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The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: From: Fangyu Yu Crash kexec uses riscv_kexec_norelocate as a trampoline to jump into the crashkernel. Add a small helper to build dedicated 4KB page tables that map the trampoline page as executable. Content analysis details: (-17.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 RCVD_IN_VALIDITY_SAFE_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [115.124.30.124 listed in sa-accredit.habeas.com] 0.0 RCVD_IN_VALIDITY_CERTIFIED_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [115.124.30.124 listed in sa-trusted.bondedsender.org] 0.0 RCVD_IN_VALIDITY_RPBL_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [115.124.30.124 listed in bl.score.senderscore.com] -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [115.124.30.124 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -7.5 USER_IN_DEF_SPF_WL From: address is in the default SPF welcome-list -7.5 USER_IN_DEF_DKIM_WL From: address is in the default DKIM welcome-list -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines -0.5 ENV_AND_HDR_SPF_MATCH Env and Hdr From used in default SPF WL Match X-BeenThere: kvm-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kvm-riscv" Errors-To: kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Fangyu Yu Crash kexec uses riscv_kexec_norelocate as a trampoline to jump into the crashkernel. Add a small helper to build dedicated 4KB page tables that map the trampoline page as executable. Two mappings are installed: - VA(__kexec_tramp_text_start) -> PA(__kexec_tramp_text_start) - PA(__kexec_tramp_text_start) -> PA(__kexec_tramp_text_start) This allows the trampoline to run regardless of whether it is entered via its linked virtual address or its physical address. Signed-off-by: Fangyu Yu --- arch/riscv/kernel/machine_kexec.c | 103 +++++++++++++++++++++++++++++- 1 file changed, 102 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c index 2306ce3e5f22..4e522a64a614 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -18,6 +18,98 @@ #include #include +static pgd_t kexec_tramp_pgd[PTRS_PER_PGD] __aligned(PAGE_SIZE); +static p4d_t kexec_tramp_p4d[PTRS_PER_P4D] __aligned(PAGE_SIZE); +static pud_t kexec_tramp_pud[PTRS_PER_PUD] __aligned(PAGE_SIZE); +static pmd_t kexec_tramp_pmd[PTRS_PER_PMD] __aligned(PAGE_SIZE); +static pte_t kexec_tramp_pte[PTRS_PER_PTE] __aligned(PAGE_SIZE); +static p4d_t kexec_tramp_p4d2[PTRS_PER_P4D] __aligned(PAGE_SIZE); +static pud_t kexec_tramp_pud2[PTRS_PER_PUD] __aligned(PAGE_SIZE); +static pmd_t kexec_tramp_pmd2[PTRS_PER_PMD] __aligned(PAGE_SIZE); +static pte_t kexec_tramp_pte2[PTRS_PER_PTE] __aligned(PAGE_SIZE); + +static void riscv_kexec_build_tramp(unsigned long va, unsigned long pa) +{ + pgd_t *pgd; + pud_t *pud; + p4d_t *p4d; + pmd_t *pmd; + pte_t *pte; + int index; + + index = pgd_index(va); + pgd = (pgd_t *)kexec_tramp_pgd + index; + if (pgtable_l5_enabled) + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa_symbol(kexec_tramp_p4d)), + PAGE_TABLE)); + else + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa_symbol(kexec_tramp_pud)), + PAGE_TABLE)); + + if (pgtable_l5_enabled) { + index = p4d_index(va); + p4d = (p4d_t *)kexec_tramp_p4d + index; + if (pgtable_l4_enabled) + set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa_symbol(kexec_tramp_pud)), + PAGE_TABLE)); + else + set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa_symbol(kexec_tramp_pmd)), + PAGE_TABLE)); + } + + if (pgtable_l4_enabled) { + index = pud_index(va); + pud = (pud_t *)kexec_tramp_pud + index; + set_pud(pud, pfn_pud(PFN_DOWN(__pa_symbol(kexec_tramp_pmd)), PAGE_TABLE)); + } + + index = pmd_index(va); + if (pgtable_l4_enabled) + pmd = (pmd_t *)kexec_tramp_pmd + index; + else + pmd = (pmd_t *)kexec_tramp_pud + index; + set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa_symbol(kexec_tramp_pte)), PAGE_TABLE)); + + index = pte_index(va); + pte = (pte_t *)kexec_tramp_pte + index; + set_pte(pte, pfn_pte(PFN_DOWN(pa), PAGE_KERNEL_EXEC)); + + index = pgd_index(pa); + pgd = (pgd_t *)kexec_tramp_pgd + index; + if (pgtable_l5_enabled) + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa_symbol(kexec_tramp_p4d2)), PAGE_TABLE)); + else + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa_symbol(kexec_tramp_pud2)), PAGE_TABLE)); + + if (pgtable_l5_enabled) { + index = p4d_index(pa); + p4d = (p4d_t *)kexec_tramp_p4d2 + index; + if (pgtable_l4_enabled) + set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa_symbol(kexec_tramp_pud2)), + PAGE_TABLE)); + else + set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa_symbol(kexec_tramp_pmd2)), + PAGE_TABLE)); + } + + if (pgtable_l4_enabled) { + index = pud_index(pa); + pud = (pud_t *)kexec_tramp_pud2 + index; + set_pud(pud, pfn_pud(PFN_DOWN(__pa_symbol(kexec_tramp_pmd2)), PAGE_TABLE)); + } + + index = pmd_index(pa); + if (pgtable_l4_enabled) + pmd = (pmd_t *)kexec_tramp_pmd2 + index; + else + pmd = (pmd_t *)kexec_tramp_pud2 + index; + set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa_symbol(kexec_tramp_pte2)), PAGE_TABLE)); + + index = pte_index(pa); + pte = (pte_t *)kexec_tramp_pte2 + index; + set_pte(pte, pfn_pte(PFN_DOWN(pa), PAGE_KERNEL_EXEC)); +} + /* * machine_kexec_prepare - Initialize kexec * @@ -164,8 +256,17 @@ machine_kexec(struct kimage *image) if (image->type != KEXEC_TYPE_CRASH) kexec_method = control_code_buffer; - else + else { kexec_method = (riscv_kexec_method) &riscv_kexec_norelocate; + /* + * Build two 4KB identity-mapping page tables for the + * trampoline page: + * - VA(__kexec_tramp_text_start) -> PA(__kexec_tramp_text_start) + * - PA(__kexec_tramp_text_start) -> PA(__kexec_tramp_text_start) + */ + riscv_kexec_build_tramp((unsigned long)__kexec_tramp_text_start, + __pa_symbol(__kexec_tramp_text_start)); + } pr_notice("Will call new kernel at %08lx from hart id %lx\n", jump_addr, this_hart_id);