[PATCH] kexec-tools/x86: get_kernel_vaddr_and_size off-by-one fix

[Dave Young]

I got below error while tesing kexec -p:
"Can't find kernel text map area from kcore"

The case is the pt_load start addr was same as stext_sym. The checking
code should really be saddr <= stext_sym so that the right pt_load area
includes stext_sym can be matched.

This was not reported by people previously because it will fail over to
use hardcode X86_64__START_KERNEL_map to match the pt_load areas again
in later code and it sometimes succeeds because of kernel address
randomization.

With this change according to my test stext_sym checking can garantee
falling into right pt_load area if we get correct stext_sym.

Signed-off-by: Dave Young <***@redhat.com>
---
kexec/arch/i386/crashdump-x86.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- kexec-tools.orig/kexec/arch/i386/crashdump-x86.c
+++ kexec-tools/kexec/arch/i386/crashdump-x86.c
@@ -205,7 +205,7 @@ static int get_kernel_vaddr_and_size(str
unsigned long long size;

/* Look for kernel text mapping header. */
- if (saddr < stext_sym && eaddr > stext_sym) {
+ if (saddr <= stext_sym && eaddr > stext_sym) {
saddr = _ALIGN_DOWN(saddr, X86_64_KERN_VADDR_ALIGN);
elf_info->kern_vaddr_start = saddr;
size = eaddr - saddr;

[Simon Horman]

Post by Dave Young
"Can't find kernel text map area from kcore"
The case is the pt_load start addr was same as stext_sym. The checking
code should really be saddr <= stext_sym so that the right pt_load area
includes stext_sym can be matched.
This was not reported by people previously because it will fail over to
use hardcode X86_64__START_KERNEL_map to match the pt_load areas again
in later code and it sometimes succeeds because of kernel address
randomization.
With this change according to my test stext_sym checking can garantee
falling into right pt_load area if we get correct stext_sym.

Thanks, applied.