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Tue, 15 Oct 2024 16:43:28 +0000 (GMT) From: Claudio Imbrenda To: linux-kernel@vger.kernel.org Cc: borntraeger@de.ibm.com, nsg@linux.ibm.com, nrb@linux.ibm.com, frankja@linux.ibm.com, seiden@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com, gor@linux.ibm.com, gerald.schaefer@linux.ibm.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH v3 10/11] s390/mm: Get rid of fault type switch statements Date: Tue, 15 Oct 2024 18:43:25 +0200 Message-ID: <20241015164326.124987-11-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241015164326.124987-1-imbrenda@linux.ibm.com> References: <20241015164326.124987-1-imbrenda@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 4btRNoVUpFamlLieAt3rpuCttRKOy1ab X-Proofpoint-ORIG-GUID: 4btRNoVUpFamlLieAt3rpuCttRKOy1ab X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 clxscore=1015 suspectscore=0 phishscore=0 impostorscore=0 mlxscore=0 spamscore=0 bulkscore=0 lowpriorityscore=0 priorityscore=1501 mlxlogscore=956 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410150113 Content-Type: text/plain; charset="utf-8" From: Heiko Carstens With GMAP_FAULT fault type gone, there are only KERNEL_FAULT and USER_FAULT fault types left. Therefore there is no need for any fault type switch statements left. Rename get_fault_type() into is_kernel_fault() and let it return a boolean value. Change all switch statements to if statements. This removes quite a bit of code. Signed-off-by: Heiko Carstens Reviewed-by: Alexander Gordeev --- arch/s390/mm/fault.c | 70 ++++++++++++++------------------------------ 1 file changed, 22 insertions(+), 48 deletions(-) diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 6e96fc7905fc..93ae097ef0e0 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -46,11 +46,6 @@ #include #include "../kernel/entry.h" =20 -enum fault_type { - KERNEL_FAULT, - USER_FAULT, -}; - static DEFINE_STATIC_KEY_FALSE(have_store_indication); =20 static int __init fault_init(void) @@ -64,15 +59,15 @@ early_initcall(fault_init); /* * Find out which address space caused the exception. */ -static enum fault_type get_fault_type(struct pt_regs *regs) +static bool is_kernel_fault(struct pt_regs *regs) { union teid teid =3D { .val =3D regs->int_parm_long }; =20 if (user_mode(regs)) - return USER_FAULT; + return false; if (teid.as =3D=3D PSW_BITS_AS_SECONDARY) - return USER_FAULT; - return KERNEL_FAULT; + return false; + return true; } =20 static unsigned long get_fault_address(struct pt_regs *regs) @@ -167,17 +162,12 @@ static void dump_fault_info(struct pt_regs *regs) break; } pr_cont("mode while using "); - switch (get_fault_type(regs)) { - case USER_FAULT: - asce =3D get_lowcore()->user_asce.val; - pr_cont("user "); - break; - case KERNEL_FAULT: + if (is_kernel_fault(regs)) { asce =3D get_lowcore()->kernel_asce.val; pr_cont("kernel "); - break; - default: - unreachable(); + } else { + asce =3D get_lowcore()->user_asce.val; + pr_cont("user "); } pr_cont("ASCE.\n"); dump_pagetable(asce, get_fault_address(regs)); @@ -212,7 +202,6 @@ static void do_sigsegv(struct pt_regs *regs, int si_cod= e) =20 static void handle_fault_error_nolock(struct pt_regs *regs, int si_code) { - enum fault_type fault_type; unsigned long address; bool is_write; =20 @@ -223,17 +212,15 @@ static void handle_fault_error_nolock(struct pt_regs = *regs, int si_code) } if (fixup_exception(regs)) return; - fault_type =3D get_fault_type(regs); - if (fault_type =3D=3D KERNEL_FAULT) { + if (is_kernel_fault(regs)) { address =3D get_fault_address(regs); is_write =3D fault_is_write(regs); if (kfence_handle_page_fault(address, is_write, regs)) return; - } - if (fault_type =3D=3D KERNEL_FAULT) pr_alert("Unable to handle kernel pointer dereference in virtual kernel = address space\n"); - else + } else { pr_alert("Unable to handle kernel paging request in virtual user address= space\n"); + } dump_fault_info(regs); die(regs, "Oops"); } @@ -267,7 +254,6 @@ static void do_exception(struct pt_regs *regs, int acce= ss) struct vm_area_struct *vma; unsigned long address; struct mm_struct *mm; - enum fault_type type; unsigned int flags; vm_fault_t fault; bool is_write; @@ -282,15 +268,8 @@ static void do_exception(struct pt_regs *regs, int acc= ess) mm =3D current->mm; address =3D get_fault_address(regs); is_write =3D fault_is_write(regs); - type =3D get_fault_type(regs); - switch (type) { - case KERNEL_FAULT: + if (is_kernel_fault(regs) || faulthandler_disabled() || !mm) return handle_fault_error_nolock(regs, 0); - case USER_FAULT: - if (faulthandler_disabled() || !mm) - return handle_fault_error_nolock(regs, 0); - break; - } perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); flags =3D FAULT_FLAG_DEFAULT; if (user_mode(regs)) @@ -460,8 +439,15 @@ void do_secure_storage_access(struct pt_regs *regs) */ panic("Unexpected PGM 0x3d with TEID bit 61=3D0"); } - switch (get_fault_type(regs)) { - case USER_FAULT: + if (is_kernel_fault(regs)) { + folio =3D phys_to_folio(addr); + if (unlikely(!folio_try_get(folio))) + return; + rc =3D arch_make_folio_accessible(folio); + folio_put(folio); + if (rc) + BUG(); + } else { mm =3D current->mm; mmap_read_lock(mm); vma =3D find_vma(mm, addr); @@ -470,7 +456,7 @@ void do_secure_storage_access(struct pt_regs *regs) folio =3D folio_walk_start(&fw, vma, addr, 0); if (!folio) { mmap_read_unlock(mm); - break; + return; } /* arch_make_folio_accessible() needs a raised refcount. */ folio_get(folio); @@ -480,18 +466,6 @@ void do_secure_storage_access(struct pt_regs *regs) if (rc) send_sig(SIGSEGV, current, 0); mmap_read_unlock(mm); - break; - case KERNEL_FAULT: - folio =3D phys_to_folio(addr); - if (unlikely(!folio_try_get(folio))) - break; - rc =3D arch_make_folio_accessible(folio); - folio_put(folio); - if (rc) - BUG(); - break; - default: - unreachable(); } } NOKPROBE_SYMBOL(do_secure_storage_access); --=20 2.47.0