respectively. For ARM the EFI stub is implemented in
arch/arm/boot/compressed/efi-header.S and
arch/arm/boot/compressed/efi-stub.c. EFI stub code that is shared
-between architectures is in drivers/firmware/efi/efi-stub-helper.c.
+between architectures is in drivers/firmware/efi/libstub.
For arm64, there is no compressed kernel support, so the Image itself
masquerades as a PE/COFF image and the EFI stub is linked into the
kernel. The arm64 EFI stub lives in arch/arm64/kernel/efi-entry.S
-and arch/arm64/kernel/efi-stub.c.
+and drivers/firmware/efi/libstub/arm64-stub.c.
By using the EFI boot stub it's possible to boot a Linux kernel
without the use of a conventional EFI boot loader, such as grub or
... unused hole ...
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
+ffffffef00000000 - ffffffff00000000 (=64 GB) EFI region mapping space
+... unused hole ...
ffffffff80000000 - ffffffffa0000000 (=512 MB) kernel text mapping, from phys 0
ffffffffa0000000 - ffffffffff5fffff (=1525 MB) module mapping space
ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
Current X86-64 implementations only support 40 bits of address space,
but we support up to 46 bits. This expands into MBZ space in the page tables.
-->trampoline_pgd:
-
-We map EFI runtime services in the aforementioned PGD in the virtual
-range of 64Gb (arbitrarily set, can be raised if needed)
-
-0xffffffef00000000 - 0xffffffff00000000
+We map EFI runtime services in the 'efi_pgd' PGD in a 64Gb large virtual
+memory window (this size is arbitrary, it can be raised later if needed).
+The mappings are not part of any other kernel PGD and are only available
+during EFI runtime calls.
-Andi Kleen, Jul 2004
#include <asm/fpu/api.h>
#include <asm/pgtable.h>
+#include <asm/tlb.h>
/*
* We map the EFI regions needed for runtime services non-contiguously,
#define efi_call_phys(f, args...) efi_call((f), args)
+/*
+ * Scratch space used for switching the pagetable in the EFI stub
+ */
+struct efi_scratch {
+ u64 r15;
+ u64 prev_cr3;
+ pgd_t *efi_pgt;
+ bool use_pgd;
+ u64 phys_stack;
+} __packed;
+
#define efi_call_virt(f, ...) \
({ \
efi_status_t __s; \
efi_sync_low_kernel_mappings(); \
preempt_disable(); \
__kernel_fpu_begin(); \
+ \
+ if (efi_scratch.use_pgd) { \
+ efi_scratch.prev_cr3 = read_cr3(); \
+ write_cr3((unsigned long)efi_scratch.efi_pgt); \
+ __flush_tlb_all(); \
+ } \
+ \
__s = efi_call((void *)efi.systab->runtime->f, __VA_ARGS__); \
+ \
+ if (efi_scratch.use_pgd) { \
+ write_cr3(efi_scratch.prev_cr3); \
+ __flush_tlb_all(); \
+ } \
+ \
__kernel_fpu_end(); \
preempt_enable(); \
__s; \
extern void __init efi_map_region(efi_memory_desc_t *md);
extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
extern void efi_sync_low_kernel_mappings(void);
+extern int __init efi_alloc_page_tables(void);
extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void __init old_map_region(efi_memory_desc_t *md);
__brk_limit = .;
}
+ . = ALIGN(PAGE_SIZE);
_end = .;
STABS_DEBUG
pte = pte_offset_kernel(pmd, start);
while (num_pages-- && start < end) {
-
- /* deal with the NX bit */
- if (!(pgprot_val(pgprot) & _PAGE_NX))
- cpa->pfn &= ~_PAGE_NX;
-
- set_pte(pte, pfn_pte(cpa->pfn >> PAGE_SHIFT, pgprot));
+ set_pte(pte, pfn_pte(cpa->pfn, pgprot));
start += PAGE_SIZE;
- cpa->pfn += PAGE_SIZE;
+ cpa->pfn++;
pte++;
}
}
pmd = pmd_offset(pud, start);
- set_pmd(pmd, __pmd(cpa->pfn | _PAGE_PSE |
+ set_pmd(pmd, __pmd(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
massage_pgprot(pmd_pgprot)));
start += PMD_SIZE;
- cpa->pfn += PMD_SIZE;
