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ftrace does not use text_poke() for enabling trace functionality. It uses
its own mechanism and flips the whole kernel text to RW and back to RO.
The CPA rework removed a loop based check of 4k pages which tried to
preserve a large page by checking each 4k page whether the change would
actually cover all pages in the large page.
This resulted in endless loops for nothing as in testing it turned out that
it actually never preserved anything. Of course testing missed to include
ftrace, which is the one and only case which benefitted from the 4k loop.
As a consequence enabling function tracing or ftrace based kprobes results
in a full 4k split of the kernel text, which affects iTLB performance.
The kernel RO protection is the only valid case where this can actually
preserve large pages.
All other static protections (RO data, data NX, PCI, BIOS) are truly
static. So a conflict with those protections which results in a split
should only ever happen when a change of memory next to a protected region
is attempted. But these conflicts are rightfully splitting the large page
to preserve the protected regions. In fact a change to the protected
regions itself is a bug and is warned about.
Add an exception for the static protection check for kernel text RO when
the to be changed region spawns a full large page which allows to preserve
the large mappings. This also prevents the syslog to be spammed about CPA
violations when ftrace is used.
The exception needs to be removed once ftrace switched over to text_poke()
which avoids the whole issue.
Fixes: 585948f4f695 ("x86/mm/cpa: Avoid the 4k pages check completely")
Reported-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282355340.1938@nanos.tec.linutronix.de
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GCC9 build warning
One of the very few warnings I have in the current build comes from
arch/x86/boot/edd.c, where I get the following with a gcc9 build:
arch/x86/boot/edd.c: In function ‘query_edd’:
arch/x86/boot/edd.c:148:11: warning: taking address of packed member of ‘struct boot_params’ may result in an unaligned pointer value [-Waddress-of-packed-member]
148 | mbrptr = boot_params.edd_mbr_sig_buffer;
| ^~~~~~~~~~~
This warning triggers because we throw away all the CFLAGS and then make
a new set for REALMODE_CFLAGS, so the -Wno-address-of-packed-member we
added in the following commit is not present:
6f303d60534c ("gcc-9: silence 'address-of-packed-member' warning")
The simplest solution for now is to adjust the warning for this version
of CFLAGS as well, but it would definitely make sense to examine whether
REALMODE_CFLAGS could be derived from CFLAGS, so that it picks up changes
in the compiler flags environment automatically.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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find_trampoline_placement()
Gustavo noticed that 'new' can be left uninitialized if 'bios_start'
happens to be less or equal to 'entry->addr + entry->size'.
Initialize the variable at the begin of the iteration to the current value
of 'bios_start'.
Fixes: 0a46fff2f910 ("x86/boot/compressed/64: Fix boot on machines with broken E820 table")
Reported-by: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190826133326.7cxb4vbmiawffv2r@box
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Although APIC initialization will typically clear out the LDR before
setting it, the APIC cleanup code should reset the LDR.
This was discovered with a 32-bit KVM guest jumping into a kdump
kernel. The stale bits in the LDR triggered a bug in the KVM APIC
implementation which caused the destination mapping for VCPUs to be
corrupted.
Note that this isn't intended to paper over the KVM APIC bug. The kernel
has to clear the LDR when resetting the APIC registers except when X2APIC
is enabled.
This lacks a Fixes tag because missing to clear LDR goes way back into pre
git history.
[ tglx: Made x2apic_enabled a function call as required ]
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190826101513.5080-3-bsd@redhat.com
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Legacy apic init uses bigsmp for smp systems with 8 and more CPUs. The
bigsmp APIC implementation uses physical destination mode, but it
nevertheless initializes LDR and DFR. The LDR even ends up incorrectly with
multiple bit being set.
This does not cause a functional problem because LDR and DFR are ignored
when physical destination mode is active, but it triggered a problem on a
32-bit KVM guest which jumps into a kdump kernel.
The multiple bits set unearthed a bug in the KVM APIC implementation. The
code which creates the logical destination map for VCPUs ignores the
disabled state of the APIC and ends up overwriting an existing valid entry
and as a result, APIC calibration hangs in the guest during kdump
initialization.
Remove the bogus LDR/DFR initialization.
This is not intended to work around the KVM APIC bug. The LDR/DFR
ininitalization is wrong on its own.
The issue goes back into the pre git history. The fixes tag is the commit
in the bitkeeper import which introduced bigsmp support in 2003.
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: db7b9e9f26b8 ("[PATCH] Clustered APIC setup for >8 CPU systems")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190826101513.5080-2-bsd@redhat.com
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32-bit processes running on a 64-bit kernel are not always detected
correctly, causing the process to crash when uretprobes are installed.
The reason for the crash is that in_ia32_syscall() is used to determine the
process's mode, which only works correctly when called from a syscall.
In the case of uretprobes, however, the function is called from a exception
and always returns 'false' on a 64-bit kernel. In consequence this leads to
corruption of the process's return address.
Fix this by using user_64bit_mode() instead of in_ia32_syscall(), which
is correct in any situation.
[ tglx: Add a comment and the following historical info ]
This should have been detected by the rename which happened in commit
abfb9498ee13 ("x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()")
which states in the changelog:
The is_ia32_task()/is_x32_task() function names are a big misnomer: they
suggests that the compat-ness of a system call is a task property, which
is not true, the compatness of a system call purely depends on how it
was invoked through the system call layer.
