commit e32683c6f7d22ba624e0bfc58b02cf3348bdca63 upstream.
With binutils 2.26, RESERVE_BRK() causes a build failure:
/tmp/ccnGOKZ5.s: Assembler messages:
/tmp/ccnGOKZ5.s:98: Error: missing ')'
/tmp/ccnGOKZ5.s:98: Error: missing ')'
/tmp/ccnGOKZ5.s:98: Error: missing ')'
/tmp/ccnGOKZ5.s:98: Error: junk at end of line, first unrecognized
character is `U'
The problem is this line:
RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE)
Specifically, the INIT_PGT_BUF_SIZE macro which (via PAGE_SIZE's use
_AC()) has a "1UL", which makes older versions of the assembler unhappy.
Unfortunately the _AC() macro doesn't work for inline asm.
Inline asm was only needed here to convince the toolchain to add the
STT_NOBITS flag. However, if a C variable is placed in a section whose
name is prefixed with ".bss", GCC and Clang automatically set
STT_NOBITS. In fact, ".bss..page_aligned" already relies on this trick.
So fix the build failure (and simplify the macro) by allocating the
variable in C.
Also, add NOLOAD to the ".brk" output section clause in the linker
script. This is a failsafe in case the ".bss" prefix magic trick ever
stops working somehow. If there's a section type mismatch, the GNU
linker will force the ".brk" output section to be STT_NOBITS. The LLVM
linker will fail with a "section type mismatch" error.
Note this also changes the name of the variable from .brk.##name to
__brk_##name. The variable names aren't actually used anywhere, so it's
harmless.
Fixes: a1e2c031ec39 ("x86/mm: Simplify RESERVE_BRK()")
Reported-by: Joe Damato <jdamato@fastly.com>
Reported-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Joe Damato <jdamato@fastly.com>
Link: https://lore.kernel.org/r/22d07a44c80d8e8e1e82b9a806ddc8c6bbb2606e.1654759036.git.jpoimboe@kernel.org
[nathan: Fix trivial conflict due to lack of 81519f778830]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a1e2c031ec3949b8c039b739c0b5bf9c30007b00 upstream.
RESERVE_BRK() reserves data in the .brk_reservation section. The data
is initialized to zero, like BSS, so the macro specifies 'nobits' to
prevent the data from taking up space in the vmlinux binary. The only
way to get the compiler to do that (without putting the variable in .bss
proper) is to use inline asm.
The macro also has a hack which encloses the inline asm in a discarded
function, which allows the size to be passed (global inline asm doesn't
allow inputs).
Remove the need for the discarded function hack by just stringifying the
size rather than supplying it as an input to the inline asm.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220506121631.133110232@infradead.org
[nathan: Resolve conflict due to lack of 2b6ff7dea670]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 128b0c9781c9f2651bea163cb85e52a6c7be0f9e upstream.
David and a few others reported that on certain newer systems some legacy
interrupts fail to work correctly.
Debugging revealed that the BIOS of these systems leaves the legacy PIC in
uninitialized state which makes the PIC detection fail and the kernel
switches to a dummy implementation.
Unfortunately this fallback causes quite some code to fail as it depends on
checks for the number of legacy PIC interrupts or the availability of the
real PIC.
In theory there is no reason to use the PIC on any modern system when
IO/APIC is available, but the dependencies on the related checks cannot be
resolved trivially and on short notice. This needs lots of analysis and
rework.
The PIC detection has been added to avoid quirky checks and force selection
of the dummy implementation all over the place, especially in VM guest
scenarios. So it's not an option to revert the relevant commit as that
would break a lot of other scenarios.
One solution would be to try to initialize the PIC on detection fail and
retry the detection, but that puts the burden on everything which does not
have a PIC.
Fortunately the ACPI/MADT table header has a flag field, which advertises
in bit 0 that the system is PCAT compatible, which means it has a legacy
8259 PIC.
Evaluate that bit and if set avoid the detection routine and keep the real
PIC installed, which then gets initialized (for nothing) and makes the rest
of the code with all the dependencies work again.
Fixes: e179f6914152 ("x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately")
Reported-by: David Lazar <dlazar@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: David Lazar <dlazar@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218003
Link: https://lore.kernel.org/r/875y2u5s8g.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1f36cd05e0081f2c75769a551d584c4ffb2a5660 upstream.