+ cpa->pfn += PMD_SIZE >> PAGE_SHIFT;
cur_pages += PMD_SIZE >> PAGE_SHIFT;
}
* Map everything starting from the Gb boundary, possibly with 1G pages
*/
while (end - start >= PUD_SIZE) {
- set_pud(pud, __pud(cpa->pfn | _PAGE_PSE |
+ set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
massage_pgprot(pud_pgprot)));
start += PUD_SIZE;
- cpa->pfn += PUD_SIZE;
+ cpa->pfn += PUD_SIZE >> PAGE_SHIFT;
cur_pages += PUD_SIZE >> PAGE_SHIFT;
pud++;
}
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/acpi.h>
void __init efi_bgrt_init(void)
{
acpi_status status;
- void __iomem *image;
- bool ioremapped = false;
+ void *image;
struct bmp_header bmp_header;
if (acpi_disabled)
return;
}
- image = efi_lookup_mapped_addr(bgrt_tab->image_address);
+ image = memremap(bgrt_tab->image_address, sizeof(bmp_header), MEMREMAP_WB);
if (!image) {
- image = early_ioremap(bgrt_tab->image_address,
- sizeof(bmp_header));
- ioremapped = true;
- if (!image) {
- pr_err("Ignoring BGRT: failed to map image header memory\n");
- return;
- }
+ pr_err("Ignoring BGRT: failed to map image header memory\n");
+ return;
}
- memcpy_fromio(&bmp_header, image, sizeof(bmp_header));
- if (ioremapped)
- early_iounmap(image, sizeof(bmp_header));
+ memcpy(&bmp_header, image, sizeof(bmp_header));
+ memunmap(image);
bgrt_image_size = bmp_header.size;
bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL | __GFP_NOWARN);
return;
}
- if (ioremapped) {
- image = early_ioremap(bgrt_tab->image_address,
- bmp_header.size);
- if (!image) {
- pr_err("Ignoring BGRT: failed to map image memory\n");
- kfree(bgrt_image);
- bgrt_image = NULL;
- return;
- }
+ image = memremap(bgrt_tab->image_address, bmp_header.size, MEMREMAP_WB);
+ if (!image) {
+ pr_err("Ignoring BGRT: failed to map image memory\n");
+ kfree(bgrt_image);
+ bgrt_image = NULL;
+ return;
}
- memcpy_fromio(bgrt_image, image, bgrt_image_size);
- if (ioremapped)
- early_iounmap(image, bmp_header.size);
+ memcpy(bgrt_image, image, bgrt_image_size);
+ memunmap(image);
}
{
#ifdef CONFIG_KEXEC_CORE
efi_memory_desc_t *md;
+ unsigned int num_pages;
void *p;
efi.systab = NULL;
return;
}
+ if (efi_alloc_page_tables()) {
+ pr_err("Failed to allocate EFI page tables\n");
+ clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+ return;
+ }
+
/*
* Map efi regions which were passed via setup_data. The virt_addr is a
* fixed addr which was used in first kernel of a kexec boot.
BUG_ON(!efi.systab);
+ num_pages = ALIGN(memmap.nr_map * memmap.desc_size, PAGE_SIZE);
+ num_pages >>= PAGE_SHIFT;
+
+ if (efi_setup_page_tables(memmap.phys_map, num_pages)) {
+ clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+ return;
+ }
+
efi_sync_low_kernel_mappings();
/*
* This function will switch the EFI runtime services to virtual mode.
* Essentially, we look through the EFI memmap and map every region that
* has the runtime attribute bit set in its memory descriptor into the
- * ->trampoline_pgd page table using a top-down VA allocation scheme.
+ * efi_pgd page table.
*
* The old method which used to update that memory descriptor with the
* virtual address obtained from ioremap() is still supported when the
*
* The new method does a pagetable switch in a preemption-safe manner
* so that we're in a different address space when calling a runtime
- * function. For function arguments passing we do copy the PGDs of the
- * kernel page table into ->trampoline_pgd prior to each call.
+ * function. For function arguments passing we do copy the PUDs of the
+ * kernel page table into efi_pgd prior to each call.