.....
and then it went and blindly renamed every call site.
Sadly enough this was already mentioned here:
8faaed1b9f50 ("uprobes/x86: Introduce sizeof_long(), cleanup adjust_ret_addr() and
arch_uretprobe_hijack_return_addr()")
where the changelog says:
TODO: is_ia32_task() is not what we actually want, TS_COMPAT does
not necessarily mean 32bit. Fortunately syscall-like insns can't be
probed so it actually works, but it would be better to rename and
use is_ia32_frame().
and goes all the way back to:
0326f5a94dde ("uprobes/core: Handle breakpoint and singlestep exceptions")
Oh well. 7+ years until someone actually tried a uretprobe on a 32bit
process on a 64bit kernel....
Fixes: 0326f5a94dde ("uprobes/core: Handle breakpoint and singlestep exceptions")
Signed-off-by: Sebastian Mayr <me@sam.st>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190728152617.7308-1-me@sam.st
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Rahul Tanwar reported the following bug on DT systems:
> 'ioapic_dynirq_base' contains the virtual IRQ base number. Presently, it is
> updated to the end of hardware IRQ numbers but this is done only when IOAPIC
> configuration type is IOAPIC_DOMAIN_LEGACY or IOAPIC_DOMAIN_STRICT. There is
> a third type IOAPIC_DOMAIN_DYNAMIC which applies when IOAPIC configuration
> comes from devicetree.
>
> See dtb_add_ioapic() in arch/x86/kernel/devicetree.c
>
> In case of IOAPIC_DOMAIN_DYNAMIC (DT/OF based system), 'ioapic_dynirq_base'
> remains to zero initialized value. This means that for OF based systems,
> virtual IRQ base will get set to zero.
Such systems will very likely not even boot.
For DT enabled machines ioapic_dynirq_base is irrelevant and not
updated, so simply map the IRQ base 1:1 instead.
Reported-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Tested-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alan@linux.intel.com
Cc: bp@alien8.de
Cc: cheol.yong.kim@intel.com
Cc: qi-ming.wu@intel.com
Cc: rahul.tanwar@intel.com
Cc: rppt@linux.ibm.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/20190821081330.1187-1-rahul.tanwar@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Use 'lea' instead of 'add' when adjusting %rsp in CALL_NOSPEC so as to
avoid clobbering flags.
KVM's emulator makes indirect calls into a jump table of sorts, where
the destination of the CALL_NOSPEC is a small blob of code that performs
fast emulation by executing the target instruction with fixed operands.
adcb_al_dl:
0x000339f8 <+0>: adc %dl,%al
0x000339fa <+2>: ret
A major motiviation for doing fast emulation is to leverage the CPU to
handle consumption and manipulation of arithmetic flags, i.e. RFLAGS is
both an input and output to the target of CALL_NOSPEC. Clobbering flags
results in all sorts of incorrect emulation, e.g. Jcc instructions often
take the wrong path. Sans the nops...
asm("push %[flags]; popf; " CALL_NOSPEC " ; pushf; pop %[flags]\n"
0x0003595a <+58>: mov 0xc0(%ebx),%eax
0x00035960 <+64>: mov 0x60(%ebx),%edx
0x00035963 <+67>: mov 0x90(%ebx),%ecx
0x00035969 <+73>: push %edi
0x0003596a <+74>: popf
0x0003596b <+75>: call *%esi
0x000359a0 <+128>: pushf
0x000359a1 <+129>: pop %edi
0x000359a2 <+130>: mov %eax,0xc0(%ebx)
0x000359b1 <+145>: mov %edx,0x60(%ebx)
ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK);
0x000359a8 <+136>: mov -0x10(%ebp),%eax
0x000359ab <+139>: and $0x8d5,%edi
0x000359b4 <+148>: and $0xfffff72a,%eax
0x000359b9 <+153>: or %eax,%edi
0x000359bd <+157>: mov %edi,0x4(%ebx)
For the most part this has gone unnoticed as emulation of guest code
that can trigger fast emulation is effectively limited to MMIO when
running on modern hardware, and MMIO is rarely, if ever, accessed by
instructions that affect or consume flags.
Breakage is almost instantaneous when running with unrestricted guest
disabled, in which case KVM must emulate all instructions when the guest
has invalid state, e.g. when the guest is in Big Real Mode during early
BIOS.
Fixes: 776b043848fd2 ("x86/retpoline: Add initial retpoline support")
Fixes: 1a29b5b7f347a ("KVM: x86: Make indirect calls in emulator speculation safe")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190822211122.27579-1-sean.j.christopherson@intel.com
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commit a90118c445cc ("x86/boot: Save fields explicitly, zero out everything
else") had two errors:
* It preserved boot_params.acpi_rsdp_addr, and
* It failed to preserve boot_params.hdr
Therefore, zero out acpi_rsdp_addr, and preserve hdr.
Fixes: a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else")
Reported-by: Neil MacLeod <neil@nmacleod.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Neil MacLeod <neil@nmacleod.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190821192513.20126-1-jhubbard@nvidia.com
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There have been reports of RDRAND issues after resuming from suspend on
some AMD family 15h and family 16h systems. This issue stems from a BIOS
not performing the proper steps during resume to ensure RDRAND continues
to function properly.
RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be
reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND
support using CPUID, including the kernel, will believe that RDRAND is
not supported.
Update the CPU initialization to clear the RDRAND CPUID bit for any family
15h and 16h processor that supports RDRAND. If it is known that the family
15h or family 16h system does not have an RDRAND resume issue or that the
system will not be placed in suspend, the "rdrand=force" kernel parameter
can be used to stop the clearing of the RDRAND CPUID bit.
Additionally, update the suspend and resume path to save and restore the
MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in
place after resuming from suspend.
Note, that clearing the RDRAND CPUID bit does not prevent a processor
that normally supports the RDRAND instruction from executing it. So any
code that determined the support based on family and model won't #UD.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chen Yu <yu.c.chen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
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BIOS on Samsung 500C Chromebook reports very rudimentary E820 table that
consists of 2 entries:
BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] usable
BIOS-e820: [mem 0x00000000fffff000-0x00000000ffffffff] reserved
It breaks logic in find_trampoline_placement(): bios_start lands on the
end of the first 4k page and trampoline start gets placed below 0.
Detect underflow and don't touch bios_start for such cases. It makes
kernel ignore E820 table on machines that doesn't have two usable pages
below BIOS_START_MAX.
Fixes: 1b3a62643660 ("x86/boot/compressed/64: Validate trampoline placement against E820")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203463
Link: https://lkml.kernel.org/r/20190813131654.24378-1-kirill.shutemov@linux.intel.com
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Some newer machines do not advertise legacy timers. The kernel can handle
that situation if the TSC and the CPU frequency are enumerated by CPUID or
MSRs and the CPU supports TSC deadline timer. If the CPU does not support
TSC deadline timer the local APIC timer frequency has to be known as well.
Some Ryzens machines do not advertize legacy timers, but there is no
reliable way to determine the bus frequency which feeds the local APIC
timer when the machine allows overclocking of that frequency.
As there is no legacy timer the local APIC timer calibration crashes due to
a NULL pointer dereference when accessing the not installed global clock
event device.
Switch the calibration loop to a non interrupt based one, which polls
either TSC (if frequency is known) or jiffies. The latter requires a global
clockevent. As the machines which do not have a global clockevent installed
have a known TSC frequency this is a non issue. For older machines where
TSC frequency is not known, there is no known case where the legacy timers
do not exist as that would have been reported long ago.
Reported-by: Daniel Drake <drake@endlessm.com>
Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Drake <drake@endlessm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908091443030.21433@nanos.tec.linutronix.de
Link: http://bugzilla.opensuse.org/show_bug.cgi?id=1142926#c12
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Dave Hansen spelled out the rules in an e-mail:
https://lkml.kernel.org/r/91eefbe4-e32b-d762-be4d-672ff915db47@intel.com
Copy those right into the <asm/intel-family.h> file to make it easy for
people to find them.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190815224704.GA10025@agluck-desk2.amr.corp.intel.com
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Recent gcc compilers (gcc 9.1) generate warnings about an out of bounds
memset, if the memset goes accross several fields of a struct. This
generated a couple of warnings on x86_64 builds in sanitize_boot_params().
Fix this by explicitly saving the fields in struct boot_params
that are intended to be preserved, and zeroing all the rest.
[ tglx: Tagged for stable as it breaks the warning free build there as well ]
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubbard@nvidia.com
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/home/tglx/work/kernel/linus/linux/arch/x86/math-emu/errors.c: In function ‘FPU_printall’:
/home/tglx/work/kernel/linus/linux/arch/x86/math-emu/errors.c:187:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
tagi = FPU_Special(r);
~~~~~^~~~~~~~~~~~~~~~
/home/tglx/work/kernel/linus/linux/arch/x86/math-emu/errors.c:188:3: note: here
case TAG_Valid:
^~~~
/home/tglx/work/kernel/linus/linux/arch/x86/math-emu/fpu_trig.c: In function ‘fyl2xp1’:
/home/tglx/work/kernel/linus/linux/arch/x86/math-emu/fpu_trig.c:1353:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (denormal_operand() < 0)
^
/home/tglx/work/kernel/linus/linux/arch/x86/math-emu/fpu_trig.c:1356:3: note: here
case TAG_Zero:
Remove the pointless 'break;' after 'continue;' while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Fix
arch/x86/kernel/apic/probe_32.c: In function ‘default_setup_apic_routing’:
arch/x86/kernel/apic/probe_32.c:146:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (!APIC_XAPIC(version)) {
^
arch/x86/kernel/apic/probe_32.c:151:3: note: here
case X86_VENDOR_HYGON:
^~~~
for 32-bit builds.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190811154036.29805-1-bp@alien8.de
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Currently, failure of cpuhp_setup_state() is ignored and the syscore ops
and the control interfaces can still be added even after the failure. But,
this error handling will cause a few issues:
1. The CPUs may have different values in the IA32_UMWAIT_CONTROL
MSR because there is no way to roll back the control MSR on
the CPUs which already set the MSR before the failure.
2. If the sysfs interface is added successfully, there will be a mismatch
between the global control value and the control MSR:
- The interface shows the default global control value. But,
the control MSR is not set to the value because the CPU online
function, which is supposed to set the MSR to the value,
is not installed.
