6.6.26-rc1 review

@@ -16,6 +16,14 @@ ssize_t of_modalias(const struct device_
 	ssize_t csize;
 	ssize_t tsize;
 
+	/*
+	 * Prevent a kernel oops in vsnprintf() -- it only allows passing a
+	 * NULL ptr when the length is also 0. Also filter out the negative
+	 * lengths...
+	 */
+	if ((len > 0 && !str) || len < 0)
+		return -EINVAL;
+
 	/* Name & Type */
 	/* %p eats all alphanum characters, so %c must be used here */
 	csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T',

@@ -55,28 +55,14 @@ static u64 mptcp_wnd_end(const struct mp
 	return READ_ONCE(msk->wnd_end);
 }
 
-static bool mptcp_is_tcpsk(struct sock *sk)
+static const struct proto_ops *mptcp_fallback_tcp_ops(const struct sock *sk)
 {
-	struct socket *sock = sk->sk_socket;
-
-	if (unlikely(sk->sk_prot == &tcp_prot)) {
-		/* we are being invoked after mptcp_accept() has
-		 * accepted a non-mp-capable flow: sk is a tcp_sk,
-		 * not an mptcp one.
-		 *
-		 * Hand the socket over to tcp so all further socket ops
-		 * bypass mptcp.
-		 */
-		WRITE_ONCE(sock->ops, &inet_stream_ops);
-		return true;
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
-	} else if (unlikely(sk->sk_prot == &tcpv6_prot)) {
-		WRITE_ONCE(sock->ops, &inet6_stream_ops);
-		return true;
+	if (sk->sk_prot == &tcpv6_prot)
+		return &inet6_stream_ops;
 #endif
-	}
-
-	return false;
+	WARN_ON_ONCE(sk->sk_prot != &tcp_prot);
+	return &inet_stream_ops;
 }
 
 static int __mptcp_socket_create(struct mptcp_sock *msk)

@@ -3328,44 +3314,6 @@ void mptcp_rcv_space_init(struct mptcp_s
 		msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT;
 }
 
-static struct sock *mptcp_accept(struct sock *ssk, int flags, int *err,
-				 bool kern)
-{
-	struct sock *newsk;
-
-	pr_debug("ssk=%p, listener=%p", ssk, mptcp_subflow_ctx(ssk));
-	newsk = inet_csk_accept(ssk, flags, err, kern);
-	if (!newsk)
-		return NULL;
-
-	pr_debug("newsk=%p, subflow is mptcp=%d", newsk, sk_is_mptcp(newsk));
-	if (sk_is_mptcp(newsk)) {
-		struct mptcp_subflow_context *subflow;
-		struct sock *new_mptcp_sock;
-
-		subflow = mptcp_subflow_ctx(newsk);
-		new_mptcp_sock = subflow->conn;
-
-		/* is_mptcp should be false if subflow->conn is missing, see
-		 * subflow_syn_recv_sock()
-		 */
-		if (WARN_ON_ONCE(!new_mptcp_sock)) {
-			tcp_sk(newsk)->is_mptcp = 0;
-			goto out;
-		}
-
-		newsk = new_mptcp_sock;
-		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
-	} else {
-		MPTCP_INC_STATS(sock_net(ssk),
-				MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
-	}
-
-out:
-	newsk->sk_kern_sock = kern;
-	return newsk;
-}
-
 void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags)
 {
 	struct mptcp_subflow_context *subflow, *tmp;

@@ -3802,7 +3750,6 @@ static struct proto mptcp_prot = {
 	.connect	= mptcp_connect,
 	.disconnect	= mptcp_disconnect,
 	.close		= mptcp_close,
-	.accept		= mptcp_accept,
 	.setsockopt	= mptcp_setsockopt,
 	.getsockopt	= mptcp_getsockopt,
 	.shutdown	= mptcp_shutdown,

@@ -3912,18 +3859,36 @@ static int mptcp_stream_accept(struct so
 	if (!ssk)
 		return -EINVAL;
 
-	newsk = mptcp_accept(ssk, flags, &err, kern);
+	pr_debug("ssk=%p, listener=%p", ssk, mptcp_subflow_ctx(ssk));
+	newsk = inet_csk_accept(ssk, flags, &err, kern);
 	if (!newsk)
 		return err;
 