*
* Specially for kexec boot, efi runtime maps in previous kernel should
* be passed in via setup_data. In that case runtime ranges will be mapped
efi.systab = NULL;
+ if (efi_alloc_page_tables()) {
+ pr_err("Failed to allocate EFI page tables\n");
+ clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+ return;
+ }
+
efi_merge_regions();
new_memmap = efi_map_regions(&count, &pg_shift);
if (!new_memmap) {
efi_runtime_mkexec();
/*
- * We mapped the descriptor array into the EFI pagetable above but we're
- * not unmapping it here. Here's why:
- *
- * We're copying select PGDs from the kernel page table to the EFI page
- * table and when we do so and make changes to those PGDs like unmapping
- * stuff from them, those changes appear in the kernel page table and we
- * go boom.
- *
- * From setup_real_mode():
- *
- * ...
- * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
- *
- * In this particular case, our allocation is in PGD 0 of the EFI page
- * table but we've copied that PGD from PGD[272] of the EFI page table:
- *
- * pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
- *
- * where the direct memory mapping in kernel space is.
- *
- * new_memmap's VA comes from that direct mapping and thus clearing it,
- * it would get cleared in the kernel page table too.
+ * We mapped the descriptor array into the EFI pagetable above
+ * but we're not unmapping it here because if we're running in
+ * EFI mixed mode we need all of memory to be accessible when
+ * we pass parameters to the EFI runtime services in the
+ * thunking code.
*
* efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
*/
* say 0 - 3G.
*/
+int __init efi_alloc_page_tables(void)
+{
+ return 0;
+}
+
void efi_sync_low_kernel_mappings(void) {}
void __init efi_dump_pagetable(void) {}
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
*
*/
+#define pr_fmt(fmt) "efi: " fmt
+
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <asm/fixmap.h>
#include <asm/realmode.h>
#include <asm/time.h>
+#include <asm/pgalloc.h>
/*
* We allocate runtime services regions bottom-up, starting from -4G, i.e.
*/
static u64 efi_va = EFI_VA_START;
-/*
- * Scratch space used for switching the pagetable in the EFI stub
- */
-struct efi_scratch {
- u64 r15;
- u64 prev_cr3;
- pgd_t *efi_pgt;
- bool use_pgd;
- u64 phys_stack;
-} __packed;
+struct efi_scratch efi_scratch;
static void __init early_code_mapping_set_exec(int executable)
{
int pgd;
int n_pgds;
- if (!efi_enabled(EFI_OLD_MEMMAP))
- return NULL;
+ if (!efi_enabled(EFI_OLD_MEMMAP)) {
+ save_pgd = (pgd_t *)read_cr3();
+ write_cr3((unsigned long)efi_scratch.efi_pgt);
+ goto out;
+ }
early_code_mapping_set_exec(1);
vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
}
+out:
__flush_tlb_all();
return save_pgd;
int pgd_idx;
int nr_pgds;
- if (!save_pgd)
+ if (!efi_enabled(EFI_OLD_MEMMAP)) {
+ write_cr3((unsigned long)save_pgd);
+ __flush_tlb_all();
return;
+ }
nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
early_code_mapping_set_exec(0);
}
+static pgd_t *efi_pgd;
+
+/*
+ * We need our own copy of the higher levels of the page tables
+ * because we want to avoid inserting EFI region mappings (EFI_VA_END
+ * to EFI_VA_START) into the standard kernel page tables. Everything
+ * else can be shared, see efi_sync_low_kernel_mappings().
+ */
+int __init efi_alloc_page_tables(void)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ gfp_t gfp_mask;
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return 0;
+
+ gfp_mask = GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO;
+ efi_pgd = (pgd_t *)__get_free_page(gfp_mask);
+ if (!efi_pgd)
+ return -ENOMEM;
+
+ pgd = efi_pgd + pgd_index(EFI_VA_END);
+
+ pud = pud_alloc_one(NULL, 0);
+ if (!pud) {
+ free_page((unsigned long)efi_pgd);
+ return -ENOMEM;
+ }
+
+ pgd_populate(NULL, pgd, pud);
+
+ return 0;
+}
+
/*
* Add low kernel mappings for passing arguments to EFI functions.
