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Message-Id: <20180306102303.9063-8-takahiro.akashi@linaro.org>
Date: Tue, 6 Mar 2018 19:23:03 +0900
From: AKASHI Takahiro <takahiro.akashi@...aro.org>
To: dyoung@...hat.com, vgoyal@...hat.com, bhe@...hat.com,
mpe@...erman.id.au, bauerman@...ux.vnet.ibm.com,
prudo@...ux.vnet.ibm.com
Cc: kexec@...ts.infradead.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, linux-s390@...r.kernel.org,
AKASHI Takahiro <takahiro.akashi@...aro.org>
Subject: [PATCH v2 7/7] kexec_file, x86: move re-factored code to generic side
In the previous patches, commonly-used routines, exclude_mem_range() and
prepare_elf64_headers(), were carved out. Now place them in kexec common
code. A prefix "crash_" is given to each of their names to avoid possible
name collisions.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@...aro.org>
Cc: Dave Young <dyoung@...hat.com>
Cc: Vivek Goyal <vgoyal@...hat.com>
Cc: Baoquan He <bhe@...hat.com>
---
arch/x86/kernel/crash.c | 195 ++----------------------------------------------
include/linux/kexec.h | 19 +++++
kernel/kexec_file.c | 175 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 201 insertions(+), 188 deletions(-)
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 24de3f13f40c..a52671487ff2 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -38,19 +38,6 @@
#include <asm/virtext.h>
#include <asm/intel_pt.h>
-/* Alignment required for elf header segment */
-#define ELF_CORE_HEADER_ALIGN 4096
-
-struct crash_mem_range {
- u64 start, end;
-};
-
-struct crash_mem {
- unsigned int max_nr_ranges;
- unsigned int nr_ranges;
- struct crash_mem_range ranges[0];
-};
-
/* Used while preparing memory map entries for second kernel */
struct crash_memmap_data {
struct boot_params *params;
@@ -226,77 +213,6 @@ static struct crash_mem *fill_up_crash_elf_data(void)
return cmem;
}
-static int exclude_mem_range(struct crash_mem *mem,
- unsigned long long mstart, unsigned long long mend)
-{
- int i, j;
- unsigned long long start, end;
- struct crash_mem_range temp_range = {0, 0};
-
- for (i = 0; i < mem->nr_ranges; i++) {
- start = mem->ranges[i].start;
- end = mem->ranges[i].end;
-
- if (mstart > end || mend < start)
- continue;
-
- /* Truncate any area outside of range */
- if (mstart < start)
- mstart = start;
- if (mend > end)
- mend = end;
-
- /* Found completely overlapping range */
- if (mstart == start && mend == end) {
- mem->ranges[i].start = 0;
- mem->ranges[i].end = 0;
- if (i < mem->nr_ranges - 1) {
- /* Shift rest of the ranges to left */
- for (j = i; j < mem->nr_ranges - 1; j++) {
- mem->ranges[j].start =
- mem->ranges[j+1].start;
- mem->ranges[j].end =
- mem->ranges[j+1].end;
- }
- }
- mem->nr_ranges--;
- return 0;
- }
-
- if (mstart > start && mend < end) {
- /* Split original range */
- mem->ranges[i].end = mstart - 1;
- temp_range.start = mend + 1;
- temp_range.end = end;
- } else if (mstart != start)
- mem->ranges[i].end = mstart - 1;
- else
- mem->ranges[i].start = mend + 1;
- break;
- }
-
- /* If a split happend, add the split to array */
- if (!temp_range.end)
- return 0;
-
- /* Split happened */
- if (i == mem->max_nr_ranges - 1)
- return -ENOMEM;
-
- /* Location where new range should go */
- j = i + 1;
- if (j < mem->nr_ranges) {
- /* Move over all ranges one slot towards the end */
- for (i = mem->nr_ranges - 1; i >= j; i--)
- mem->ranges[i + 1] = mem->ranges[i];
- }
-
- mem->ranges[j].start = temp_range.start;
- mem->ranges[j].end = temp_range.end;
- mem->nr_ranges++;
- return 0;
-}
-
/*
