^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2020 ARM Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/prctl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/swap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/swapops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/thread_info.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/uio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <asm/barrier.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <asm/cpufeature.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <asm/mte.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <asm/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <asm/sysreg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static bool report_fault_once = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static DEFINE_PER_CPU_READ_MOSTLY(u64, mte_tcf_preferred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #ifdef CONFIG_KASAN_HW_TAGS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) /* Whether the MTE asynchronous mode is enabled. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) DEFINE_STATIC_KEY_FALSE(mte_async_mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) EXPORT_SYMBOL_GPL(mte_async_mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) pte_t old_pte = READ_ONCE(*ptep);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) if (check_swap && is_swap_pte(old_pte)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) swp_entry_t entry = pte_to_swp_entry(old_pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) if (!non_swap_entry(entry) && mte_restore_tags(entry, page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) page_kasan_tag_reset(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * We need smp_wmb() in between setting the flags and clearing the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * tags because if another thread reads page->flags and builds a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * tagged address out of it, there is an actual dependency to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * memory access, but on the current thread we do not guarantee that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) * the new page->flags are visible before the tags were updated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) mte_clear_page_tags(page_address(page));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) void mte_sync_tags(pte_t *ptep, pte_t pte)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) struct page *page = pte_page(pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) long i, nr_pages = compound_nr(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) bool check_swap = nr_pages == 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) /* if PG_mte_tagged is set, tags have already been initialised */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) for (i = 0; i < nr_pages; i++, page++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if (!test_and_set_bit(PG_mte_tagged, &page->flags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) mte_sync_page_tags(page, ptep, check_swap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) int memcmp_pages(struct page *page1, struct page *page2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) char *addr1, *addr2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) addr1 = page_address(page1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) addr2 = page_address(page2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) ret = memcmp(addr1, addr2, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) if (!system_supports_mte() || ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * If the page content is identical but at least one of the pages is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * tagged, return non-zero to avoid KSM merging. If only one of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * pages is tagged, set_pte_at() may zero or change the tags of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * other page via mte_sync_tags().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (test_bit(PG_mte_tagged, &page1->flags) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) test_bit(PG_mte_tagged, &page2->flags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) return addr1 != addr2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) static inline void __mte_enable_kernel(const char *mode, unsigned long tcf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) /* Enable MTE Sync Mode for EL1. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, tcf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) isb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) pr_info_once("MTE: enabled in %s mode at EL1\n", mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) #ifdef CONFIG_KASAN_HW_TAGS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) void mte_enable_kernel_sync(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * Make sure we enter this function when no PE has set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * async mode previously.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) WARN_ONCE(system_uses_mte_async_mode(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) "MTE async mode enabled system wide!");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) __mte_enable_kernel("synchronous", SCTLR_ELx_TCF_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) void mte_enable_kernel_async(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) __mte_enable_kernel("asynchronous", SCTLR_ELx_TCF_ASYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * MTE async mode is set system wide by the first PE that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * executes this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * Note: If in future KASAN acquires a runtime switching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * mode in between sync and async, this strategy needs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * to be reviewed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) if (!system_uses_mte_async_mode())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) static_branch_enable(&mte_async_mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) void mte_set_report_once(bool state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) WRITE_ONCE(report_fault_once, state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) bool mte_report_once(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) return READ_ONCE(report_fault_once);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) #ifdef CONFIG_KASAN_HW_TAGS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) void mte_check_tfsr_el1(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) u64 tfsr_el1 = read_sysreg_s(SYS_TFSR_EL1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) if (unlikely(tfsr_el1 & SYS_TFSR_EL1_TF1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * Note: isb() is not required after this direct write
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * because there is no indirect read subsequent to it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * (per ARM DDI 0487F.c table D13-1).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) write_sysreg_s(0, SYS_TFSR_EL1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) kasan_report_async();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) static void mte_update_sctlr_user(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * This must be called with preemption disabled and can only be called