Fault handler used to make non-trivial calls, so it needed
to set a stack frame up. Used to be
save ... - grab a stack frame, old %o... become %i...
....
ret - go back to address originally in %o7, currently %i7
restore - switch to previous stack frame, in delay slot
Non-trivial calls had been gone since ab5e8b331244 and that code should
have become
retl - go back to address in %o7
clr %o0 - have return value set to 0
What it had become instead was
ret - go back to address in %i7 - return address of *caller*
clr %o0 - have return value set to 0
which is not good, to put it mildly - we forcibly return 0 from
csum_and_copy_{from,to}_iter() (which is what the call of that
thing had been inlined into) and do that without dropping the
stack frame of said csum_and_copy_..._iter(). Confuses the
hell out of the caller of csum_and_copy_..._iter(), obviously...
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Fixes: ab5e8b331244 "sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic()"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rename freq_scale to a less generic name, as it will get exported soon
for modules. Since x86 already names its own implementation of this as
arch_freq_scale, lets stick to that.
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Since we are compiling for a single chipset that is known to support LSE,
the system_uses_lse_atomics() static branch can be eliminated entirely.
Therefore, make system_uses_lse_atomics() always true to always use LSE
atomics, and update ARM64_LSE_ATOMIC_INSN() users to get rid of the extra
nops used for alternatives patching at runtime.
This reduces generated code size by removing LL/SC atomics, which improves
instruction cache footprint.
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
commit c1ae1c59c8c6e0b66a718308c623e0cb394dab6b upstream.
Since the fixed commits both zdev->iommu_bitmap and zdev->lazy_bitmap
are allocated as vzalloc(zdev->iommu_pages / 8). The problem is that
zdev->iommu_bitmap is a pointer to unsigned long but the above only
yields an allocation that is a multiple of sizeof(unsigned long) which
is 8 on s390x if the number of IOMMU pages is a multiple of 64.
This in turn is the case only if the effective IOMMU aperture is
a multiple of 64 * 4K = 256K. This is usually the case and so didn't
cause visible issues since both the virt_to_phys(high_memory) reduced
limit and hardware limits use nice numbers.
Under KVM, and in particular with QEMU limiting the IOMMU aperture to
the vfio DMA limit (default 65535), it is possible for the reported
aperture not to be a multiple of 256K however. In this case we end up
with an iommu_bitmap whose allocation is not a multiple of
8 causing bitmap operations to access it out of bounds.
Sadly we can't just fix this in the obvious way and use bitmap_zalloc()
because for large RAM systems (tested on 8 TiB) the zdev->iommu_bitmap
grows too large for kmalloc(). So add our own bitmap_vzalloc() wrapper.
This might be a candidate for common code, but this area of code will
be replaced by the upcoming conversion to use the common code DMA API on
s390 so just add a local routine.
Fixes: 224593215525 ("s390/pci: use virtual memory for iommu bitmap")
Fixes: 13954fd6913a ("s390/pci_dma: improve lazy flush for unmap")
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5ad37b5e30433afa7a5513e3eb61f69fa0976785 ]
On mapphone devices we may get lots of noise on the micro-USB port in debug
uart mode until the phy-cpcap-usb driver probes. Let's limit the noise by
using overrun-throttle-ms.
Note that there is also a related separate issue where the charger cable
connected may cause random sysrq requests until phy-cpcap-usb probes that
still remains.
Cc: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Cc: Carl Philipp Klemm <philipp@uvos.xyz>
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Upstream commit: 63e44bc52047f182601e7817da969a105aa1f721
Check the memory operand of INS/OUTS before emulating the instruction.
The #VC exception can get raised from user-space, but the memory operand
can be manipulated to access kernel memory before the emulation actually
begins and after the exception handler has run.
[ bp: Massage commit message. ]
Fixes: 597cfe48212a ("x86/boot/compressed/64: Setup a GHCB-based VC Exception handler")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Upstream commit: b9cb9c45583b911e0db71d09caa6b56469eb2bdf
Check the IO permission bitmap (if present) before emulating IOIO #VC
exceptions for user-space. These permissions are checked by hardware
already before the #VC is raised, but due to the VC-handler decoding
race it needs to be checked again in software.
Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Dohrmann <erbse.13@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Upstream commit: a37cd2a59d0cb270b1bba568fd3a3b8668b9d3ba
A virt scenario can be constructed where MMIO memory can be user memory.
When that happens, a race condition opens between when the hardware
raises the #VC and when the #VC handler gets to emulate the instruction.