* Look for any unwanted ranges between mstart, mend and remove them. This
* might lead to split and split ranges are put in cmem->ranges[] array
@@ -306,12 +222,13 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem)
int ret = 0;
/* Exclude crashkernel region */
- ret = exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+ ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
if (ret)
return ret;
if (crashk_low_res.end) {
- ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
+ crashk_low_res.end);
if (ret)
return ret;
}
@@ -330,105 +247,6 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
return 0;
}
-static int prepare_elf64_headers(struct crash_mem *cmem, bool kernel_map,
- void **addr, unsigned long *sz)
-{
- Elf64_Ehdr *ehdr;
- Elf64_Phdr *phdr;
- unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
- unsigned char *buf;
- unsigned int cpu, i;
- unsigned long long notes_addr;
- unsigned long mstart, mend;
-
- /* extra phdr for vmcoreinfo elf note */
- nr_phdr = nr_cpus + 1;
- nr_phdr += cmem->nr_ranges;
-
- /*
- * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
- * area on x86_64 (ffffffff80000000 - ffffffffa0000000).
- * I think this is required by tools like gdb. So same physical
- * memory will be mapped in two elf headers. One will contain kernel
- * text virtual addresses and other will have __va(physical) addresses.
- */
-
- nr_phdr++;
- elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
- elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
-
- buf = vzalloc(elf_sz);
- if (!buf)
- return -ENOMEM;
-
- ehdr = (Elf64_Ehdr *)buf;
- phdr = (Elf64_Phdr *)(ehdr + 1);
- memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
- ehdr->e_ident[EI_CLASS] = ELFCLASS64;
- ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
- ehdr->e_ident[EI_VERSION] = EV_CURRENT;
- ehdr->e_ident[EI_OSABI] = ELF_OSABI;
- memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
- ehdr->e_type = ET_CORE;
- ehdr->e_machine = ELF_ARCH;
- ehdr->e_version = EV_CURRENT;
- ehdr->e_phoff = sizeof(Elf64_Ehdr);
- ehdr->e_ehsize = sizeof(Elf64_Ehdr);
- ehdr->e_phentsize = sizeof(Elf64_Phdr);
-
- /* Prepare one phdr of type PT_NOTE for each present cpu */
- for_each_present_cpu(cpu) {
- phdr->p_type = PT_NOTE;
- notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
- phdr->p_offset = phdr->p_paddr = notes_addr;
- phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
- (ehdr->e_phnum)++;
- phdr++;
- }
-
- /* Prepare one PT_NOTE header for vmcoreinfo */
- phdr->p_type = PT_NOTE;
- phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
- phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
- (ehdr->e_phnum)++;
- phdr++;
-
- /* Prepare PT_LOAD type program header for kernel text region */
- if (kernel_map) {
- phdr->p_type = PT_LOAD;
- phdr->p_flags = PF_R|PF_W|PF_X;
- phdr->p_vaddr = (Elf64_Addr)_text;
- phdr->p_filesz = phdr->p_memsz = _end - _text;
- phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
- ehdr->e_phnum++;
- phdr++;
- }
-
- /* Go through all the ranges in cmem->ranges[] and prepare phdr */
- for (i = 0; i < cmem->nr_ranges; i++) {
- mstart = cmem->ranges[i].start;
- mend = cmem->ranges[i].end;
-
- phdr->p_type = PT_LOAD;
- phdr->p_flags = PF_R|PF_W|PF_X;
- phdr->p_offset = mstart;
-
- phdr->p_paddr = mstart;
- phdr->p_vaddr = (unsigned long long) __va(mstart);
- phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
- phdr->p_align = 0;
- ehdr->e_phnum++;
- phdr++;
- pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
- phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