- If the sysadmin changes the global control value through
the interface, the control MSR on all current online CPUs is
set to the new value. But, the control MSR on newly onlined CPUs
after the value change will not be set to the new value due to
lack of the CPU online function.
3. On resume from suspend/hibernation, the boot CPU restores the control
MSR to the global control value through the syscore ops. But, the
control MSR on all APs is not set due to lake of the CPU online
function.
To solve the issues and enforce consistent behavior on the failure
of the CPU hotplug setup, make the following changes:
1. Cache the original control MSR value which is configured by
hardware or BIOS before kernel boot. This value is likely to
be 0. But it could be a different number as well. Cache the
control MSR only once before the MSR is changed.
2. Add the CPU offline function so that the MSR is restored to the
original control value on all CPUs on the failure.
3. On the failure, exit from cpumait_init() so that the syscore ops
and the control interfaces are not added.
Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1565401237-60936-1-git-send-email-fenghua.yu@intel.com
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git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Paul Walmsley:
"A few minor RISC-V updates for v5.3-rc4:
- Remove __udivdi3() from the 32-bit Linux port, converting the only
upstream user to use do_div(), per Linux policy
- Convert the RISC-V standard clocksource away from per-cpu data
structures, since only one is used by Linux, even on a multi-CPU
system
- A set of DT binding updates that remove an obsolete text binding in
favor of a YAML binding, fix a bogus compatible string in the
schema (thus fixing a "make dtbs_check" warning), and clarifies the
future values expected in one of the RISC-V CPU properties"
* tag 'riscv/for-v5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
dt-bindings: riscv: fix the schema compatible string for the HiFive Unleashed board
dt-bindings: riscv: remove obsolete cpus.txt
RISC-V: Remove udivdi3
riscv: delay: use do_div() instead of __udivdi3()
dt-bindings: Update the riscv,isa string description
RISC-V: Remove per cpu clocksource
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A few fixes for x86:
- Don't reset the carefully adjusted build flags for the purgatory
and remove the unwanted flags instead. The 'reset all' approach led
to build fails under certain circumstances.
- Unbreak CLANG build of the purgatory by avoiding the builtin
memcpy/memset implementations.
- Address missing prototype warnings by including the proper header
- Fix yet more fall-through issues"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/lib/cpu: Address missing prototypes warning
x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
x86/purgatory: Do not use __builtin_memcpy and __builtin_memset
x86: mtrr: cyrix: Mark expected switch fall-through
x86/ptrace: Mark expected switch fall-through
|
|
for clang
A compilation -Wimplicit-fallthrough warning was enabled by commit
a035d552a93b ("Makefile: Globally enable fall-through warning")
Even though clang 10.0.0 does not currently support this warning without
a patch, clang currently does not support a value for this option.
Link: https://bugs.llvm.org/show_bug.cgi?id=39382
The gcc default for this warning is 3 so removing the =3 has no effect
for gcc and enables the warning for patched versions of clang.
Also remove the =3 from an existing use in a parisc Makefile:
arch/parisc/math-emu/Makefile
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fix from Michael Ellerman:
"Just one fix, a revert of a commit that was meant to be a minor
improvement to some inline asm, but ended up having no real benefit
with GCC and broke booting 32-bit machines when using Clang.
Thanks to: Arnd Bergmann, Christophe Leroy, Nathan Chancellor, Nick
Desaulniers, Segher Boessenkool"
* tag 'powerpc-5.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
Revert "powerpc: slightly improve cache helpers"
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull fall-through fixes from Gustavo A. R. Silva:
"Mark more switch cases where we are expecting to fall through, fixing
fall-through warnings in arm, sparc64, mips, i386 and s390"
* tag 'Wimplicit-fallthrough-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
ARM: ep93xx: Mark expected switch fall-through
scsi: fas216: Mark expected switch fall-throughs
pcmcia: db1xxx_ss: Mark expected switch fall-throughs
video: fbdev: omapfb_main: Mark expected switch fall-throughs
watchdog: riowd: Mark expected switch fall-through
s390/net: Mark expected switch fall-throughs
crypto: ux500/crypt: Mark expected switch fall-throughs
watchdog: wdt977: Mark expected switch fall-through
watchdog: scx200_wdt: Mark expected switch fall-through
watchdog: Mark expected switch fall-throughs
ARM: signal: Mark expected switch fall-through
mfd: omap-usb-host: Mark expected switch fall-throughs
mfd: db8500-prcmu: Mark expected switch fall-throughs
ARM: OMAP: dma: Mark expected switch fall-throughs
ARM: alignment: Mark expected switch fall-throughs
ARM: tegra: Mark expected switch fall-through
ARM/hw_breakpoint: Mark expected switch fall-throughs
|
|
Mark switch cases where we are expecting to fall through.
