From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> We dump out the entire area of the siginfo where the si_pkey_ptr is supposed to be. But, we do some math on the poitner, which is a u32. We intended to do byte math, not u32 math on the pointer. Cast it over to a u8* so it works. Also, move this block of code to below th si_code check. It doesn't hurt anything, but the si_pkey field is gibberish for other signal types. Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Ram Pai <linuxram@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Michael Ellermen <mpe@xxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> --- b/tools/testing/selftests/x86/protection_keys.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff -puN tools/testing/selftests/x86/protection_keys.c~pkeys-selftests-fix-pointer-math tools/testing/selftests/x86/protection_keys.c --- a/tools/testing/selftests/x86/protection_keys.c~pkeys-selftests-fix-pointer-math 2018-03-21 15:47:50.374198921 -0700 +++ b/tools/testing/selftests/x86/protection_keys.c 2018-03-21 15:47:50.377198921 -0700 @@ -289,13 +289,6 @@ void signal_handler(int signum, siginfo_ dump_mem(pkru_ptr - 128, 256); pkey_assert(*pkru_ptr); - si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset); - dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr); - dump_mem(si_pkey_ptr - 8, 24); - siginfo_pkey = *si_pkey_ptr; - pkey_assert(siginfo_pkey < NR_PKEYS); - last_si_pkey = siginfo_pkey; - if ((si->si_code == SEGV_MAPERR) || (si->si_code == SEGV_ACCERR) || (si->si_code == SEGV_BNDERR)) { @@ -303,6 +296,13 @@ void signal_handler(int signum, siginfo_ exit(4); } + si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset); + dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr); + dump_mem((u8 *)si_pkey_ptr - 8, 24); + siginfo_pkey = *si_pkey_ptr; + pkey_assert(siginfo_pkey < NR_PKEYS); + last_si_pkey = siginfo_pkey; + dprintf1("signal pkru from xsave: %08x\n", *pkru_ptr); /* need __rdpkru() version so we do not do shadow_pkru checking */ dprintf1("signal pkru from pkru: %08x\n", __rdpkru()); _