- ehdr->e_phnum, phdr->p_offset);
- }
-
- *addr = buf;
- *sz = elf_sz;
- return 0;
-}
-
/* Prepare elf headers. Return addr and size */
static int prepare_elf_headers(struct kimage *image, void **addr,
unsigned long *sz)
@@ -453,7 +271,8 @@ static int prepare_elf_headers(struct kimage *image, void **addr,
goto out;
/* By default prepare 64bit headers */
- ret = prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
+ ret = crash_prepare_elf64_headers(cmem,
+ IS_ENABLED(CONFIG_X86_64), addr, sz);
if (ret)
goto out;
@@ -517,14 +336,14 @@ static int memmap_exclude_ranges(struct kimage *image, struct crash_mem *cmem,
/* Exclude Backup region */
start = image->arch.backup_load_addr;
end = start + image->arch.backup_src_sz - 1;
- ret = exclude_mem_range(cmem, start, end);
+ ret = crash_exclude_mem_range(cmem, start, end);
if (ret)
return ret;
/* Exclude elf header region */
start = image->arch.elf_load_addr;
end = start + image->arch.elf_headers_sz - 1;
- return exclude_mem_range(cmem, start, end);
+ return crash_exclude_mem_range(cmem, start, end);
}
/* Prepare memory map for crash dump kernel */
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 4ed18cc718fc..85609221cd80 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -168,6 +168,25 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
int (*func)(struct resource *, void *));
extern int kexec_add_buffer(struct kexec_buf *kbuf);
int kexec_locate_mem_hole(struct kexec_buf *kbuf);
+
+/* Alignment required for elf header segment */
+#define ELF_CORE_HEADER_ALIGN 4096
+
+struct crash_mem_range {
+ u64 start, end;
+};
+
+struct crash_mem {
+ unsigned int max_nr_ranges;
+ unsigned int nr_ranges;
+ struct crash_mem_range ranges[0];
+};
+
+extern int crash_exclude_mem_range(struct crash_mem *mem,
+ unsigned long long mstart,
+ unsigned long long mend);
+extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
+ void **addr, unsigned long *sz);
#endif /* CONFIG_KEXEC_FILE */
struct kimage {
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 6a62c5ef8a07..7d38eb578116 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -22,6 +22,11 @@
#include <linux/ima.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/vmalloc.h>
#include "kexec_internal.h"
@@ -1079,3 +1084,173 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
return 0;
}
#endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
+
+int crash_exclude_mem_range(struct crash_mem *mem,
+ unsigned long long mstart, unsigned long long mend)
+{
+ int i, j;
+ unsigned long long start, end;
+ struct crash_mem_range temp_range = {0, 0};
+
+ for (i = 0; i < mem->nr_ranges; i++) {
+ start = mem->ranges[i].start;
+ end = mem->ranges[i].end;
+
+ if (mstart > end || mend < start)
+ continue;
+
+ /* Truncate any area outside of range */
+ if (mstart < start)
+ mstart = start;
+ if (mend > end)
+ mend = end;
+
+ /* Found completely overlapping range */
+ if (mstart == start && mend == end) {
+ mem->ranges[i].start = 0;
+ mem->ranges[i].end = 0;
+ if (i < mem->nr_ranges - 1) {
+ /* Shift rest of the ranges to left */
+ for (j = i; j < mem->nr_ranges - 1; j++) {
+ mem->ranges[j].start =
+ mem->ranges[j+1].start;
+ mem->ranges[j].end =
+ mem->ranges[j+1].end;
+ }
+ }
+ mem->nr_ranges--;
+ return 0;
+ }
+
+ if (mstart > start && mend < end) {
+ /* Split original range */
+ mem->ranges[i].end = mstart - 1;
+ temp_range.start = mend + 1;
+ temp_range.end = end;
+ } else if (mstart != start)
+ mem->ranges[i].end = mstart - 1;
+ else
+ mem->ranges[i].start = mend + 1;
+ break;
+ }
+