-	lock_sock(newsk);
-
-	__inet_accept(sock, newsock, newsk);
-	if (!mptcp_is_tcpsk(newsock->sk)) {
-		struct mptcp_sock *msk = mptcp_sk(newsk);
+	pr_debug("newsk=%p, subflow is mptcp=%d", newsk, sk_is_mptcp(newsk));
+	if (sk_is_mptcp(newsk)) {
 		struct mptcp_subflow_context *subflow;
+		struct sock *new_mptcp_sock;
+
+		subflow = mptcp_subflow_ctx(newsk);
+		new_mptcp_sock = subflow->conn;
+
+		/* is_mptcp should be false if subflow->conn is missing, see
+		 * subflow_syn_recv_sock()
+		 */
+		if (WARN_ON_ONCE(!new_mptcp_sock)) {
+			tcp_sk(newsk)->is_mptcp = 0;
+			goto tcpfallback;
+		}
+
+		newsk = new_mptcp_sock;
+		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPCAPABLEPASSIVEACK);
+
+		newsk->sk_kern_sock = kern;
+		lock_sock(newsk);
+		__inet_accept(sock, newsock, newsk);
 
 		set_bit(SOCK_CUSTOM_SOCKOPT, &newsock->flags);
+		msk = mptcp_sk(newsk);
 		msk->in_accept_queue = 0;
 
 		/* set ssk->sk_socket of accept()ed flows to mptcp socket.

@@ -3945,6 +3910,21 @@ static int mptcp_stream_accept(struct so
 			if (unlikely(list_is_singular(&msk->conn_list)))
 				mptcp_set_state(newsk, TCP_CLOSE);
 		}
+	} else {
+		MPTCP_INC_STATS(sock_net(ssk),
+				MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
+tcpfallback:
+		newsk->sk_kern_sock = kern;
+		lock_sock(newsk);
+		__inet_accept(sock, newsock, newsk);
+		/* we are being invoked after accepting a non-mp-capable
+		 * flow: sk is a tcp_sk, not an mptcp one.
+		 *
+		 * Hand the socket over to tcp so all further socket ops
+		 * bypass mptcp.
+		 */
+		WRITE_ONCE(newsock->sk->sk_socket->ops,
+			   mptcp_fallback_tcp_ops(newsock->sk));
 	}
 	release_sock(newsk);
 

@@ -3911,8 +3911,6 @@ static int mptcp_stream_accept(struct so
 				mptcp_set_state(newsk, TCP_CLOSE);
 		}
 	} else {
-		MPTCP_INC_STATS(sock_net(ssk),
-				MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
 tcpfallback:
 		newsk->sk_kern_sock = kern;
 		lock_sock(newsk);

@@ -905,6 +905,8 @@ dispose_child:
 	return child;
 
 fallback:
+	if (fallback)
+		SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);
 	mptcp_subflow_drop_ctx(child);
 	return child;
 }

@@ -3065,6 +3065,9 @@ static void bpf_uprobe_multi_link_releas
 
 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
 	bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt);
+	if (umulti_link->task)
+		put_task_struct(umulti_link->task);
+	path_put(&umulti_link->path);
 }
 
 static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)

@@ -3072,9 +3075,6 @@ static void bpf_uprobe_multi_link_deallo
 	struct bpf_uprobe_multi_link *umulti_link;
 
 	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
-	if (umulti_link->task)
-		put_task_struct(umulti_link->task);
-	path_put(&umulti_link->path);
 	kvfree(umulti_link->uprobes);
 	kfree(umulti_link);
 }

