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charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: MW6ODZvyxvNlmGGdMW-Idxhfp13rQb1X X-Proofpoint-ORIG-GUID: MW6ODZvyxvNlmGGdMW-Idxhfp13rQb1X X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-09_06,2023-03-08_03,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 adultscore=0 impostorscore=0 suspectscore=0 clxscore=1015 bulkscore=0 mlxlogscore=999 spamscore=0 mlxscore=0 phishscore=0 lowpriorityscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2303090087 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 55E7A40020 X-Rspam-User: X-Stat-Signature: yridhp88ppoor4s7rr8pukdmcprozape X-HE-Tag: 1678359872-439023 X-HE-Meta: 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 OIfVwi/X FZCiT2FRWETQumGmq7oa8n/sFdiB6SJMg3cqahSCOMC/2/w8s/zXjl6g3TWtk+asdn7dkWPGbSsoU4k8PnR24c59xoCm34QzhltaIvDHBpmoFl/FkszTqCKzLp42RAg6Eo0NdI6cTCMuAad3560qxq1fsqUEoI3QZy/CgyeHLrAXsY3DhvJr9zdbcHKBKJe+503WxTFIFB8YCvR/N5+7K7cwlEIxSefmoBTtV5Gf3iv7mIra6puQR5xpW5Jkl5FZC9ypZvyCJ37b237K9pLfCsl4WZaqjY3O0sSexlqGqB+Csp4H0hGQAXeyuO2STWKtfEPdATOOaRbdbJqqoedzI+GxcOZctKjsPpxcfjLr+WfYX6/U1ZEaFXDGWL3oDK4QXU7qBlu44oB2TzNC2ue50yyiT2w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Thanks Marco. On 2023/3/9 18:33, Marco Elver wrote: > On Thu, 9 Mar 2023 at 09:05, Zhenhua Huang wrote: >> >> Kfence only needs its pool to be mapped as page granularity, previous >> judgement was a bit over protected. Decouple it from judgement and do >> page granularity mapping for kfence pool only [1]. >> >> To implement this, also relocate the kfence pool allocation before the >> linear mapping setting up, kfence_alloc_pool is to allocate phys addr, >> __kfence_pool is to be set after linear mapping set up. >> >> LINK: [1] https://lore.kernel.org/linux-arm-kernel/1675750519-1064-1-git-send-email-quic_zhenhuah@quicinc.com/T/ >> Suggested-by: Mark Rutland >> Signed-off-by: Zhenhua Huang >> --- >> arch/arm64/mm/mmu.c | 24 ++++++++++++++++++++++++ >> arch/arm64/mm/pageattr.c | 5 ++--- >> include/linux/kfence.h | 10 ++++++++-- >> init/main.c | 1 - >> mm/kfence/core.c | 18 ++++++++++++++---- >> 5 files changed, 48 insertions(+), 10 deletions(-) >> >> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >> index 6f9d889..bd79691 100644 >> --- a/arch/arm64/mm/mmu.c >> +++ b/arch/arm64/mm/mmu.c >> @@ -24,6 +24,7 @@ >> #include >> #include >> #include >> +#include >> >> #include >> #include >> @@ -532,6 +533,9 @@ static void __init map_mem(pgd_t *pgdp) >> phys_addr_t kernel_end = __pa_symbol(__init_begin); >> phys_addr_t start, end; >> int flags = NO_EXEC_MAPPINGS; >> +#ifdef CONFIG_KFENCE >> + phys_addr_t kfence_pool = 0; >> +#endif >> u64 i; >> >> /* >> @@ -564,6 +568,12 @@ static void __init map_mem(pgd_t *pgdp) >> } >> #endif >> >> +#ifdef CONFIG_KFENCE >> + kfence_pool = kfence_alloc_pool(); >> + if (kfence_pool) >> + memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE); >> +#endif >> + >> /* map all the memory banks */ >> for_each_mem_range(i, &start, &end) { >> if (start >= end) >> @@ -608,6 +618,20 @@ static void __init map_mem(pgd_t *pgdp) >> } >> } >> #endif >> + >> + /* Kfence pool needs page-level mapping */ >> +#ifdef CONFIG_KFENCE >> + if (kfence_pool) { >> + __map_memblock(pgdp, kfence_pool, >> + kfence_pool + KFENCE_POOL_SIZE, >> + pgprot_tagged(PAGE_KERNEL), >> + NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); >> + memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); >> + /* kfence_pool really mapped now */ >> + kfence_set_pool(kfence_pool); >> + } >> +#endif >> + >> } >> >> void mark_rodata_ro(void) >> diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c >> index 79dd201..61156d0 100644 >> --- a/arch/arm64/mm/pageattr.c >> +++ b/arch/arm64/mm/pageattr.c >> @@ -22,12 +22,11 @@ bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED >> bool can_set_direct_map(void) >> { >> /* >> - * rodata_full, DEBUG_PAGEALLOC and KFENCE require