If the MOVS is replaced with a MOVS accessing kernel memory in that
small race window, then write to kernel memory happens as the access
checks are not done at emulation time.
Disable MMIO emulation in user mode temporarily until a sensible use
case appears and justifies properly handling the race window.
Fixes: 0118b604c2c9 ("x86/sev-es: Handle MMIO String Instructions")
Reported-by: Tom Dohrmann <erbse.13@gmx.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Dohrmann <erbse.13@gmx.de>
Cc: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a16eb25b09c02a54c1c1b449d4b6cfa2cf3f013a upstream.
Per the SDM, "When the local APIC handles a performance-monitoring
counters interrupt, it automatically sets the mask flag in the LVT
performance counter register." Add this behavior to KVM's local APIC
emulation.
Failure to mask the LVTPC entry results in spurious PMIs, e.g. when
running Linux as a guest, PMI handlers that do a "late_ack" spew a large
number of "dazed and confused" spurious NMI warnings.
Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests")
Cc: stable@vger.kernel.org
Signed-off-by: Jim Mattson <jmattson@google.com>
Tested-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230925173448.3518223-3-mizhang@google.com
[sean: massage changelog, correct Fixes]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 223d3a0d30b6e9f979f5642e430e1753d3e29f89 upstream.
If CONFIG_SWP_EMULATION is not set and
CONFIG_CP15_BARRIER_EMULATION is not set,
aarch64-linux-gnu complained about unused-function :
arch/arm64/kernel/armv8_deprecated.c:67:21: error: ‘aarch32_check_condition’ defined but not used [-Werror=unused-function]
static unsigned int aarch32_check_condition(u32 opcode, u32 psr)
^~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
To fix this warning, modify aarch32_check_condition() with __maybe_unused.
Fixes: 0c5f416219da ("arm64: armv8_deprecated: move aarch32 helper earlier")
Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20221124022429.19024-1-renzhijie2@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0c5f416219da3795dc8b33e5bb7865a6b3c4e55c upstream.
Subsequent patches will rework the logic in armv8_deprecated.c.
In preparation for subsequent changes, this patch moves some shared logic
earlier in the file. This will make subsequent diffs simpler and easier to
read.
At the same time, drop the `__kprobes` annotation from
aarch32_check_condition(), as this is only used for traps from compat
userspace, and has no risk of recursion within kprobes. As this is the
last kprobes annotation in armve8_deprecated.c, we no longer need to
include <asm/kprobes.h>.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221019144123.612388-9-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 25eeac0cfe7c97ade1be07340e11e7143aab57a6 upstream.
Subsequent patches will rework the logic in armv8_deprecated.c.
In preparation for subsequent changes, this patch moves the emulation
logic earlier in the file, and moves the infrastructure later in the
file. This will make subsequent diffs simpler and easier to read.
This is purely a move. There should be no functional change as a result
of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221019144123.612388-8-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b4453cc8a7ebbd45436a8cd3ffeaa069ceac146f upstream.
The code for emulating deprecated instructions has two related
structures: struct insn_emulation_ops and struct insn_emulation, where
each struct insn_emulation_ops is associated 1-1 with a struct
insn_emulation.
It would be simpler to combine the two into a single structure, removing
the need for (unconditional) dynamic allocation at boot time, and
simplifying some runtime pointer chasing.
This patch merges the two structures together.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221019144123.612388-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b3a0c010e900a9f89dcd99f10bd8f7538d21b0a9 upstream.
Currently do_sysinstr() and do_cp15instr() are marked with
NOKPROBE_SYMBOL(). However, these are only called for exceptions taken
from EL0, and there is no risk of recursion in kprobes, so this is not
necessary.
Remove the NOKPROBE_SYMBOL() annotation, and rename the two functions to
more clearly indicate that these are solely for exceptions taken from
EL0, better matching the names used by the lower level entry points in
entry-common.c.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221019144123.612388-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 18906ff9af6517c20763ed63dab602a4150794f7 upstream.
Recently, we reworked a lot of code to consistentlt pass ESR_ELx as a
64-bit quantity. However, we missed that this can be passed into die()
and __die() as the 'err' parameter where it is truncated to a 32-bit
int.
As notify_die() already takes 'err' as a long, this patch changes die()
and __die() to also take 'err' as a long, ensuring that the full value
of ESR_ELx is retained.