@@ -1524,12 +1524,26 @@ struct bpf_link {
 	enum bpf_link_type type;
 	const struct bpf_link_ops *ops;
 	struct bpf_prog *prog;
-	struct work_struct work;
+	/* rcu is used before freeing, work can be used to schedule that
+	 * RCU-based freeing before that, so they never overlap
+	 */
+	union {
+		struct rcu_head rcu;
+		struct work_struct work;
+	};
 };
 
 struct bpf_link_ops {
 	void (*release)(struct bpf_link *link);
+	/* deallocate link resources callback, called without RCU grace period
+	 * waiting
+	 */
 	void (*dealloc)(struct bpf_link *link);
+	/* deallocate link resources callback, called after RCU grace period;
+	 * if underlying BPF program is sleepable we go through tasks trace
+	 * RCU GP and then "classic" RCU GP
+	 */
+	void (*dealloc_deferred)(struct bpf_link *link);
 	int (*detach)(struct bpf_link *link);
 	int (*update_prog)(struct bpf_link *link, struct bpf_prog *new_prog,
 			   struct bpf_prog *old_prog);

@@ -2866,17 +2866,46 @@ void bpf_link_inc(struct bpf_link *link)
 	atomic64_inc(&link->refcnt);
 }
 
+static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
+{
+	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
+
+	/* free bpf_link and its containing memory */
+	link->ops->dealloc_deferred(link);
+}
+
+static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
+{
+	if (rcu_trace_implies_rcu_gp())
+		bpf_link_defer_dealloc_rcu_gp(rcu);
+	else
+		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
+}
+
 /* bpf_link_free is guaranteed to be called from process context */
 static void bpf_link_free(struct bpf_link *link)
 {
+	bool sleepable = false;
+
 	bpf_link_free_id(link->id);
 	if (link->prog) {
+		sleepable = link->prog->aux->sleepable;
 		/* detach BPF program, clean up used resources */
 		link->ops->release(link);
 		bpf_prog_put(link->prog);
 	}
-	/* free bpf_link and its containing memory */
-	link->ops->dealloc(link);
+	if (link->ops->dealloc_deferred) {
+		/* schedule BPF link deallocation; if underlying BPF program
+		 * is sleepable, we need to first wait for RCU tasks trace
+		 * sync, then go through "classic" RCU grace period
+		 */
+		if (sleepable)
+			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
+		else
+			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
+	}
+	if (link->ops->dealloc)
+		link->ops->dealloc(link);
 }
 
 static void bpf_link_put_deferred(struct work_struct *work)

@@ -3381,7 +3410,7 @@ static int bpf_raw_tp_link_fill_link_inf
 
 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
 	.release = bpf_raw_tp_link_release,
-	.dealloc = bpf_raw_tp_link_dealloc,
+	.dealloc_deferred = bpf_raw_tp_link_dealloc,
 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
 };

@@ -2639,7 +2639,7 @@ static int bpf_kprobe_multi_link_fill_li
 
 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
 	.release = bpf_kprobe_multi_link_release,
-	.dealloc = bpf_kprobe_multi_link_dealloc,
+	.dealloc_deferred = bpf_kprobe_multi_link_dealloc,
 	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
 };
 

@@ -3081,7 +3081,7 @@ static void bpf_uprobe_multi_link_deallo
 
 static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
 	.release = bpf_uprobe_multi_link_release,
-	.dealloc = bpf_uprobe_multi_link_dealloc,
+	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,
 };
 
 static int uprobe_prog_run(struct bpf_uprobe *uprobe,

@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_INIT_H
 #define _ASM_X86_INIT_H
 
+#define __head	__section(".head.text")
+
 struct x86_mapping_info {
 	void *(*alloc_pgt_page)(void *); /* allocate buf for page table */
 	void *context;			 /* context for alloc_pgt_page */

@@ -41,6 +41,7 @@
 #include <asm/trapnr.h>
 #include <asm/sev.h>
 #include <asm/tdx.h>
+#include <asm/init.h>
 
 /*
  * Manage page tables very early on.

@@ -84,8 +85,6 @@ static struct desc_ptr startup_gdt_descr
 	.address = 0,
 };
 
-#define __head	__section(".head.text")
-
 static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
 {
 	return ptr - (void *)_text + (void *)physaddr;

@@ -24,6 +24,8 @@ static bool efi_noinitrd;
 static bool efi_nosoftreserve;
 static bool efi_disable_pci_dma = IS_ENABLED(CONFIG_EFI_DISABLE_PCI_DMA);
 
+int efi_mem_encrypt;
+
 bool __pure __efi_soft_reserve_enabled(void)
 {
 	return !efi_nosoftreserve;