Fix the following warnings (Building: arm-ep93xx_defconfig arm):
arch/arm/mach-ep93xx/crunch.c: In function 'crunch_do':
arch/arm/mach-ep93xx/crunch.c:46:3: warning: this statement may
fall through [-Wimplicit-fallthrough=]
memset(crunch_state, 0, sizeof(*crunch_state));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-ep93xx/crunch.c:53:2: note: here
case THREAD_NOTIFY_EXIT:
^~~~
Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning:
arch/arm/kernel/signal.c: In function 'do_signal':
arch/arm/kernel/signal.c:598:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
restart -= 2;
~~~~~~~~^~~~
arch/arm/kernel/signal.c:599:3: note: here
case -ERESTARTNOHAND:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/plat-omap/dma.c: In function 'omap_set_dma_src_burst_mode':
arch/arm/plat-omap/dma.c:384:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dma_omap2plus()) {
^
arch/arm/plat-omap/dma.c:393:2: note: here
case OMAP_DMA_DATA_BURST_16:
^~~~
arch/arm/plat-omap/dma.c:394:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dma_omap2plus()) {
^
arch/arm/plat-omap/dma.c:402:2: note: here
default:
^~~~~~~
arch/arm/plat-omap/dma.c: In function 'omap_set_dma_dest_burst_mode':
arch/arm/plat-omap/dma.c:473:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dma_omap2plus()) {
^
arch/arm/plat-omap/dma.c:481:2: note: here
default:
^~~~~~~
Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/mm/alignment.c: In function 'thumb2arm':
arch/arm/mm/alignment.c:688:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((tinstr & (3 << 9)) == 0x0400) {
^
arch/arm/mm/alignment.c:700:2: note: here
default:
^~~~~~~
arch/arm/mm/alignment.c: In function 'do_alignment_t32_to_handler':
arch/arm/mm/alignment.c:753:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
poffset->un = (tinst2 & 0xff) << 2;
~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
arch/arm/mm/alignment.c:754:2: note: here
case 0xe940:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning:
arch/arm/mach-tegra/reset.c: In function 'tegra_cpu_reset_handler_enable':
arch/arm/mach-tegra/reset.c:72:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
tegra_cpu_reset_handler_set(reset_address);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-tegra/reset.c:74:2: note: here
case 0:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_arch_parse':
arch/arm/kernel/hw_breakpoint.c:609:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
^
arch/arm/kernel/hw_breakpoint.c:611:2: note: here
case 3:
^~~~
arch/arm/kernel/hw_breakpoint.c:613:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
^
arch/arm/kernel/hw_breakpoint.c:615:2: note: here
default:
^~~~~~~
arch/arm/kernel/hw_breakpoint.c: In function 'arch_build_bp_info':
arch/arm/kernel/hw_breakpoint.c:544:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
^
arch/arm/kernel/hw_breakpoint.c:547:2: note: here
default:
^~~~~~~
In file included from include/linux/kernel.h:11,
from include/linux/list.h:9,
from include/linux/preempt.h:11,
from include/linux/hardirq.h:5,
from arch/arm/kernel/hw_breakpoint.c:16:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_pending':
include/linux/compiler.h:78:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:136:2: note: in expansion of macro 'unlikely'
unlikely(__ret_warn_on); \
^~~~~~~~
arch/arm/kernel/hw_breakpoint.c:863:3: note: in expansion of macro 'WARN'
WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
^~~~
arch/arm/kernel/hw_breakpoint.c:864:2: note: here
case ARM_ENTRY_SYNC_WATCHPOINT:
^~~~
arch/arm/kernel/hw_breakpoint.c: In function 'core_has_os_save_restore':
arch/arm/kernel/hw_breakpoint.c:910:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (oslsr & ARM_OSLSR_OSLM0)
^
arch/arm/kernel/hw_breakpoint.c:912:2: note: here
default:
^~~~~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Pull kvm fixes from Paolo Bonzini:
"Bugfixes (arm and x86) and cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
selftests: kvm: Adding config fragments
KVM: selftests: Update gitignore file for latest changes
kvm: remove unnecessary PageReserved check
KVM: arm/arm64: vgic: Reevaluate level sensitive interrupts on enable
KVM: arm: Don't write junk to CP15 registers on reset
KVM: arm64: Don't write junk to sysregs on reset
KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block
x86: kvm: remove useless calls to kvm_para_available
KVM: no need to check return value of debugfs_create functions
KVM: remove kvm_arch_has_vcpu_debugfs()
KVM: Fix leak vCPU's VMCS value into other pCPU
KVM: Check preempted_in_kernel for involuntary preemption
KVM: LAPIC: Don't need to wakeup vCPU twice afer timer fire
arm64: KVM: hyp: debug-sr: Mark expected switch fall-through
KVM: arm64: Update kvm_arm_exception_class and esr_class_str for new EC
KVM: arm: vgic-v3: Mark expected switch fall-through
arm64: KVM: regmap: Fix unexpected switch fall-through
KVM: arm/arm64: Introduce kvm_pmu_vcpu_init() to setup PMU counter index
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fix from Catalin Marinas:
"Fix bad_pte warning caused by pte_mkdevmap() not setting PTE_SPECIAL"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: mm: add missing PTE_SPECIAL in pte_mkdevmap on arm64
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:
- Map vdso also for statically linked binaries like all other
architectures.
- Fix no .bss usage compile-time check to account common objects with
the help of binutils size tool. Top level Makefile change acked-by
Masahiro.
- A fix to make perf happy with _etext symbol type.
- Fix dump_pagetables which is broken since p*d_offset implementation
change to comply with mm/gup.c expectations.
- Revert memory sharing for diag calls in protected virtualization,
since this is not required after all.
