mm/pin_mem: refactor pin memory mem reserve and pid reserve code

euleros inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4REE5
CVE: NA

------------
1.Refactor pin memory mem reserve:
Move the memory reserve functions to pin_mem.c,
and avoid using unnecessary macros.

2.Refactor pid reserve code:
In oder to avoid using unnecessary compile macros in pid.c,
add stub functions for free_reserved_pid and reserve_pids.
Signed-off-by: NJingxian He <hejingxian@huawei.com>
Reviewed-by: Kefeng Wang<wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/kernel/setup.c

@@ -30,9 +30,7 @@
 #include <linux/psci.h>
 #include <linux/sched/task.h>
 #include <linux/mm.h>
-#ifdef CONFIG_PIN_MEMORY
 #include <linux/pin_mem.h>
-#endif
 
 #include <asm/acpi.h>
 #include <asm/fixmap.h>
@@ -297,11 +295,7 @@ static void __init request_standard_resources(void)
 			request_resource(res, &quick_kexec_res);
 #endif
 
-#ifdef CONFIG_PIN_MEMORY
-		if (pin_memory_resource.end && pin_memory_resource.start >= res->start &&
-			pin_memory_resource.end <= res->end)
-			request_resource(res, &pin_memory_resource);
-#endif
+		request_pin_mem_res(res);
 	}
 }
 

arch/arm64/mm/init.c

@@ -30,9 +30,7 @@
 #include <linux/crash_dump.h>
 #include <linux/hugetlb.h>
 #include <linux/acpi_iort.h>
-#ifdef CONFIG_PIN_MEMORY
 #include <linux/pin_mem.h>
-#endif
 
 #include <asm/boot.h>
 #include <asm/fixmap.h>
@@ -56,52 +54,6 @@
 s64 memstart_addr __ro_after_init = -1;
 EXPORT_SYMBOL(memstart_addr);
 
-#ifdef CONFIG_PIN_MEMORY
-struct resource pin_memory_resource = {
-	.name = "Pin memory",
-	.start = 0,
-	.end = 0,
-	.flags = IORESOURCE_MEM,
-	.desc = IORES_DESC_RESERVED
-};
-
-static void __init reserve_pin_memory_res(void)
-{
-	unsigned long long mem_start, mem_len;
-	int ret;
-
-	ret = parse_pin_memory(boot_command_line, memblock_phys_mem_size(),
-		&mem_len, &mem_start);
-	if (ret || !mem_len)
-		return;
-
-	mem_len = PAGE_ALIGN(mem_len);
-
-	if (!memblock_is_region_memory(mem_start, mem_len)) {
-		pr_warn("cannot reserve for pin memory: region is not memory!\n");
-		return;
-	}
-
-	if (memblock_is_region_reserved(mem_start, mem_len)) {
-		pr_warn("cannot reserve for pin memory: region overlaps reserved memory!\n");
-		return;
-	}
-
-	if (!IS_ALIGNED(mem_start, SZ_2M)) {
-		pr_warn("cannot reserve for pin memory: base address is not 2MB aligned\n");
-		return;
-	}
-
-	memblock_reserve(mem_start, mem_len);
-	pin_memory_resource.start = mem_start;
-	pin_memory_resource.end = mem_start + mem_len - 1;
-}
-#else
-static void __init reserve_pin_memory_res(void)
-{
-}
-#endif /* CONFIG_PIN_MEMORY */
-
 /*
  * If the corresponding config options are enabled, we create both ZONE_DMA
  * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory
@@ -729,11 +681,8 @@ void __init mem_init(void)
 	/* this will put all unused low memory onto the freelists */
 	memblock_free_all();
 
