Re: [PATCH v12 08/22] selftests/vm: clear the bits in shadow reg when a pkey is freed.
On 02/21/2018 05:55 PM, Ram Pai wrote: > When a key is freed, the key is no more effective. > Clear the bits corresponding to the pkey in the shadow > register. Otherwise it will carry some spurious bits > which can trigger false-positive asserts. ... > diff --git a/tools/testing/selftests/vm/protection_keys.c > b/tools/testing/selftests/vm/protection_keys.c > index ca54a95..aaf9f09 100644 > --- a/tools/testing/selftests/vm/protection_keys.c > +++ b/tools/testing/selftests/vm/protection_keys.c > @@ -582,6 +582,9 @@ int alloc_pkey(void) > int sys_pkey_free(unsigned long pkey) > { > int ret = syscall(SYS_pkey_free, pkey); > + > + if (!ret) > + shadow_pkey_reg &= reset_bits(pkey, PKEY_DISABLE_ACCESS); > dprintf1("%s(pkey=%ld) syscall ret: %d\n", __func__, pkey, ret); > return ret; > } Did this cause problems for you in practice? On x86, sys_pkey_free() does not affect PKRU, so this isn't quite right. I'd much rather have the actual tests explicitly clear the PKRU bits and also in the process clear the shadow bits. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH v12 08/22] selftests/vm: clear the bits in shadow reg when a pkey is freed.
When a key is freed, the key is no more effective. Clear the bits corresponding to the pkey in the shadow register. Otherwise it will carry some spurious bits which can trigger false-positive asserts. cc: Dave Hansen cc: Florian Weimer Signed-off-by: Ram Pai --- tools/testing/selftests/vm/protection_keys.c |3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index ca54a95..aaf9f09 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -582,6 +582,9 @@ int alloc_pkey(void) int sys_pkey_free(unsigned long pkey) { int ret = syscall(SYS_pkey_free, pkey); + + if (!ret) + shadow_pkey_reg &= reset_bits(pkey, PKEY_DISABLE_ACCESS); dprintf1("%s(pkey=%ld) syscall ret: %d\n", __func__, pkey, ret); return ret; } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html