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * on the current or next task since the CPU must match where the thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * is going to run. The caller is responsible for calling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * update_sctlr_el1() later in the same preemption disabled block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) unsigned long sctlr = task->thread.sctlr_user;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) unsigned long mte_ctrl = task->thread.mte_ctrl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) unsigned long pref, resolved_mte_tcf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) pref = __this_cpu_read(mte_tcf_preferred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) resolved_mte_tcf = (mte_ctrl & pref) ? pref : mte_ctrl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) sctlr &= ~SCTLR_EL1_TCF0_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) if (resolved_mte_tcf & MTE_CTRL_TCF_ASYNC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) sctlr |= SCTLR_EL1_TCF0_ASYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) else if (resolved_mte_tcf & MTE_CTRL_TCF_SYNC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) sctlr |= SCTLR_EL1_TCF0_SYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) task->thread.sctlr_user = sctlr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) static void mte_update_gcr_excl(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) * SYS_GCR_EL1 will be set to current->thread.mte_ctrl value by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * mte_set_user_gcr() in kernel_exit, but only if KASAN is enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) if (kasan_hw_tags_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) write_sysreg_s(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) ((task->thread.mte_ctrl >> MTE_CTRL_GCR_USER_EXCL_SHIFT) &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) SYS_GCR_EL1_EXCL_MASK) | SYS_GCR_EL1_RRND,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) SYS_GCR_EL1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) void __init kasan_hw_tags_enable(struct alt_instr *alt, __le32 *origptr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) __le32 *updptr, int nr_inst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) BUG_ON(nr_inst != 1); /* Branch -> NOP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (kasan_hw_tags_enabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) *updptr = cpu_to_le32(aarch64_insn_gen_nop());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) void mte_thread_init_user(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) /* clear any pending asynchronous tag fault */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) dsb(ish);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) write_sysreg_s(0, SYS_TFSRE0_EL1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) clear_thread_flag(TIF_MTE_ASYNC_FAULT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) /* disable tag checking and reset tag generation mask */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) set_mte_ctrl(current, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) void mte_thread_switch(struct task_struct *next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) mte_update_sctlr_user(next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) mte_update_gcr_excl(next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * Check if an async tag exception occurred at EL1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) * Note: On the context switch path we rely on the dsb() present
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) * in __switch_to() to guarantee that the indirect writes to TFSR_EL1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) * are synchronized before this point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) isb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) mte_check_tfsr_el1();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) void mte_suspend_enter(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) * The barriers are required to guarantee that the indirect writes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) * to TFSR_EL1 are synchronized before we report the state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) dsb(nsh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) isb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) /* Report SYS_TFSR_EL1 before suspend entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) mte_check_tfsr_el1();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) long set_mte_ctrl(struct task_struct *task, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) u64 mte_ctrl = (~((arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT) &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) SYS_GCR_EL1_EXCL_MASK) << MTE_CTRL_GCR_USER_EXCL_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (arg & PR_MTE_TCF_ASYNC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) mte_ctrl |= MTE_CTRL_TCF_ASYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) if (arg & PR_MTE_TCF_SYNC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) mte_ctrl |= MTE_CTRL_TCF_SYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) task->thread.mte_ctrl = mte_ctrl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) if (task == current) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) mte_update_sctlr_user(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) mte_update_gcr_excl(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) update_sctlr_el1(task->thread.sctlr_user);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) long get_mte_ctrl(struct task_struct *task)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) unsigned long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) u64 mte_ctrl = task->thread.mte_ctrl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) u64 incl = (~mte_ctrl >> MTE_CTRL_GCR_USER_EXCL_SHIFT) &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) SYS_GCR_EL1_EXCL_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) ret = incl << PR_MTE_TAG_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) if (mte_ctrl & MTE_CTRL_TCF_ASYNC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) ret |= PR_MTE_TCF_ASYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) if (mte_ctrl & MTE_CTRL_TCF_SYNC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) ret |= PR_MTE_TCF_SYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * Access MTE tags in another process' address space as given in mm. Update