-#ifdef CONFIG_PIN_MEMORY
 	/* pre alloc the pages for pin memory */
-	init_reserve_page_map((unsigned long)pin_memory_resource.start,
-		(unsigned long)(pin_memory_resource.end - pin_memory_resource.start));
-#endif
+	init_reserve_page_map();
 
 	mem_init_print_info(NULL);
 

include/linux/pin_mem.h

@@ -83,17 +83,35 @@ extern int pagemap_get(struct mm_struct *mm, void *mem_walk,
 			unsigned long *pte_entry, unsigned int *count);
 
 extern int init_pagemap_read(void);
-/* reserve space for pin memory*/
-#ifdef CONFIG_ARM64
-extern struct resource pin_memory_resource;
-#endif
-extern void init_reserve_page_map(unsigned long map_addr, unsigned long map_size);
+
+extern void __init reserve_pin_memory_res(void);
+
+extern void request_pin_mem_res(struct resource *res);
+
+extern void init_reserve_page_map(void);
+
+#else
+
+static inline void __init reserve_pin_memory_res(void) {}
+
+static inline void request_pin_mem_res(struct resource *res) {}
+
+static inline void init_reserve_page_map(void) {}
+
+#endif /* CONFIG_PIN_MEMORY */
 
 #ifdef CONFIG_PID_RESERVE
-extern bool is_need_reserve_pids(void);
+
 extern void free_reserved_pid(struct idr *idr, int pid);
+
 extern void reserve_pids(struct idr *idr, int pid_max);
-#endif
 
-#endif /* CONFIG_PIN_MEMORY */
+#else
+
+static inline void free_reserved_pid(struct idr *idr, int pid) {}
+
+static inline void reserve_pids(struct idr *idr, int pid_max) {}
+
+#endif /* CONFIG_PID_RESERVE */
+
 #endif /* _LINUX_PIN_MEMORY_H */

kernel/pid.c

@@ -45,9 +45,7 @@
 #include <net/sock.h>
 #include <linux/kmemleak.h>
 #include <uapi/linux/pidfd.h>
-#ifdef CONFIG_PID_RESERVE
 #include <linux/pin_mem.h>
-#endif
 
 struct pid init_struct_pid = {
 	.count		= REFCOUNT_INIT(1),
@@ -212,9 +210,8 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,
 		spin_lock_irq(&pidmap_lock);
 
 		if (tid) {
-#ifdef CONFIG_PID_RESERVE
 			free_reserved_pid(&tmp->idr, tid);
-#endif
+
 			nr = idr_alloc(&tmp->idr, NULL, tid,
 				       tid + 1, GFP_ATOMIC);
 			/*
@@ -659,10 +656,9 @@ void __init pid_idr_init(void)
 
 	init_pid_ns.pid_cachep = KMEM_CACHE(pid,
 			SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT);
-#ifdef CONFIG_PID_RESERVE
-	if (is_need_reserve_pids())
-		reserve_pids(&init_pid_ns.idr, pid_max);
-#endif
+
+	reserve_pids(&init_pid_ns.idr, pid_max);
+
 	hdr = register_sysctl_paths(pid_kern_path, pid_ctl_table);
 	kmemleak_not_leak(hdr);
 }

mm/pin_mem.c

@@ -17,6 +17,7 @@
 #include <linux/ctype.h>
 #include <linux/highmem.h>
 #include <crypto/sha2.h>
+#include <linux/memblock.h>
 
 #define MAX_PIN_PID_NUM  128
 #define DEFAULT_REDIRECT_SPACE_SIZE  0x100000
@@ -1023,22 +1024,6 @@ vm_fault_t do_mem_remap(int pid, struct mm_struct *mm)
 }
 EXPORT_SYMBOL_GPL(do_mem_remap);
 
-#if defined(CONFIG_ARM64)
-void init_reserve_page_map(unsigned long map_addr, unsigned long map_size)
-{
-	void *addr;
-
-	if (!map_addr || !map_size)
-		return;
-	addr = phys_to_virt(map_addr);
-	init_page_map_info((struct pin_mem_dump_info *)addr, map_size);
-}
-#else
-void init_reserve_page_map(unsigned long map_addr, unsigned long map_size)
-{
-}
-#endif
-
 static void free_all_reserved_pages(void)
 {
 	unsigned int i, j, index, order;
@@ -1088,14 +1073,92 @@ void clear_pin_memory_record(void)
 }
 EXPORT_SYMBOL_GPL(clear_pin_memory_record);
 