- Couple of other minor code cleanups.
* tag 's390-5.3-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/vdso: map vdso also for statically linked binaries
s390/build: use size command to perform empty .bss check
kbuild: add OBJSIZE variable for the size tool
s390: put _stext and _etext into .text section
s390/head64: cleanup unused labels
s390/unwind: remove stack recursion warning
s390/setup: adjust start_code of init_mm to _text
s390/mm: fix dump_pagetables top level page table walking
s390/protvirt: avoid memory sharing for diag 308 set/store
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm fixes for 5.3, take #2
- Fix our system register reset so that we stop writing
non-sensical values to them, and track which registers
get reset instead.
- Sync VMCR back from the GIC on WFI so that KVM has an
exact vue of PMR.
- Reevaluate state of HW-mapped, level triggered interrupts
on enable.
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm fixes for 5.3
- A bunch of switch/case fall-through annotation, fixing one actual bug
- Fix PMU reset bug
- Add missing exception class debug strings
|
|
s390 does not map the vdso for statically linked binaries, assuming
that this doesn't make sense. See commit fc5243d98ac2 ("[S390]
arch_setup_additional_pages arguments").
However with glibc commit d665367f596d ("linux: Enable vDSO for static
linking as default (BZ#19767)") and commit 5e855c895401 ("s390: Enable
VDSO for static linking") the vdso is also used for statically linked
binaries - if the kernel would make it available.
Therefore map the vdso always, just like all other architectures.
Reported-by: Stefan Liebler <stli@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
|
|
At the moment, the way we reset CP15 registers is mildly insane:
We write junk to them, call the reset functions, and then check that
we have something else in them.
The "fun" thing is that this can happen while the guest is running
(PSCI, for example). If anything in KVM has to evaluate the state
of a CP15 register while junk is in there, bad thing may happen.
Let's stop doing that. Instead, we track that we have called a
reset function for that register, and assume that the reset
function has done something.
In the end, the very need of this reset check is pretty dubious,
as it doesn't check everything (a lot of the CP15 reg leave outside
of the cp15_regs[] array). It may well be axed in the near future.
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
At the moment, the way we reset system registers is mildly insane:
We write junk to them, call the reset functions, and then check that
we have something else in them.
The "fun" thing is that this can happen while the guest is running
(PSCI, for example). If anything in KVM has to evaluate the state
of a system register while junk is in there, bad thing may happen.
Let's stop doing that. Instead, we track that we have called a
reset function for that register, and assume that the reset
function has done something. This requires fixing a couple of
sysreg refinition in the trap table.
In the end, the very need of this reset check is pretty dubious,
as it doesn't check everything (a lot of the sysregs leave outside of
the sys_regs[] array). It may well be axed in the near future.
Tested-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
This should never have landed in the first place: it was added as part
of 64-bit divide support for 32-bit systems, but the kernel doesn't
allow this sort of division. I must have forgotten to remove it.
This patch removes the support. Since this routine only worked on
64-bit platforms but was only built on 32-bit platforms, it's
essentially just nonsense anyway.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://lore.kernel.org/linux-riscv/nycvar.YSQ.7.76.1908061413360.19480@knanqh.ubzr/T/#t
Reported-by: Eric Lin <tesheng@andestech.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
|
|
In preparation for removing __udivdi3() from the RISC-V
architecture-specific files, convert its one user to use do_div().
This avoids breaking the RV32 build after __udivdi3() is removed.
This second version removes the assignment of the remainder to an
unused temporary variable. Thanks to Nicolas Pitre <nico@fluxnic.net>
for the suggestion.
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
|
|
Without this patch, the MAP_SYNC test case will cause a print_bad_pte
warning on arm64 as follows:
[ 25.542693] BUG: Bad page map in process mapdax333 pte:2e8000448800f53 pmd:41ff5f003
[ 25.546360] page:ffff7e0010220000 refcount:1 mapcount:-1 mapping:ffff8003e29c7440 index:0x0
[ 25.550281] ext4_dax_aops
[ 25.550282] name:"__aaabbbcccddd__"
[ 25.551553] flags: 0x3ffff0000001002(referenced|reserved)
[ 25.555802] raw: 03ffff0000001002 ffff8003dfffa908 0000000000000000 ffff8003e29c7440
[ 25.559446] raw: 0000000000000000 0000000000000000 00000001fffffffe 0000000000000000
[ 25.563075] page dumped because: bad pte
[ 25.564938] addr:0000ffffbe05b000 vm_flags:208000fb anon_vma:0000000000000000 mapping:ffff8003e29c7440 index:0
[ 25.574272] file:__aaabbbcccddd__ fault:ext4_dax_fault mmmmap:ext4_file_mmap readpage:0x0
[ 25.578799] CPU: 1 PID: 1180 Comm: mapdax333 Not tainted 5.2.0+ #21
[ 25.581702] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 25.585624] Call trace:
[ 25.587008] dump_backtrace+0x0/0x178
[ 25.588799] show_stack+0x24/0x30
[ 25.590328] dump_stack+0xa8/0xcc
[ 25.591901] print_bad_pte+0x18c/0x218
[ 25.593628] unmap_page_range+0x778/0xc00
[ 25.595506] unmap_single_vma+0x94/0xe8
[ 25.597304] unmap_vmas+0x90/0x108
[ 25.598901] unmap_region+0xc0/0x128
[ 25.600566] __do_munmap+0x284/0x3f0
[ 25.602245] __vm_munmap+0x78/0xe0
[ 25.603820] __arm64_sys_munmap+0x34/0x48
[ 25.605709] el0_svc_common.constprop.0+0x78/0x168
[ 25.607956] el0_svc_handler+0x34/0x90
[ 25.609698] el0_svc+0x8/0xc
[...]
