From c5a7392cfb965f70cff72155945a81ad62dd20a5 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 7 Mar 2019 13:15:34 +0100 Subject: [PATCH] s390x/tcg: Provide probe_write_access helper Instead of checking e.g. the first access on every touched page, we should check the actual access, otherwise we might get false positives when Low Address Protection (LAP) is active. As probe_write() can only deal with accesses to one page, we have to loop. Use i64 for the length, although not needed - easier to reuse TCG temps we already have in the translation functions where this will be used. Also allow it to be used from other helpers. Signed-off-by: David Hildenbrand Message-Id: <20190307121539.12842-28-david@redhat.com> [CH: add missing page_check_range()] Reviewed-by: Richard Henderson Signed-off-by: Cornelia Huck --- target/s390x/helper.h | 1 + target/s390x/internal.h | 2 ++ target/s390x/mem_helper.c | 26 ++++++++++++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/target/s390x/helper.h b/target/s390x/helper.h index 577edb384f..e2710f4fb3 100644 --- a/target/s390x/helper.h +++ b/target/s390x/helper.h @@ -123,6 +123,7 @@ DEF_HELPER_4(cu42, i32, env, i32, i32, i32) DEF_HELPER_5(msa, i32, env, i32, i32, i32, i32) DEF_HELPER_FLAGS_1(stpt, TCG_CALL_NO_RWG, i64, env) DEF_HELPER_FLAGS_1(stck, TCG_CALL_NO_RWG_SE, i64, env) +DEF_HELPER_FLAGS_3(probe_write_access, TCG_CALL_NO_WG, void, env, i64, i64) /* === Vector Support Instructions === */ DEF_HELPER_FLAGS_4(vll, TCG_CALL_NO_WG, void, env, ptr, i64, i64) diff --git a/target/s390x/internal.h b/target/s390x/internal.h index 07b69b8ea0..3b4855c175 100644 --- a/target/s390x/internal.h +++ b/target/s390x/internal.h @@ -349,6 +349,8 @@ void ioinst_handle_sal(S390CPU *cpu, uint64_t reg1, uintptr_t ra); /* mem_helper.c */ target_ulong mmu_real2abs(CPUS390XState *env, target_ulong raddr); +void probe_write_access(CPUS390XState *env, uint64_t addr, uint64_t len, + uintptr_t ra); /* mmu_helper.c */ diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c index a506d9ef99..3f76a8abfd 100644 --- a/target/s390x/mem_helper.c +++ b/target/s390x/mem_helper.c @@ -2623,3 +2623,29 @@ uint32_t HELPER(cu42)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t m3) return convert_unicode(env, r1, r2, m3, GETPC(), decode_utf32, encode_utf16); } + +void probe_write_access(CPUS390XState *env, uint64_t addr, uint64_t len, + uintptr_t ra) +{ +#ifdef CONFIG_USER_ONLY + if (!h2g_valid(addr) || !h2g_valid(addr + len - 1) || + page_check_range(addr, len, PAGE_WRITE) < 0) { + s390_program_interrupt(env, PGM_ADDRESSING, ILEN_AUTO, ra); + } +#else + /* test the actual access, not just any access to the page due to LAP */ + while (len) { + const uint64_t pagelen = -(addr | -TARGET_PAGE_MASK); + const uint64_t curlen = MIN(pagelen, len); + + probe_write(env, addr, curlen, cpu_mmu_index(env, false), ra); + addr = wrap_address(env, addr + curlen); + len -= curlen; + } +#endif +} + +void HELPER(probe_write_access)(CPUS390XState *env, uint64_t addr, uint64_t len) +{ + probe_write_access(env, addr, len, GETPC()); +}