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * the number of tags copied. Return 0 if any tags copied, error otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) * Inspired by __access_remote_vm().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) static int __access_remote_tags(struct mm_struct *mm, unsigned long addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) struct iovec *kiov, unsigned int gup_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) struct vm_area_struct *vma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) void __user *buf = kiov->iov_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) size_t len = kiov->iov_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) int write = gup_flags & FOLL_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) if (!access_ok(buf, len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) if (mmap_read_lock_killable(mm))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) while (len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) unsigned long tags, offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) void *maddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) struct page *page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) ret = get_user_pages_remote(mm, addr, 1, gup_flags, &page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) &vma, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) if (ret <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) * Only copy tags if the page has been mapped as PROT_MTE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * (PG_mte_tagged set). Otherwise the tags are not valid and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * not accessible to user. Moreover, an mprotect(PROT_MTE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * would cause the existing tags to be cleared if the page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) * was never mapped with PROT_MTE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) if (!(vma->vm_flags & VM_MTE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) ret = -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) WARN_ON_ONCE(!test_bit(PG_mte_tagged, &page->flags));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) /* limit access to the end of the page */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) offset = offset_in_page(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) tags = min(len, (PAGE_SIZE - offset) / MTE_GRANULE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) maddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) if (write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) tags = mte_copy_tags_from_user(maddr + offset, buf, tags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) set_page_dirty_lock(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) tags = mte_copy_tags_to_user(buf, maddr + offset, tags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) /* error accessing the tracer's buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if (!tags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) len -= tags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) buf += tags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) addr += tags * MTE_GRANULE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) /* return an error if no tags copied */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) kiov->iov_len = buf - kiov->iov_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) if (!kiov->iov_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) /* check for error accessing the tracee's address space */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) if (ret <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) * Copy MTE tags in another process' address space at 'addr' to/from tracer's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) * iovec buffer. Return 0 on success. Inspired by ptrace_access_vm().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) static int access_remote_tags(struct task_struct *tsk, unsigned long addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) struct iovec *kiov, unsigned int gup_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) struct mm_struct *mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) mm = get_task_mm(tsk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) if (!mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) if (!tsk->ptrace || (current != tsk->parent) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) ((get_dumpable(mm) != SUID_DUMP_USER) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) !ptracer_capable(tsk, mm->user_ns))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) mmput(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) ret = __access_remote_tags(mm, addr, kiov, gup_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) mmput(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) int mte_ptrace_copy_tags(struct task_struct *child, long request,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) unsigned long addr, unsigned long data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) struct iovec kiov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) struct iovec __user *uiov = (void __user *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) unsigned int gup_flags = FOLL_FORCE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) if (get_user(kiov.iov_base, &uiov->iov_base) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) get_user(kiov.iov_len, &uiov->iov_len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) if (request == PTRACE_POKEMTETAGS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) gup_flags |= FOLL_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) /* align addr to the MTE tag granule */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) addr &= MTE_GRANULE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) ret = access_remote_tags(child, addr, &kiov, gup_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) ret = put_user(kiov.iov_len, &uiov->iov_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) static ssize_t mte_tcf_preferred_show(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) switch (per_cpu(mte_tcf_preferred, dev->id)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) case MTE_CTRL_TCF_ASYNC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) return sysfs_emit(buf, "async\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) case MTE_CTRL_TCF_SYNC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return sysfs_emit(buf, "sync\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) return sysfs_emit(buf, "???\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) static ssize_t mte_tcf_preferred_store(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) struct device_attribute *attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) const char *buf, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) u64 tcf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) if (sysfs_streq(buf, "async"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) tcf = MTE_CTRL_TCF_ASYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) else if (sysfs_streq(buf, "sync"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) tcf = MTE_CTRL_TCF_SYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) device_lock(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) per_cpu(mte_tcf_preferred, dev->id) = tcf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) device_unlock(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) static DEVICE_ATTR_RW(mte_tcf_preferred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) static int register_mte_tcf_preferred_sysctl(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) unsigned int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) if (!system_supports_mte())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) per_cpu(mte_tcf_preferred, cpu) = MTE_CTRL_TCF_ASYNC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) device_create_file(get_cpu_device(cpu),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) &dev_attr_mte_tcf_preferred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) subsys_initcall(register_mte_tcf_preferred_sysctl);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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