+ /* If a split happened, add the split to array */
+ if (!temp_range.end)
+ return 0;
+
+ /* Split happened */
+ if (i == mem->max_nr_ranges - 1)
+ return -ENOMEM;
+
+ /* Location where new range should go */
+ j = i + 1;
+ if (j < mem->nr_ranges) {
+ /* Move over all ranges one slot towards the end */
+ for (i = mem->nr_ranges - 1; i >= j; i--)
+ mem->ranges[i + 1] = mem->ranges[i];
+ }
+
+ mem->ranges[j].start = temp_range.start;
+ mem->ranges[j].end = temp_range.end;
+ mem->nr_ranges++;
+ return 0;
+}
+
+int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
+ void **addr, unsigned long *sz)
+{
+ Elf64_Ehdr *ehdr;
+ Elf64_Phdr *phdr;
+ unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
+ unsigned char *buf;
+ unsigned int cpu, i;
+ unsigned long long notes_addr;
+ unsigned long mstart, mend;
+
+ /* extra phdr for vmcoreinfo elf note */
+ nr_phdr = nr_cpus + 1;
+ nr_phdr += mem->nr_ranges;
+
+ /*
+ * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
+ * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
+ * I think this is required by tools like gdb. So same physical
+ * memory will be mapped in two elf headers. One will contain kernel
+ * text virtual addresses and other will have __va(physical) addresses.
+ */
+
+ nr_phdr++;
+ elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
+ elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
+
+ buf = vzalloc(elf_sz);
+ if (!buf)
+ return -ENOMEM;
+
+ ehdr = (Elf64_Ehdr *)buf;
+ phdr = (Elf64_Phdr *)(ehdr + 1);
+ memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+ ehdr->e_ident[EI_CLASS] = ELFCLASS64;
+ ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
+ ehdr->e_ident[EI_VERSION] = EV_CURRENT;
+ ehdr->e_ident[EI_OSABI] = ELF_OSABI;
+ memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
+ ehdr->e_type = ET_CORE;
+ ehdr->e_machine = ELF_ARCH;
+ ehdr->e_version = EV_CURRENT;
+ ehdr->e_phoff = sizeof(Elf64_Ehdr);
+ ehdr->e_ehsize = sizeof(Elf64_Ehdr);
+ ehdr->e_phentsize = sizeof(Elf64_Phdr);
+
+ /* Prepare one phdr of type PT_NOTE for each present cpu */
+ for_each_present_cpu(cpu) {
+ phdr->p_type = PT_NOTE;
+ notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
+ phdr->p_offset = phdr->p_paddr = notes_addr;
+ phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
+ (ehdr->e_phnum)++;
+ phdr++;
+ }
+
+ /* Prepare one PT_NOTE header for vmcoreinfo */
+ phdr->p_type = PT_NOTE;
+ phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
+ phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
+ (ehdr->e_phnum)++;
+ phdr++;
+
+ /* Prepare PT_LOAD type program header for kernel text region */
+ if (kernel_map) {
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_vaddr = (Elf64_Addr)_text;
+ phdr->p_filesz = phdr->p_memsz = _end - _text;
+ phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
+ ehdr->e_phnum++;
+ phdr++;
+ }
+
+ /* Go through all the ranges in mem->ranges[] and prepare phdr */
+ for (i = 0; i < mem->nr_ranges; i++) {
+ mstart = mem->ranges[i].start;
+ mend = mem->ranges[i].end;
+
+ phdr->p_type = PT_LOAD;
+ phdr->p_flags = PF_R|PF_W|PF_X;
+ phdr->p_offset = mstart;
+
+ phdr->p_paddr = mstart;
+ phdr->p_vaddr = (unsigned long long) __va(mstart);
+ phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
+ phdr->p_align = 0;
+ ehdr->e_phnum++;
+ phdr++;
+ pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
+ phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
+ ehdr->e_phnum, phdr->p_offset);
+ }
+
+ *addr = buf;
+ *sz = elf_sz;
+ return 0;
+}
--
2.16.2
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