-#ifdef CONFIG_PID_RESERVE
-struct idr *reserve_idr;
+static struct resource pin_memory_resource = {
+	.name = "Pin memory",
+	.start = 0,
+	.end = 0,
+	.flags = IORESOURCE_MEM,
+	.desc = IORES_DESC_RESERVED
+};
+
+static unsigned long long pin_mem_start;
+static unsigned long long pin_mem_len;
 
-/* test if there exist pin memory tasks */
-bool is_need_reserve_pids(void)
+static int __init parse_pin_memory(char *cmdline)
 {
-	return (pin_pid_num > 0);
+	char *cur = cmdline;
+
+	pin_mem_len = memparse(cmdline, &cur);
+	if (cmdline == cur) {
+		pr_warn("crashkernel: memory value expected\n");
+		return -EINVAL;
+	}
+
+	if (*cur == '@')
+		pin_mem_start = memparse(cur+1, &cur);
+	else if (*cur != ' ' && *cur != '\0') {
+		pr_warn("pinmem: unrecognized char: %c\n", *cur);
+		return -EINVAL;
+	}
+
+	return 0;
 }
+early_param("pinmemory", parse_pin_memory);
+
+void __init reserve_pin_memory_res(void)
+{
+	unsigned long long mem_start = pin_mem_start;
+	unsigned long long mem_len = pin_mem_len;
+
+	if (!pin_mem_len)
+		return;
+
+	mem_len = PAGE_ALIGN(mem_len);
+
+	if (!memblock_is_region_memory(mem_start, mem_len)) {
+		pr_warn("cannot reserve for pin memory: region is not memory!\n");
+		return;
+	}
+
+	if (memblock_is_region_reserved(mem_start, mem_len)) {
+		pr_warn("cannot reserve for pin memory: region overlaps reserved memory!\n");
+		return;
+	}
+
+	memblock_reserve(mem_start, mem_len);
+	pr_debug("pin memory resource reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
+		mem_start, mem_start + mem_len, mem_len >> 20);
+
+	pin_memory_resource.start = mem_start;
+	pin_memory_resource.end = mem_start + mem_len - 1;
+}
+
+void request_pin_mem_res(struct resource *res)
+{
+	if (pin_memory_resource.end &&
+		pin_memory_resource.start >= res->start &&
+		pin_memory_resource.end <= res->end)
+		request_resource(res, &pin_memory_resource);
+}
+
+void init_reserve_page_map(void)
+{
+	void *addr;
+	unsigned long map_addr, map_size;
+
+	map_addr = (unsigned long)pin_memory_resource.start;
+	map_size = (unsigned long)(pin_memory_resource.end - pin_memory_resource.start + 1);
+	if (!map_addr || !map_size)
+		return;
+
+	addr = phys_to_virt(map_addr);
+	init_page_map_info((struct pin_mem_dump_info *)addr, map_size);
+}
+
+#endif /* CONFIG_PIN_MEMORY */
+
+#ifdef CONFIG_PID_RESERVE
+struct idr *reserve_idr;
 
 void free_reserved_pid(struct idr *idr, int pid)
 {
@@ -1121,8 +1184,9 @@ void reserve_pids(struct idr *idr, int pid_max)
 	unsigned int index;
 	struct page_map_info *pmi;
 
-	if (!max_pin_pid_num)
+	if (!pin_pid_num || !max_pin_pid_num)
 		return;
+
 	reserve_idr = idr;
 	for (index = 0; index < pin_pid_num; index++) {
 		pmi = &(user_space_reserve_start[index]);
@@ -1137,6 +1201,6 @@ void reserve_pids(struct idr *idr, int pid_max)
 		}
 	}
 }
+
 #endif /* CONFIG_PID_RESERVE */
 
-#endif /* CONFIG_PIN_MEMORY */