100000001 as a system
call and some will not. Some of the code, notably in ptrace, will
treat 0x000000018000000 as a system call and some will not. Finally,
right now, e.g. 335 for x86-64 will force the exit code to be set to
-ENOSYS even if poked by ptrace, but 548 will not, because there is an
observable difference between an out of range system call and a system
call number that falls outside the range of the table.
This is visible to the user: for example, the syscall_numbering_64
test fails if run under strace, because as strace uses ptrace, it ends
up clobbering the upper half of the 64-bit system call number.
The architecture independent code all assumes that a system call is "int"
that the value -1 specifically and not just any negative value is used for
a non-system call. This is the case on x86 as well when arch-independent
code is involved. The arch-independent API is defined/documented (but not
*implemented*!) in <asm-generic/syscall.h>.
This is an ABI change, but is in fact a revert to the original x86-64
ABI. The original assembly entry code would zero-extend the system call
number;
Use sign extend to be explicit that this is treated as a signed number
(although in practice it makes no difference, of course) and to avoid
people getting the idea of "optimizing" it, as has happened on at least
two(!) separate occasions.
Do not store the extended value into regs->orig_ax, however: on x86-64, the
ABI is that the callee is responsible for extending parameters, so only
examining the lower 32 bits is fully consistent with any "int" argument to
any system call, e.g. regs->di for write(2). The full value of %rax on
entry to the kernel is thus still available.
[ tglx: Add a comment to the ASM code ]
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210518191303.4135296-5-hpa@zytor.com
Many architectures duplicate similar shell scripts.
Converts x86 to use scripts/syscallhdr.sh.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210517073815.97426-7-masahiroy@kernel.org