The root cause is in _vm_normal_page, without the PTE_SPECIAL bit,
the return value will be incorrectly set to pfn_to_page(pfn) instead
of NULL. Besides, this patch also rewrite the pmd_mkdevmap to avoid
setting PTE_SPECIAL for pmd
The MAP_SYNC test case is as follows(Provided by Yibo Cai)
$#include <stdio.h>
$#include <string.h>
$#include <unistd.h>
$#include <sys/file.h>
$#include <sys/mman.h>
$#ifndef MAP_SYNC
$#define MAP_SYNC 0x80000
$#endif
/* mount -o dax /dev/pmem0 /mnt */
$#define F "/mnt/__aaabbbcccddd__"
int main(void)
{
int fd;
char buf[4096];
void *addr;
if ((fd = open(F, O_CREAT|O_TRUNC|O_RDWR, 0644)) < 0) {
perror("open1");
return 1;
}
if (write(fd, buf, 4096) != 4096) {
perror("lseek");
return 1;
}
addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_SYNC, fd, 0);
if (addr == MAP_FAILED) {
perror("mmap");
printf("did you mount with '-o dax'?\n");
return 1;
}
memset(addr, 0x55, 4096);
if (munmap(addr, 4096) == -1) {
perror("munmap");
return 1;
}
close(fd);
return 0;
}
Fixes: 73b20c84d42d ("arm64: mm: implement pte_devmap support")
Reported-by: Yibo Cai <Yibo.Cai@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Robin Murphy <Robin.Murphy@arm.com>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
Currently empty .bss checks performed do not pay attention to "common
objects" in object files which end up in .bss section eventually.
The "size" tool is a part of binutils and since version 2.18 provides
"--common" command line option, which allows to account "common objects"
sizes in .bss section size. Utilize "size --common" to perform accurate
check that .bss section is unused. Besides that the size tool handles
object files without .bss section gracefully and doesn't require
additional objdump run.
The linux kernel requires binutils 2.20 since 4.13.
Kbuild exports OBJSIZE to reference the right size tool.
Link: http://lkml.kernel.org/r/patch-2.thread-2257a1.git-2257a1c53d4a.your-ad-here.call-01565088755-ext-5120@work.hours
Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
|
|
When building with W=1, warnings about missing prototypes are emitted:
CC arch/x86/lib/cpu.o
arch/x86/lib/cpu.c:5:14: warning: no previous prototype for 'x86_family' [-Wmissing-prototypes]
5 | unsigned int x86_family(unsigned int sig)
| ^~~~~~~~~~
arch/x86/lib/cpu.c:18:14: warning: no previous prototype for 'x86_model' [-Wmissing-prototypes]
18 | unsigned int x86_model(unsigned int sig)
| ^~~~~~~~~
arch/x86/lib/cpu.c:33:14: warning: no previous prototype for 'x86_stepping' [-Wmissing-prototypes]
33 | unsigned int x86_stepping(unsigned int sig)
| ^~~~~~~~~~~~
Add the proper include file so the prototypes are there.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/42513.1565234837@turing-police
|
|
KBUILD_CFLAGS is very carefully built up in the top level Makefile,
particularly when cross compiling or using different build tools.
Resetting KBUILD_CFLAGS via := assignment is an antipattern.
The comment above the reset mentions that -pg is problematic. Other
Makefiles use `CFLAGS_REMOVE_file.o = $(CC_FLAGS_FTRACE)` when
CONFIG_FUNCTION_TRACER is set. Prefer that pattern to wiping out all of
the important KBUILD_CFLAGS then manually having to re-add them. Seems
also that __stack_chk_fail references are generated when using
CONFIG_STACKPROTECTOR or CONFIG_STACKPROTECTOR_STRONG.
Fixes: 8fc5b4d4121c ("purgatory: core purgatory functionality")
Reported-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190807221539.94583-2-ndesaulniers@google.com
|
|
Implementing memcpy and memset in terms of __builtin_memcpy and
__builtin_memset is problematic.
GCC at -O2 will replace calls to the builtins with calls to memcpy and
memset (but will generate an inline implementation at -Os). Clang will
replace the builtins with these calls regardless of optimization level.
$ llvm-objdump -dr arch/x86/purgatory/string.o | tail
0000000000000339 memcpy:
339: 48 b8 00 00 00 00 00 00 00 00 movabsq $0, %rax
000000000000033b: R_X86_64_64 memcpy
343: ff e0 jmpq *%rax
0000000000000345 memset:
345: 48 b8 00 00 00 00 00 00 00 00 movabsq $0, %rax
0000000000000347: R_X86_64_64 memset
34f: ff e0
Such code results in infinite recursion at runtime. This is observed
when doing kexec.
Instead, reuse an implementation from arch/x86/boot/compressed/string.c.
