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-rw-r--r--kernel/kexec_file.c145
1 files changed, 85 insertions, 60 deletions
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 037c321c5618..b56a558e406d 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -19,6 +19,7 @@
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/fs.h>
+#include <linux/ima.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <linux/syscalls.h>
@@ -132,6 +133,9 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
return ret;
image->kernel_buf_len = size;
+ /* IMA needs to pass the measurement list to the next kernel. */
+ ima_add_kexec_buffer(image);
+
/* Call arch image probe handlers */
ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
image->kernel_buf_len);
@@ -428,25 +432,65 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
return locate_mem_hole_bottom_up(start, end, kbuf);
}
-/*
- * Helper function for placing a buffer in a kexec segment. This assumes
- * that kexec_mutex is held.
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @kbuf: Context info for the search. Also passed to @func.
+ * @func: Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+ int (*func)(u64, u64, void *))
+{
+ if (kbuf->image->type == KEXEC_TYPE_CRASH)
+ return walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+ crashk_res.start, crashk_res.end,
+ kbuf, func);
+ else
+ return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
+/**
+ * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
+ * @kbuf: Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+ int ret;
+
+ ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
+
+ return ret == 1 ? 0 : -EADDRNOTAVAIL;
+}
+
+/**
+ * kexec_add_buffer - place a buffer in a kexec segment
+ * @kbuf: Buffer contents and memory parameters.
+ *
+ * This function assumes that kexec_mutex is held.
+ * On successful return, @kbuf->mem will have the physical address of
+ * the buffer in memory.
+ *
+ * Return: 0 on success, negative errno on error.
*/
-int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
- unsigned long memsz, unsigned long buf_align,
- unsigned long buf_min, unsigned long buf_max,
- bool top_down, unsigned long *load_addr)
+int kexec_add_buffer(struct kexec_buf *kbuf)
{
struct kexec_segment *ksegment;
- struct kexec_buf buf, *kbuf;
int ret;
/* Currently adding segment this way is allowed only in file mode */
- if (!image->file_mode)
+ if (!kbuf->image->file_mode)
return -EINVAL;
- if (image->nr_segments >= KEXEC_SEGMENT_MAX)
+ if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
return -EINVAL;
/*
@@ -456,45 +500,27 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
* logic goes through list of segments to make sure there are
* no destination overlaps.
*/
- if (!list_empty(&image->control_pages)) {
+ if (!list_empty(&kbuf->image->control_pages)) {
WARN_ON(1);
return -EINVAL;
}
- memset(&buf, 0, sizeof(struct kexec_buf));
- kbuf = &buf;
- kbuf->image = image;
- kbuf->buffer = buffer;
- kbuf->bufsz = bufsz;
-
- kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
- kbuf->buf_align = max(buf_align, PAGE_SIZE);
- kbuf->buf_min = buf_min;
- kbuf->buf_max = buf_max;
- kbuf->top_down = top_down;
+ /* Ensure minimum alignment needed for segments. */
+ kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
+ kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
/* Walk the RAM ranges and allocate a suitable range for the buffer */
- if (image->type == KEXEC_TYPE_CRASH)
- ret = walk_iomem_res_desc(crashk_res.desc,
- IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
- crashk_res.start, crashk_res.end, kbuf,
- locate_mem_hole_callback);
- else
- ret = walk_system_ram_res(0, -1, kbuf,
- locate_mem_hole_callback);
- if (ret != 1) {
- /* A suitable memory range could not be found for buffer */
- return -EADDRNOTAVAIL;
- }
+ ret = kexec_locate_mem_hole(kbuf);
+ if (ret)
+ return ret;
/* Found a suitable memory range */
- ksegment = &image->segment[image->nr_segments];
+ ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
ksegment->kbuf = kbuf->buffer;
ksegment->bufsz = kbuf->bufsz;
ksegment->mem = kbuf->mem;
ksegment->memsz = kbuf->memsz;
- image->nr_segments++;
- *load_addr = ksegment->mem;
+ kbuf->image->nr_segments++;
return 0;
}
@@ -616,13 +642,15 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
unsigned long max, int top_down)
{
struct purgatory_info *pi = &image->purgatory_info;
- unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
- unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
+ unsigned long align, bss_align, bss_sz, bss_pad;
+ unsigned long entry, load_addr, curr_load_addr, bss_addr, offset;
unsigned char *buf_addr, *src;
int i, ret = 0, entry_sidx = -1;
const Elf_Shdr *sechdrs_c;
Elf_Shdr *sechdrs = NULL;
- void *purgatory_buf = NULL;
+ struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1,
+ .buf_min = min, .buf_max = max,
+ .top_down = top_down };
/*
* sechdrs_c points to section headers in purgatory and are read
@@ -688,9 +716,7 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
}
/* Determine how much memory is needed to load relocatable object. */
- buf_align = 1;
bss_align = 1;
- buf_sz = 0;
bss_sz = 0;
for (i = 0; i < pi->ehdr->e_shnum; i++) {
@@ -699,10 +725,10 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
align = sechdrs[i].sh_addralign;
if (sechdrs[i].sh_type != SHT_NOBITS) {
- if (buf_align < align)
- buf_align = align;
- buf_sz = ALIGN(buf_sz, align);
- buf_sz += sechdrs[i].sh_size;
+ if (kbuf.buf_align < align)
+ kbuf.buf_align = align;
+ kbuf.bufsz = ALIGN(kbuf.bufsz, align);
+ kbuf.bufsz += sechdrs[i].sh_size;
} else {
/* bss section */
if (bss_align < align)
@@ -714,32 +740,31 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
/* Determine the bss padding required to align bss properly */
bss_pad = 0;
- if (buf_sz & (bss_align - 1))
- bss_pad = bss_align - (buf_sz & (bss_align - 1));
+ if (kbuf.bufsz & (bss_align - 1))
+ bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1));
- memsz = buf_sz + bss_pad + bss_sz;
+ kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz;
/* Allocate buffer for purgatory */
- purgatory_buf = vzalloc(buf_sz);
- if (!purgatory_buf) {
+ kbuf.buffer = vzalloc(kbuf.bufsz);
+ if (!kbuf.buffer) {
ret = -ENOMEM;
goto out;
}
- if (buf_align < bss_align)
- buf_align = bss_align;
+ if (kbuf.buf_align < bss_align)
+ kbuf.buf_align = bss_align;
/* Add buffer to segment list */
- ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
- buf_align, min, max, top_down,
- &pi->purgatory_load_addr);
+ ret = kexec_add_buffer(&kbuf);
if (ret)
goto out;
+ pi->purgatory_load_addr = kbuf.mem;
/* Load SHF_ALLOC sections */
- buf_addr = purgatory_buf;
+ buf_addr = kbuf.buffer;
load_addr = curr_load_addr = pi->purgatory_load_addr;
- bss_addr = load_addr + buf_sz + bss_pad;
+ bss_addr = load_addr + kbuf.bufsz + bss_pad;
for (i = 0; i < pi->ehdr->e_shnum; i++) {
if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -785,11 +810,11 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
* Used later to identify which section is purgatory and skip it
* from checksumming.
*/
- pi->purgatory_buf = purgatory_buf;
+ pi->purgatory_buf = kbuf.buffer;
return ret;
out:
vfree(sechdrs);
- vfree(purgatory_buf);
+ vfree(kbuf.buffer);
return ret;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 12:39:50 +0100