hw/core/cpu.h is already using struct forward declarations in some cases
to avoid inclusions, and otherwise CPUAddressSpace and CPUJumpCache
are only used together with their definition. CPUTLBEntryFull is
always used when their definition is available. Remove all three
from typedefs.h.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Due to missing headers, when including "tb-jmp-cache.h" we might get:
accel/tcg/tb-jmp-cache.h:21:21: error: field ‘rcu’ has incomplete type
21 | struct rcu_head rcu;
| ^~~
accel/tcg/tb-jmp-cache.h:24:9: error: unknown type name ‘vaddr’
24 | vaddr pc;
| ^~~~~
Add the missing "qemu/rcu.h" and "exec/cpu-common.h" headers.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240111162442.43755-1-philmd@linaro.org>
Unless I'm missing something egregious, the jmp cache is only every
populated with a valid entry by the same thread that reads the cache.
Therefore, the contents of any valid entry are always consistent and
there is no need for any acquire/release magic.
Indeed ->tb has to be accessed with atomics, because concurrent
invalidations would otherwise cause data races. But ->pc is only ever
accessed by one thread, and accesses to ->tb and ->pc within tb_lookup
can never race with another tb_lookup. While the TranslationBlock
(especially the flags) could be modified by a concurrent invalidation,
store-release and load-acquire operations on the cache entry would
not add any additional ordering beyond what you get from performing
the accesses within a single thread.
Because of this, there is really nothing to win in splitting the CF_PCREL
and !CF_PCREL paths. It is easier to just always use the ->pc field in
the jump cache.
I noticed this while working on splitting commit 8ed558ec0c
("accel/tcg: Introduce TARGET_TB_PCREL", 2022-10-04) into multiple
pieces, for the sake of finding a more fine-grained bisection
result for https://gitlab.com/qemu-project/qemu/-/issues/2092.
It does not (and does not intend to) fix that issue; therefore
it may make sense to not commit it until the root cause
of issue #2092 is found.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240122153409.351959-1-pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Related functions dealing with the jump cache are also updated.
Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230621135633.1649-8-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
tb-jmp-cache.h contains a few small functions that only exist to hide a
CF_PCREL check, however the caller often already performs such a check.
This patch moves CF_PCREL checks from the callee to the caller, and also
removes these functions which now only hide an access of the jmp-cache.
Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230227135202.9710-12-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230227135202.9710-5-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Fixes the appended use-after-free. The root cause is that
during tb invalidation we use CPU_FOREACH, and therefore
to safely free a vCPU we must wait for an RCU grace period
to elapse.
$ x86_64-linux-user/qemu-x86_64 tests/tcg/x86_64-linux-user/munmap-pthread
=================================================================
==1800604==ERROR: AddressSanitizer: heap-use-after-free on address 0x62d0005f7418 at pc 0x5593da6704eb bp 0x7f4961a7ac70 sp 0x7f4961a7ac60
READ of size 8 at 0x62d0005f7418 thread T2
#0 0x5593da6704ea in tb_jmp_cache_inval_tb ../accel/tcg/tb-maint.c:244
#1 0x5593da6704ea in do_tb_phys_invalidate ../accel/tcg/tb-maint.c:290
#2 0x5593da670631 in tb_phys_invalidate__locked ../accel/tcg/tb-maint.c:306
#3 0x5593da670631 in tb_invalidate_phys_page_range__locked ../accel/tcg/tb-maint.c:542
#4 0x5593da67106d in tb_invalidate_phys_range ../accel/tcg/tb-maint.c:614
#5 0x5593da6a64d4 in target_munmap ../linux-user/mmap.c:766
#6 0x5593da6dba05 in do_syscall1 ../linux-user/syscall.c:10105
#7 0x5593da6f564c in do_syscall ../linux-user/syscall.c:13329
#8 0x5593da49e80c in cpu_loop ../linux-user/x86_64/../i386/cpu_loop.c:233
#9 0x5593da6be28c in clone_func ../linux-user/syscall.c:6633
#10 0x7f496231cb42 in start_thread nptl/pthread_create.c:442
#11 0x7f49623ae9ff (/lib/x86_64-linux-gnu/libc.so.6+0x1269ff)
0x62d0005f7418 is located 28696 bytes inside of 32768-byte region [0x62d0005f0400,0x62d0005f8400)
freed by thread T148 here:
#0 0x7f49627b6460 in __interceptor_free ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:52
#1 0x5593da5ac057 in cpu_exec_unrealizefn ../cpu.c:180
#2 0x5593da81f851 (/home/cota/src/qemu/build/qemu-x86_64+0x484851)
Signed-off-by: Emilio Cota <cota@braap.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230111151628.320011-2-cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230124180127.1881110-27-alex.bennee@linaro.org>
Prepare for targets to be able to produce TBs that can
run in more than one virtual context.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Wrap the bare TranslationBlock pointer into a structure.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