This requires to implement a stub function for warn(). Also, Clang may
lower memcmp's that compare against 0 to bcmp's, so add a small definition,
too. See also: commit 5f074f3e192f ("lib/string.c: implement a basic bcmp")
Fixes: 8fc5b4d4121c ("purgatory: core purgatory functionality")
Reported-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Debugged-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Debugged-by: Manoj Gupta <manojgupta@google.com>
Suggested-by: Alistair Delva <adelva@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Cc: stable@vger.kernel.org
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=984056
Link: https://lkml.kernel.org/r/20190807221539.94583-1-ndesaulniers@google.com
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Mark switch cases where we are expecting to fall through.
Fix the following warning (Building: i386_defconfig i386):
arch/x86/kernel/cpu/mtrr/cyrix.c:99:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20190805201712.GA19927@embeddedor
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Mark switch cases where we are expecting to fall through.
Fix the following warning (Building: allnoconfig i386):
arch/x86/kernel/ptrace.c:202:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (unlikely(value == 0))
^
arch/x86/kernel/ptrace.c:206:2: note: here
default:
^~~~~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20190805195654.GA17831@embeddedor
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git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS fixes from Paul Burton:
"A few MIPS fixes for 5.3:
- Various switch fall through annotations to fixup warnings & errors
resulting from -Wimplicit-fallthrough.
- A fix for systems (at least jazz) using an i8253 PIT as clocksource
when it's not suitably configured.
- Set struct cacheinfo's cpu_map_populated field to true, indicating
that we filled in cache info detected from cop0 registers &
avoiding complaints about that info being (intentionally) missing
in devicetree"
* tag 'mips_fixes_5.3_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: BCM63XX: Mark expected switch fall-through
MIPS: OProfile: Mark expected switch fall-throughs
MIPS: Annotate fall-through in Cavium Octeon code
MIPS: Annotate fall-through in kvm/emulate.c
mips: fix cacheinfo
MIPS: kernel: only use i8253 clocksource with periodic clockevent
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull pti updates from Thomas Gleixner:
"The performance deterioration departement is not proud at all to
present yet another set of speculation fences to mitigate the next
chapter in the 'what could possibly go wrong' story.
The new vulnerability belongs to the Spectre class and affects GS
based data accesses and has therefore been dubbed 'Grand Schemozzle'
for secret communication purposes. It's officially listed as
CVE-2019-1125.
Conditional branches in the entry paths which contain a SWAPGS
instruction (interrupts and exceptions) can be mis-speculated which
results in speculative accesses with a wrong GS base.
This can happen on entry from user mode through a mis-speculated
branch which takes the entry from kernel mode path and therefore does
not execute the SWAPGS instruction. The following speculative accesses
are done with user GS base.
On entry from kernel mode the mis-speculated branch executes the
SWAPGS instruction in the entry from user mode path which has the same
effect that the following GS based accesses are done with user GS
base.
If there is a disclosure gadget available in these code paths the
mis-speculated data access can be leaked through the usual side
channels.
The entry from user mode issue affects all CPUs which have speculative
execution. The entry from kernel mode issue affects only Intel CPUs
which can speculate through SWAPGS. On CPUs from other vendors SWAPGS
has semantics which prevent that.
SMAP migitates both problems but only when the CPU is not affected by
the Meltdown vulnerability.
The mitigation is to issue LFENCE instructions in the entry from
kernel mode path for all affected CPUs and on the affected Intel CPUs
also in the entry from user mode path unless PTI is enabled because
the CR3 write is serializing.
The fences are as usual enabled conditionally and can be completely
disabled on the kernel command line. The Spectre V1 documentation is
updated accordingly.
A big "Thank You!" goes to Josh for doing the heavy lifting for this
round of hardware misfeature 'repair'. Of course also "Thank You!" to
everybody else who contributed in one way or the other"
* 'x86/grand-schemozzle' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation: Add swapgs description to the Spectre v1 documentation
x86/speculation/swapgs: Exclude ATOMs from speculation through SWAPGS
x86/entry/64: Use JMP instead of JMPQ
x86/speculation: Enable Spectre v1 swapgs mitigations
x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations
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Perf relies on _etext and _stext symbols being one of 't', 'T', 'v' or
'V'. Put them into .text section to guarantee that.
Also moves padding to page boundary inside .text which has an effect that
.text section is now padded with nops rather than 0's, which apparently
has been the initial intention for specifying 0x0700 fill expression.
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Suggested-by: Andreas Krebbel <krebbel@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Cleanup labels in head64 some of which are not being used since git
recorded history.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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Remove pointless stack recursion on stack type ... warning, which
only confuses people. There is no way to make backchain unwinder 100%
reliable. When a task is interrupted in-between stack frame allocation
and backchain write instructions new stack frame backchain pointer is
left uninitialized (there are also sometimes additional instruction
in-between stack frame allocation and backchain write instructions due
to gcc shrink-wrapping). In attempt to unwind such stack the unwinder
would still try to use that invalid backchain value and perform all kind
of sanity checks on it to make sure we are not pointed out of stack. In
some cases that invalid backchain value would be 0 and we would falsely
treat next stackframe as pt_regs and again gprs[15] in those pt_regs
might happen to point at some address within the task's stack.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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