*/
void efi_sync_low_kernel_mappings(void)
{
- unsigned num_pgds;
- pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+ unsigned num_entries;
+ pgd_t *pgd_k, *pgd_efi;
+ pud_t *pud_k, *pud_efi;
if (efi_enabled(EFI_OLD_MEMMAP))
return;
- num_pgds = pgd_index(MODULES_END - 1) - pgd_index(PAGE_OFFSET);
+ /*
+ * We can share all PGD entries apart from the one entry that
+ * covers the EFI runtime mapping space.
+ *
+ * Make sure the EFI runtime region mappings are guaranteed to
+ * only span a single PGD entry and that the entry also maps
+ * other important kernel regions.
+ */
+ BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
+ BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
+ (EFI_VA_END & PGDIR_MASK));
+
+ pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
+ pgd_k = pgd_offset_k(PAGE_OFFSET);
+
+ num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
+ memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
+
+ /*
+ * We share all the PUD entries apart from those that map the
+ * EFI regions. Copy around them.
+ */
+ BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
+ BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
+
+ pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
+ pud_efi = pud_offset(pgd_efi, 0);
- memcpy(pgd + pgd_index(PAGE_OFFSET),
- init_mm.pgd + pgd_index(PAGE_OFFSET),
- sizeof(pgd_t) * num_pgds);
+ pgd_k = pgd_offset_k(EFI_VA_END);
+ pud_k = pud_offset(pgd_k, 0);
+
+ num_entries = pud_index(EFI_VA_END);
+ memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
+
+ pud_efi = pud_offset(pgd_efi, EFI_VA_START);
+ pud_k = pud_offset(pgd_k, EFI_VA_START);
+
+ num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
+ memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
}
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
- unsigned long text;
+ unsigned long pfn, text;
+ efi_memory_desc_t *md;
struct page *page;
unsigned npages;
pgd_t *pgd;
if (efi_enabled(EFI_OLD_MEMMAP))
return 0;
- efi_scratch.efi_pgt = (pgd_t *)(unsigned long)real_mode_header->trampoline_pgd;
- pgd = __va(efi_scratch.efi_pgt);
+ efi_scratch.efi_pgt = (pgd_t *)__pa(efi_pgd);
+ pgd = efi_pgd;
/*
* It can happen that the physical address of new_memmap lands in memory
* and ident-map those pages containing the map before calling
* phys_efi_set_virtual_address_map().
*/
- if (kernel_map_pages_in_pgd(pgd, pa_memmap, pa_memmap, num_pages, _PAGE_NX)) {
+ pfn = pa_memmap >> PAGE_SHIFT;
+ if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX)) {
pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
return 1;
}
if (!IS_ENABLED(CONFIG_EFI_MIXED))
return 0;
+ /*
+ * Map all of RAM so that we can access arguments in the 1:1
+ * mapping when making EFI runtime calls.
+ */
+ for_each_efi_memory_desc(&memmap, md) {
+ if (md->type != EFI_CONVENTIONAL_MEMORY &&
+ md->type != EFI_LOADER_DATA &&
+ md->type != EFI_LOADER_CODE)
+ continue;
+
+ pfn = md->phys_addr >> PAGE_SHIFT;
+ npages = md->num_pages;
+
+ if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, npages, 0)) {
+ pr_err("Failed to map 1:1 memory\n");
+ return 1;
+ }
+ }
+
page = alloc_page(GFP_KERNEL|__GFP_DMA32);
if (!page)
panic("Unable to allocate EFI runtime stack < 4GB\n");
npages = (_end - _text) >> PAGE_SHIFT;
text = __pa(_text);
+ pfn = text >> PAGE_SHIFT;
- if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) {
+ if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, 0)) {
pr_err("Failed to map kernel text 1:1\n");
return 1;
}
void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
- pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
