mirror of https://github.com/proxmox/mirror_qemu
linux-user/armeb: Fix __kernel_cmpxchg() for armeb
Commit7f4f0d9ea8
("linux-user/arm: Implement __kernel_cmpxchg with host atomics") switched to use qatomic_cmpxchg() to swap a word with the memory content, but missed to endianess-swap the oldval and newval values when emulating an armeb CPU, which expects words to be stored in big endian in the guest memory. The bug can be verified with qemu >= v7.0 on any little-endian host, when starting the armeb binary of the upx program, which just hangs without this patch. Cc: qemu-stable@nongnu.org Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: "Markus F.X.J. Oberhumer" <markus@oberhumer.com> Reported-by: John Reiser <jreiser@BitWagon.com> Closes: https://github.com/upx/upx/issues/687 Message-Id: <ZMQVnqY+F+5sTNFd@p100> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> (cherry picked from commit38dd78c41e
) Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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d53d3f07dc
commit
daa3277175
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@ -117,8 +117,9 @@ static void arm_kernel_cmpxchg32_helper(CPUARMState *env)
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{
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{
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uint32_t oldval, newval, val, addr, cpsr, *host_addr;
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uint32_t oldval, newval, val, addr, cpsr, *host_addr;
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oldval = env->regs[0];
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/* Swap if host != guest endianness, for the host cmpxchg below */
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newval = env->regs[1];
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oldval = tswap32(env->regs[0]);
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newval = tswap32(env->regs[1]);
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addr = env->regs[2];
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addr = env->regs[2];
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mmap_lock();
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mmap_lock();
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@ -174,6 +175,10 @@ static void arm_kernel_cmpxchg64_helper(CPUARMState *env)
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return;
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return;
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}
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}
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/* Swap if host != guest endianness, for the host cmpxchg below */
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oldval = tswap64(oldval);
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newval = tswap64(newval);
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#ifdef CONFIG_ATOMIC64
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#ifdef CONFIG_ATOMIC64
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val = qatomic_cmpxchg__nocheck(host_addr, oldval, newval);
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val = qatomic_cmpxchg__nocheck(host_addr, oldval, newval);
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cpsr = (val == oldval) * CPSR_C;
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cpsr = (val == oldval) * CPSR_C;
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