From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Subject: selftests/vm/pkeys: handle negative sys_pkey_alloc() return code The alloc_pkey() sefltest function wraps the sys_pkey_alloc() system call. On success, it updates its "shadow" register value because sys_pkey_alloc() updates the real register. But, the success check is wrong. pkey_alloc() considers any non-zero return code to indicate success where the pkey register will be modified. This fails to take negative return codes into account. Consider only a positive return value as a successful call. Link: https://lkml.kernel.org/r/20210611164157.87AB4246@xxxxxxxxxxxxxxxxxx Fixes: 5f23f6d082a9 ("x86/pkeys: Add self-tests") Reported-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Tested-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Cc: Ram Pai <linuxram@xxxxxxxxxx> Cc: Sandipan Das <sandipan@xxxxxxxxxxxxx> Cc: Florian Weimer <fweimer@xxxxxxxxxx> Cc: "Desnes A. Nunes do Rosario" <desnesn@xxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Michal Suchanek <msuchanek@xxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/vm/protection_keys.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-handle-negative-sys_pkey_alloc-return-code +++ a/tools/testing/selftests/vm/protection_keys.c @@ -510,7 +510,7 @@ int alloc_pkey(void) " shadow: 0x%016llx\n", __func__, __LINE__, ret, __read_pkey_reg(), shadow_pkey_reg); - if (ret) { + if (ret > 0) { /* clear both the bits: */ shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret, ~PKEY_MASK); _