-
- kernel_unmap_pages_in_pgd(pgd, pa_memmap, num_pages);
+ kernel_unmap_pages_in_pgd(efi_pgd, pa_memmap, num_pages);
}
static void __init __map_region(efi_memory_desc_t *md, u64 va)
{
- pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
- unsigned long pf = 0;
+ unsigned long flags = 0;
+ unsigned long pfn;
+ pgd_t *pgd = efi_pgd;
if (!(md->attribute & EFI_MEMORY_WB))
- pf |= _PAGE_PCD;
+ flags |= _PAGE_PCD;
- if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
+ pfn = md->phys_addr >> PAGE_SHIFT;
+ if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
md->phys_addr, va);
}
void __init efi_dump_pagetable(void)
{
#ifdef CONFIG_EFI_PGT_DUMP
- pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
-
- ptdump_walk_pgd_level(NULL, pgd);
+ ptdump_walk_pgd_level(NULL, efi_pgd);
#endif
}
mov %rsi, %cr0; \
mov (%rsp), %rsp
- /* stolen from gcc */
- .macro FLUSH_TLB_ALL
- movq %r15, efi_scratch(%rip)
- movq %r14, efi_scratch+8(%rip)
- movq %cr4, %r15
- movq %r15, %r14
- andb $0x7f, %r14b
- movq %r14, %cr4
- movq %r15, %cr4
- movq efi_scratch+8(%rip), %r14
- movq efi_scratch(%rip), %r15
- .endm
-
- .macro SWITCH_PGT
- cmpb $0, efi_scratch+24(%rip)
- je 1f
- movq %r15, efi_scratch(%rip) # r15
- # save previous CR3
- movq %cr3, %r15
- movq %r15, efi_scratch+8(%rip) # prev_cr3
- movq efi_scratch+16(%rip), %r15 # EFI pgt
- movq %r15, %cr3
- 1:
- .endm
-
- .macro RESTORE_PGT
- cmpb $0, efi_scratch+24(%rip)
- je 2f
- movq efi_scratch+8(%rip), %r15
- movq %r15, %cr3
- movq efi_scratch(%rip), %r15
- FLUSH_TLB_ALL
- 2:
- .endm
-
ENTRY(efi_call)
SAVE_XMM
mov (%rsp), %rax
mov %r8, %r9
mov %rcx, %r8
mov %rsi, %rcx
- SWITCH_PGT
call *%rdi
- RESTORE_PGT
addq $48, %rsp
RESTORE_XMM
ret
ENDPROC(efi_call)
-
- .data
-ENTRY(efi_scratch)
- .fill 3,8,0
- .byte 0
- .quad 0
+#define pr_fmt(fmt) "efi: " fmt
+
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
* services.
*/
if (!efi_runtime_supported()) {
- pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
+ pr_info("Setup done, disabling due to 32/64-bit mismatch\n");
efi_unmap_memmap();
}
return end;
}
-/*
- * We can't ioremap data in EFI boot services RAM, because we've already mapped
- * it as RAM. So, look it up in the existing EFI memory map instead. Only
- * callable after efi_enter_virtual_mode and before efi_free_boot_services.
- */
-void __iomem *efi_lookup_mapped_addr(u64 phys_addr)
-{
- struct efi_memory_map *map;
- void *p;
- map = efi.memmap;
- if (!map)
- return NULL;
- if (WARN_ON(!map->map))
- return NULL;
- for (p = map->map; p < map->map_end; p += map->desc_size) {
- efi_memory_desc_t *md = p;
- u64 size = md->num_pages << EFI_PAGE_SHIFT;
- u64 end = md->phys_addr + size;
- if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
- md->type != EFI_BOOT_SERVICES_CODE &&
- md->type != EFI_BOOT_SERVICES_DATA)
- continue;
- if (!md->virt_addr)
- continue;
- if (phys_addr >= md->phys_addr && phys_addr < end) {
- phys_addr += md->virt_addr - md->phys_addr;
- return (__force void __iomem *)(unsigned long)phys_addr;
- }
- }
- return NULL;
-}
-
static __initdata efi_config_table_type_t common_tables[] = {
{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
static int esre_create_sysfs_entry(void *esre, int entry_num)
{
struct esre_entry *entry;
- char name[20];
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
- sprintf(name, "entry%d", entry_num);
-
entry->kobj.kset = esrt_kset;
if (esrt->fw_resource_version == 1) {
entry->esre.esre1 = esre;
rc = kobject_init_and_add(&entry->kobj, &esre1_ktype, NULL,
- "%s", name);
+ "entry%d", entry_num);
if (rc) {
kfree(entry);
return rc;