@@ -75,6 +77,12 @@ efi_status_t efi_parse_options(char cons
 			efi_noinitrd = true;
 		} else if (IS_ENABLED(CONFIG_X86_64) && !strcmp(param, "no5lvl")) {
 			efi_no5lvl = true;
+		} else if (IS_ENABLED(CONFIG_ARCH_HAS_MEM_ENCRYPT) &&
+			   !strcmp(param, "mem_encrypt") && val) {
+			if (parse_option_str(val, "on"))
+				efi_mem_encrypt = 1;
+			else if (parse_option_str(val, "off"))
+				efi_mem_encrypt = -1;
 		} else if (!strcmp(param, "efi") && val) {
 			efi_nochunk = parse_option_str(val, "nochunk");
 			efi_novamap |= parse_option_str(val, "novamap");

@@ -37,8 +37,8 @@ extern bool efi_no5lvl;
 extern bool efi_nochunk;
 extern bool efi_nokaslr;
 extern int efi_loglevel;
+extern int efi_mem_encrypt;
 extern bool efi_novamap;
-
 extern const efi_system_table_t *efi_system_table;
 
 typedef union efi_dxe_services_table efi_dxe_services_table_t;

@@ -46,8 +46,8 @@ void __init sme_unmap_bootdata(char *rea
 void __init sme_early_init(void);
 void __init sev_setup_arch(void);
 
-void __init sme_encrypt_kernel(struct boot_params *bp);
-void __init sme_enable(struct boot_params *bp);
+void sme_encrypt_kernel(struct boot_params *bp);
+void sme_enable(struct boot_params *bp);
 
 int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
 int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);

@@ -81,8 +81,8 @@ static inline void __init sme_unmap_boot
 static inline void __init sme_early_init(void) { }
 static inline void __init sev_setup_arch(void) { }
 
-static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
-static inline void __init sme_enable(struct boot_params *bp) { }
+static inline void sme_encrypt_kernel(struct boot_params *bp) { }
+static inline void sme_enable(struct boot_params *bp) { }
 
 static inline void sev_es_init_vc_handling(void) { }
 

138 lines not on this page · raw message

@@ -116,6 +116,9 @@ static bool fault_in_kernel_space(unsign
 #undef __init
 #define __init
 
+#undef __head
+#define __head
+
 #define __BOOT_COMPRESSED
 
 /* Basic instruction decoding support needed */

@@ -199,15 +199,15 @@ static inline int pvalidate(unsigned lon
 struct snp_guest_request_ioctl;
 
 void setup_ghcb(void);
-void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
-					 unsigned long npages);
-void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
-					unsigned long npages);
+void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
+				  unsigned long npages);
+void early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
+				 unsigned long npages);
 void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
 void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
 void snp_set_wakeup_secondary_cpu(void);
 bool snp_init(struct boot_params *bp);
-void __init __noreturn snp_abort(void);
+void __noreturn snp_abort(void);
 void snp_dmi_setup(void);
 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
 void snp_accept_memory(phys_addr_t start, phys_addr_t end);

@@ -89,7 +89,8 @@ static bool __init sev_es_check_cpu_feat
 	return true;
 }
 
-static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason)
+static void __head __noreturn
+sev_es_terminate(unsigned int set, unsigned int reason)
 {
 	u64 val = GHCB_MSR_TERM_REQ;
 

@@ -326,13 +327,7 @@ static int sev_cpuid_hv(struct ghcb *ghc
  */
 static const struct snp_cpuid_table *snp_cpuid_get_table(void)
 {
-	void *ptr;
-
-	asm ("lea cpuid_table_copy(%%rip), %0"
-	     : "=r" (ptr)
-	     : "p" (&cpuid_table_copy));
-
-	return ptr;
+	return &RIP_REL_REF(cpuid_table_copy);
 }
 
 /*

@@ -391,7 +386,7 @@ static u32 snp_cpuid_calc_xsave_size(u64
 	return xsave_size;
 }
 
-static bool
+static bool __head
 snp_cpuid_get_validated_func(struct cpuid_leaf *leaf)
 {
 	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();

@@ -528,7 +523,8 @@ static int snp_cpuid_postprocess(struct
  * Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value
  * should be treated as fatal by caller.
  */
-static int snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)
+static int __head
+snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)
 {
 	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
 