linear map to be >> + * rodata_full and DEBUG_PAGEALLOC require linear map to be >> * mapped at page granularity, so that it is possible to >> * protect/unprotect single pages. >> */ >> - return (rodata_enabled && rodata_full) || debug_pagealloc_enabled() || >> - IS_ENABLED(CONFIG_KFENCE); >> + return (rodata_enabled && rodata_full) || debug_pagealloc_enabled(); >> } >> >> static int change_page_range(pte_t *ptep, unsigned long addr, void *data) >> diff --git a/include/linux/kfence.h b/include/linux/kfence.h >> index 726857a..0252e74 100644 >> --- a/include/linux/kfence.h >> +++ b/include/linux/kfence.h >> @@ -61,7 +61,12 @@ static __always_inline bool is_kfence_address(const void *addr) >> /** >> * kfence_alloc_pool() - allocate the KFENCE pool via memblock >> */ >> -void __init kfence_alloc_pool(void); >> +phys_addr_t __init kfence_alloc_pool(void); >> + >> +/** >> + * kfence_set_pool() - KFENCE pool mapped and can be used >> + */ >> +void __init kfence_set_pool(phys_addr_t addr); >> >> /** >> * kfence_init() - perform KFENCE initialization at boot time >> @@ -223,7 +228,8 @@ bool __kfence_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *sla >> #else /* CONFIG_KFENCE */ >> >> static inline bool is_kfence_address(const void *addr) { return false; } >> -static inline void kfence_alloc_pool(void) { } >> +static inline phys_addr_t kfence_alloc_pool(void) { return (phys_addr_t)NULL; } >> +static inline void kfence_set_pool(phys_addr_t addr) { } >> static inline void kfence_init(void) { } >> static inline void kfence_shutdown_cache(struct kmem_cache *s) { } >> static inline void *kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) { return NULL; } >> diff --git a/init/main.c b/init/main.c >> index 4425d17..9aaf217 100644 >> --- a/init/main.c >> +++ b/init/main.c >> @@ -839,7 +839,6 @@ static void __init mm_init(void) >> */ >> page_ext_init_flatmem(); >> init_mem_debugging_and_hardening(); >> - kfence_alloc_pool(); > > This breaks other architectures. Nice catch. Thanks! > >> report_meminit(); >> kmsan_init_shadow(); >> stack_depot_early_init(); >> diff --git a/mm/kfence/core.c b/mm/kfence/core.c >> index 5349c37..dd5cdd5 100644 >> --- a/mm/kfence/core.c >> +++ b/mm/kfence/core.c >> @@ -809,15 +809,25 @@ static void toggle_allocation_gate(struct work_struct *work) >> >> /* === Public interface ===================================================== */ >> >> -void __init kfence_alloc_pool(void) >> +phys_addr_t __init kfence_alloc_pool(void) >> { > > You could just return here: > > if (__kfence_pool) > return; /* Initialized earlier by arch init code. */ Yeah. > > ... and see my comments below. > >> + phys_addr_t kfence_pool; >> if (!kfence_sample_interval) >> - return; >> + return 0; >> >> - __kfence_pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); >> + kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); >> >> - if (!__kfence_pool) >> + if (!kfence_pool) { >> pr_err("failed to allocate pool\n"); >> + return 0; >> + } >> + >> + return kfence_pool; >> +} >> + >> +void __init kfence_set_pool(phys_addr_t addr) >> +{ >> + __kfence_pool = phys_to_virt(addr); >> } > > I would suggest leaving kfence_alloc_pool() to return nothing (with > the addition above), and just set __kfence_pool as before. > __kfence_pool itself is exported by include/linux/kfence.h, so if you > call kfence_alloc_pool() in arm64 earlier, you can access > __kfence_pool to get the allocated pool. Shall we add one new function like arm64_kfence_alloc_pool() ? The reason is linear mapping at that time not set up and we must alloc phys addr based on memblock. We can't use common kfence_alloc_pool().. > > Because at that point, KFENCE isn't yet running, that only happens > after kfence_init() much later. > > With these changes, you should be able to make arm64 work the way you > want, and not break other architectures where we don't need arch init > code to allocate the pool. > > Thanks, > -- Marco