At the same time, die() is updated to consistently log 'err' as a
zero-padded 64-bit quantity.
Subsequent patches will pass the ESR_ELx value to die() for a number of
exceptions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220913101732.3925290-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d35652a5fc9944784f6f50a5c979518ff8dacf61 upstream.
Fei has reported that KASAN triggers during apply_alternatives() on
a 5-level paging machine:
BUG: KASAN: out-of-bounds in rcu_is_watching()
Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0
...
__asan_load4()
rcu_is_watching()
trace_hardirqs_on()
text_poke_early()
apply_alternatives()
...
On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57)
gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on
__VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled().
KASAN gets confused when apply_alternatives() patches the
KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START
static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue.
Fix it for real by disabling KASAN while the kernel is patching alternatives.
[ mingo: updated the changelog ]
Fixes: 6657fca06e3f ("x86/mm: Allow to boot without LA57 if CONFIG_X86_5LEVEL=y")
Reported-by: Fei Yang <fei.yang@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231012100424.1456-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5d9cea8a552ee122e21fbd5a3c5d4eb85f648e06 ]
On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing
_PAGE_USER.
But then pte_user() returns 1 also for PAGE_NONE.
As _PAGE_NA prevent reads, add a specific version of pte_read()
that returns 0 when _PAGE_NA is set instead of always returning 1.
Fixes: 351750331fc1 ("powerpc/mm: Introduce _PAGE_NA")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/57bcfbe578e43123f9ed73e040229b80f1ad56ec.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f454b18e07f518bcd0c05af17a2239138bff52de upstream.
Fix erratum #1485 on Zen4 parts where running with STIBP disabled can
cause an #UD exception. The performance impact of the fix is negligible.
Reported-by: René Rebe <rene@exactcode.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: René Rebe <rene@exactcode.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@exactcode.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2f1b0d3d733169eb11680bfa97c266ae5e757148 ]
The RISC-V architecture does not expose sub-registers, and hold all
32-bit values in a sign-extended format [1] [2]:
| The compiler and calling convention maintain an invariant that all
| 32-bit values are held in a sign-extended format in 64-bit
| registers. Even 32-bit unsigned integers extend bit 31 into bits
| 63 through 32. Consequently, conversion between unsigned and
| signed 32-bit integers is a no-op, as is conversion from a signed
| 32-bit integer to a signed 64-bit integer.
While BPF, on the other hand, exposes sub-registers, and use
zero-extension (similar to arm64/x86).
This has led to some subtle bugs, where a BPF JITted program has not
sign-extended the a0 register (return value in RISC-V land), passed
the return value up the kernel, e.g.:
| int from_bpf(void);
|
| long foo(void)
| {
| return from_bpf();
| }
Here, a0 would be 0xffff_ffff, instead of the expected
0xffff_ffff_ffff_ffff.
Internally, the RISC-V JIT uses a5 as a dedicated register for BPF
return values.
Keep a5 zero-extended, but explicitly sign-extend a0 (which is used
outside BPF land). Now that a0 (RISC-V ABI) and a5 (BPF ABI) differs,
a0 is only moved to a5 for non-BPF native calls (BPF_PSEUDO_CALL).
Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://github.com/riscv/riscv-isa-manual/releases/download/riscv-isa-release-056b6ff-2023-10-02/unpriv-isa-asciidoc.pdf # [2]
Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/draft-20230929-e5c800e661a53efe3c2678d71a306323b60eb13b/riscv-abi.pdf # [2]
Link: https://lore.kernel.org/bpf/20231004120706.52848-2-bjorn@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0fd1fd0104954380477353aea29c347e85dff16d ]
The current emit_call function is not suitable for kernel function call as
it store return value to bpf R0 register. We can separate it out for common
use. Meanwhile, simplify judgment logic, that is, fixed function address
can use jal or auipc+jalr, while the unfixed can use only auipc+jalr.
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/bpf/20230215135205.1411105-3-pulehui@huaweicloud.com
Stable-dep-of: 2f1b0d3d7331 ("riscv, bpf: Sign-extend return values")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit 447dabc1fedbafb1f9894e0c3054bf546a1af913
as it causes this issue with the Android build system:
out/soong/.intermediates/vendor/lineage/build/soong/generated_kernel_includes/ge
n/usr/include/asm/sigcontext.h:53:2: error: unknown type name '__uint128_t'
__uint128_t vregs[32];
^
1 error generated.