@@ -570,7 +566,7 @@ static int snp_cpuid(struct ghcb *ghcb,
  * page yet, so it only supports the MSR based communication with the
  * hypervisor and only the CPUID exit-code.
  */
-void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
+void __head do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
 {
 	unsigned int subfn = lower_bits(regs->cx, 32);
 	unsigned int fn = lower_bits(regs->ax, 32);

@@ -1016,7 +1012,8 @@ struct cc_setup_data {
  * Search for a Confidential Computing blob passed in as a setup_data entry
  * via the Linux Boot Protocol.
  */
-static struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
+static __head
+struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
 {
 	struct cc_setup_data *sd = NULL;
 	struct setup_data *hdr;

@@ -1043,7 +1040,7 @@ static struct cc_blob_sev_info *find_cc_
  * mapping needs to be updated in sync with all the changes to virtual memory
  * layout and related mapping facilities throughout the boot process.
  */
-static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
+static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
 {
 	const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table;
 	int i;

@@ -26,6 +26,7 @@
 #include <linux/dmi.h>
 #include <uapi/linux/sev-guest.h>
 
+#include <asm/init.h>
 #include <asm/cpu_entry_area.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>

@@ -683,8 +684,9 @@ static u64 __init get_jump_table_addr(vo
 	return ret;
 }
 
-static void early_set_pages_state(unsigned long vaddr, unsigned long paddr,
-				  unsigned long npages, enum psc_op op)
+static void __head
+early_set_pages_state(unsigned long vaddr, unsigned long paddr,
+		      unsigned long npages, enum psc_op op)
 {
 	unsigned long paddr_end;
 	u64 val;

@@ -740,7 +742,7 @@ e_term:
 	sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
 }
 
-void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
+void __head early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
 					 unsigned long npages)
 {
 	/*

@@ -2045,7 +2047,7 @@ fail:
  *
  * Scan for the blob in that order.
  */
-static __init struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+static __head struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
 {
 	struct cc_blob_sev_info *cc_info;
 

@@ -2071,7 +2073,7 @@ found_cc_info:
 	return cc_info;
 }
 
-bool __init snp_init(struct boot_params *bp)
+bool __head snp_init(struct boot_params *bp)
 {
 	struct cc_blob_sev_info *cc_info;
 

@@ -2093,7 +2095,7 @@ bool __init snp_init(struct boot_params
 	return true;
 }
 
-void __init __noreturn snp_abort(void)
+void __head __noreturn snp_abort(void)
 {
 	sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
 }

@@ -330,6 +330,7 @@ static size_t parse_elf(void *output)
 	return ehdr.e_entry - LOAD_PHYSICAL_ADDR;
 }
 
+const unsigned long kernel_text_size = VO___start_rodata - VO__text;
 const unsigned long kernel_total_size = VO__end - VO__text;
 
 static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4);

@@ -81,6 +81,7 @@
 
 #ifndef __ASSEMBLY__
 extern unsigned int output_len;
+extern const unsigned long kernel_text_size;
 extern const unsigned long kernel_total_size;
 
 unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr,

@@ -238,6 +238,15 @@ efi_status_t efi_adjust_memory_range_pro
 	rounded_end = roundup(start + size, EFI_PAGE_SIZE);
 
 	if (memattr != NULL) {
+		status = efi_call_proto(memattr, set_memory_attributes,
+					rounded_start,
+					rounded_end - rounded_start,
+					EFI_MEMORY_RO);
+		if (status != EFI_SUCCESS) {
+			efi_warn("Failed to set EFI_MEMORY_RO attribute\n");
+			return status;
+		}
+
 		status = efi_call_proto(memattr, clear_memory_attributes,
 					rounded_start,
 					rounded_end - rounded_start,

@@ -816,7 +825,7 @@ static efi_status_t efi_decompress_kerne
 
 	*kernel_entry = addr + entry;
 
-	return efi_adjust_memory_range_protection(addr, kernel_total_size);
+	return efi_adjust_memory_range_protection(addr, kernel_text_size);
 }
 
 static void __noreturn enter_kernel(unsigned long kernel_addr,