871a7f6a9a
With FEAT_FPAC, AUT* instructions that fail authentication do not produce an error value but instead fault. For pauth-2, install a signal handler and verify it gets called. For pauth-4 and pauth-5, we are explicitly testing the error value, so there's nothing to test with FEAT_FPAC, so exit early. Adjust the makefile to use -cpu neoverse-v1, which has FEAT_EPAC but not FEAT_FPAC. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20230829232335.965414-2-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
#include <assert.h>
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#include "pauth.h"
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static int x;
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int main()
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{
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int *p0 = &x, *p1, *p2, *p3;
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unsigned long salt = 0;
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int pac_feature = get_pac_feature();
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/*
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* Exit if no PAuth or FEAT_FPAC, which will SIGILL on AUTDA failure
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* rather than return an error for us to check below.
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*/
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if (pac_feature == 0 || pac_feature >= 4) {
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return 0;
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}
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/*
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* With TBI enabled and a 48-bit VA, there are 7 bits of auth, and so
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* a 1/128 chance of auth = pac(ptr,key,salt) producing zero.
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* Find a salt that creates auth != 0.
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*/
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do {
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salt++;
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asm("pacda %0, %1" : "=r"(p1) : "r"(salt), "0"(p0));
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} while (p0 == p1);
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/*
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* This pac must fail, because the input pointer bears an encryption,
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* and so is not properly extended within bits [55:47]. This will
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* toggle bit 54 in the output...
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*/
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asm("pacda %0, %1" : "=r"(p2) : "r"(salt), "0"(p1));
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/* ... so that the aut must fail, setting bit 53 in the output ... */
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asm("autda %0, %1" : "=r"(p3) : "r"(salt), "0"(p2));
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/* ... which means this equality must not hold. */
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assert(p3 != p0);
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return 0;
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}
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