Enabled kexec to use the per allocated memory hole for kexec crash FDT
which is exported via /sys/kernel/kexec_crash_fdt and
/sys/kernel/kexec_crash_fdt_size sysfs files. Using this pre-allocated
memory hole for kdump fdt will allow the kernel to keep the kdump fdt
up-to-date with the latest CPU information.
In case a pre-allocated memory hole is used for kdump fdt, the kdump fdt
the segment is not included in SHA calculation because kdump fdt will be
modified by the kernel.
To maintain the backward compatibility, we fall back to the old option of
finding hole for kdump fdt segment if the pre-allocated buffer is not provided
by the kernel.
Signed-off-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
---
kexec/arch/ppc64/kexec-elf-ppc64.c | 11 +++++--
kexec/arch/ppc64/kexec-ppc64.c | 49 ++++++++++++++++++++++++++++++
kexec/kexec.c | 9 ++++++
kexec/kexec.h | 4 +++
4 files changed, 71 insertions(+), 2 deletions(-)
diff --git a/kexec/arch/ppc64/kexec-elf-ppc64.c b/kexec/arch/ppc64/kexec-elf-ppc64.c
index 695b8b0..8e66ef0 100644
--- a/kexec/arch/ppc64/kexec-elf-ppc64.c
+++ b/kexec/arch/ppc64/kexec-elf-ppc64.c
@@ -329,8 +329,15 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,
if (result < 0)
return result;
- my_dt_offset = add_buffer(info, seg_buf, seg_size, seg_size,
- 0, 0, max_addr, -1);
+ if (kexec_crash_fdt) {
+ my_dt_offset = kexec_crash_fdt;
+ add_segment_phys_virt(info, seg_buf, seg_size,
+ my_dt_offset, kexec_crash_fdt_size, 0);
+ }
+ else {
+ my_dt_offset = add_buffer(info, seg_buf, seg_size, seg_size,
+ 0, 0, max_addr, -1);
+ }
#ifdef NEED_RESERVE_DTB
/* patch reserve map address for flattened device-tree
diff --git a/kexec/arch/ppc64/kexec-ppc64.c b/kexec/arch/ppc64/kexec-ppc64.c
index 5b17740..d4385bd 100644
--- a/kexec/arch/ppc64/kexec-ppc64.c
+++ b/kexec/arch/ppc64/kexec-ppc64.c
@@ -24,6 +24,7 @@
#include <errno.h>
#include <stdint.h>
#include <string.h>
+#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
@@ -373,6 +374,52 @@ void scan_reserved_ranges(unsigned long kexec_flags, int *range_index)
*range_index = i;
}
+void get_kexec_crash_fdt_details(unsigned long kexec_flags)
+{
+ int fd, len;
+ char buf[MAXBYTES] = { 0 };
+
+ const char * const kexec_fdt_sysfs = "/sys/kernel/kexec_crash_fdt";
+ const char * const kexec_fdt_size_sysfs = "/sys/kernel/kexec_crash_fdt_size";
+
+ fd = open(kexec_fdt_sysfs, O_RDONLY);
+ if (fd < 0)
+ return;
+
+ len = read(fd, buf, MAXBYTES);
+ if (len < 0)
+ goto err_out;
+
+ kexec_crash_fdt = strtoul(buf, NULL, 16);
+
+ fd = open(kexec_fdt_size_sysfs, O_RDONLY);
+ if (fd < 0)
+ goto err_out;
+
+ len = read(fd, buf, MAXBYTES);
+ if (len < 0)
+ goto err_out;
+
+ kexec_crash_fdt_size = strtoul(buf, NULL, 10);
+
+ exclude_range[nr_exclude_ranges].start = kexec_crash_fdt;
+ exclude_range[nr_exclude_ranges].end = kexec_crash_fdt + \
+ kexec_crash_fdt_size;
+ nr_exclude_ranges++;
+
+ if (nr_exclude_ranges >= max_memory_ranges)
+ realloc_memory_ranges();
+
+ goto out;
+
+err_out:
+ kexec_crash_fdt = kexec_fdt_size = 0;
+
+out:
+ close (fd);
+ return;
+}
+
/* Return 0 if fname/value valid, -1 otherwise */
int get_devtree_value(const char *fname, unsigned long long *value)
{
@@ -804,6 +851,8 @@ int setup_memory_ranges(unsigned long kexec_flags)
goto out;
if (get_devtree_details(kexec_flags))
goto out;
+ if (kexec_flags & KEXEC_ON_CRASH)
+ get_kexec_crash_fdt_details(kexec_flags);
for (i = 0; i < nr_exclude_ranges; i++) {
/* If first exclude range does not start with 0, include the
diff --git a/kexec/kexec.c b/kexec/kexec.c
index f63b36b..89283f7 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -62,6 +62,10 @@ static unsigned long kexec_flags = 0;
/* Flags for kexec file (fd) based syscall */
static unsigned long kexec_file_flags = 0;
int kexec_debug = 0;
+#if defined(__powerpc__) || defined(__powerpc64__)
+uint64_t kexec_crash_fdt;
+uint32_t kexec_cras_fdt_size;
+#endif
void dbgprint_mem_range(const char *prefix, struct memory_range *mr, int nr_mr)
{
@@ -672,6 +676,11 @@ static void update_purgatory(struct kexec_info *info)
if (info->segment[i].mem == (void *)info->rhdr.rel_addr) {
continue;
}
+
+#if defined(__powerpc__) || defined(__powerpc64__)
+ if (kexec_crash_fdt && (unsigned long)info->segment[i].mem == kexec_crash_fdt)
+ continue;
+#endif
sha256_update(&ctx, info->segment[i].buf,
info->segment[i].bufsz);
nullsz = info->segment[i].memsz - info->segment[i].bufsz;
diff --git a/kexec/kexec.h b/kexec/kexec.h
index 595dd68..48e8b9f 100644
--- a/kexec/kexec.h
+++ b/kexec/kexec.h
@@ -205,6 +205,10 @@ struct file_type {
extern struct file_type file_type[];
extern int file_types;
+#if defined(__powerpc__) || defined(__powerpc64__)
+extern uint64_t fdt;
+extern uint32_t fdt_size;
+#endif
#define OPT_HELP 'h'
#define OPT_VERSION 'v'
--
2.34.1
---
Sourabh Jain (5):
powerpc/kdump: export functions from file_load_64.c
powerpc/kdump: setup kexec crash FDT
powerpc/kdump: update kexec crash FDT on CPU hot add event
powerpc/kdump: enable kexec_file_load system call to use kexec crash
FDT
powerpc/kdump: export kexec crash FDT details via sysfs
arch/powerpc/Kconfig | 11 +
arch/powerpc/include/asm/kexec.h | 10 +
arch/powerpc/kexec/core_64.c | 318 +++++++++++++++++++
arch/powerpc/kexec/elf_64.c | 22 +-
arch/powerpc/kexec/file_load_64.c | 239 +-------------
arch/powerpc/platforms/pseries/hotplug-cpu.c | 7 +
6 files changed, 369 insertions(+), 238 deletions(-)
--
2.34.1
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