[PATCH 2/3 v2] x86/kexec_file: add e820 entry in case e820 type string matches to io resource name

From: Lianbo Jiang
Date: Wed Sep 19 2018 - 08:53:35 EST


kdump use walk_iomem_res_desc to iterate io resources then add matched
desc to e820 table for kdump kernel.

But IORES_DESC_NONE resource type includes several different e820 types,
we need add exact e820 type to kdump kernel e820 table thus need an extra
checking in memmap_entry_callback() to match the e820 type and resource
name.

Signed-off-by: Dave Young <dyoung@xxxxxxxxxx>
Signed-off-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
---
arch/x86/include/asm/e820/api.h | 2 ++
arch/x86/kernel/crash.c | 6 +++++-
arch/x86/kernel/e820.c | 2 +-
kernel/resource.c | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h
index 62be73b23d5c..6d5451b36e80 100644
--- a/arch/x86/include/asm/e820/api.h
+++ b/arch/x86/include/asm/e820/api.h
@@ -42,6 +42,8 @@ extern void e820__register_nosave_regions(unsigned long limit_pfn);

extern int e820__get_entry_type(u64 start, u64 end);

+extern const char *e820_type_to_string(struct e820_entry *entry);
+
/*
* Returns true iff the specified range [start,end) is completely contained inside
* the ISA region.
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index f631a3f15587..ae724a6e0a5f 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -37,6 +37,7 @@
#include <asm/reboot.h>
#include <asm/virtext.h>
#include <asm/intel_pt.h>
+#include <asm/e820/api.h>

/* Used while preparing memory map entries for second kernel */
struct crash_memmap_data {
@@ -314,11 +315,14 @@ static int memmap_entry_callback(struct resource *res, void *arg)
struct crash_memmap_data *cmd = arg;
struct boot_params *params = cmd->params;
struct e820_entry ei;
+ const char *name;

ei.addr = res->start;
ei.size = resource_size(res);
ei.type = cmd->type;
- add_e820_entry(params, &ei);
+ name = e820_type_to_string(&ei);
+ if (res->name && !strcmp(name, res->name))
+ add_e820_entry(params, &ei);

return 0;
}
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index c88c23c658c1..f9761b2f7abb 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1012,7 +1012,7 @@ void __init e820__finish_early_params(void)
}
}

-static const char *__init e820_type_to_string(struct e820_entry *entry)
+const char *e820_type_to_string(struct e820_entry *entry)
{
switch (entry->type) {
case E820_TYPE_RESERVED_KERN: /* Fall-through: */
diff --git a/kernel/resource.c b/kernel/resource.c
index f5d9fc70a04c..cc90633f35f9 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -366,6 +366,7 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,
res->end = p->end;
res->flags = p->flags;
res->desc = p->desc;
+ res->name = p->name;
return 0;
}

--
2.17.1