On ARM hosts with CTR_EL0.DIC and CTR_EL0.IDC set, this would only cause
an ISB to be executed during cache maintenance, which could lead to QEMU
executing TBs containing garbage instructions.
This seems to be because the ISB finishes executing instructions and
flushes the pipeline, but the ISB doesn't guarantee that writes from the
executed instructions are committed. If a small enough TB is created, it's
possible that the writes setting up the TB aren't committed by the time the
TB is executed.
This function is intended to be a port of the gcc implementation
(85b46d0795/libgcc/config/aarch64/sync-cache.c (L67))
which makes the first DSB unconditional, so we can fix the synchronization
issue by doing that as well.
Cc: qemu-stable@nongnu.org
Fixes: 664a79735e ("util: Specialize flush_idcache_range for aarch64")
Signed-off-by: Joe Komlodi <komlodi@google.com>
Message-id: 20250310203622.1827940-2-komlodi@google.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit e6c38d2ab5)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
<libkern/OSCacheControl.h> describes sys_icache_invalidate() as
"equivalent to sys_cache_control(kCacheFunctionPrepareForExecution)",
having kCacheFunctionPrepareForExecution defined as:
/* Prepare memory for execution. This should be called
* after writing machine instructions to memory, before
* executing them. It syncs the dcache and icache. [...]
*/
Since the dcache is also sync'd, we can avoid the sys_dcache_flush()
call when both rx/rw pointers are equal.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230605195911.96033-1-philmd@linaro.org>
ctr_el0 access is privileged on this platform and fails as an illegal
instruction.
Windows does not offer a way to flush data cache from userspace, and
only FlushInstructionCache is available in Windows API.
The generic implementation of flush_idcache_range uses,
__builtin___clear_cache, which already use the FlushInstructionCache
function. So we rely on that.
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230221153006.20300-2-pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
When compiling qemu-fuzz-i386 on aarch64 host, clang reported the following
error:
../util/cacheflush.c:38:44: error: value size does not match register size
specified by the constraint and modifier [-Werror,-Wasm-operand-widths]
asm volatile("mrs\t%0, ctr_el0" : "=r"(save_ctr_el0));
^
../util/cacheflush.c:38:24: note: use constraint modifier "w"
asm volatile("mrs\t%0, ctr_el0" : "=r"(save_ctr_el0));
^~
%w0
Modify the type of save_ctr_el0 to uint64_t to fix it.
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Gan Qixin <ganqixin@huawei.com>
Message-Id: <20210115075656.717957-1-ganqixin@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
For darwin, the CTR_EL0 register is not accessible, but there
are system routines that we can use.
For other hosts, copy the single pointer implementation from
libgcc and modify it to support the double pointer interface
we require. This halves the number of cache operations required
when split-rwx is enabled.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We are shortly going to have a split rw/rx jit buffer. Depending
on the host, we need to flush the dcache at the rw data pointer and
flush the icache at the rx code pointer.
For now, the two passed pointers are identical, so there is no
effective change in behaviour.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
