Pass vmcoreinfo's address and size #2
Subsystems (2)
PATCH 2/2 Pass vmcoreinfo's address and size #2
[2/2] [kexec-tools] Pass vmcoreinfo's address and size
The patch is for kexec-tools-testing-20070330.
(http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/)
kexec command gets the address and size of the vmcoreinfo data from /sys/kernel/vmcoreinfo, and passes them to the second kernel through ELF header of /proc/vmcore. When the second kernel is booting, the kernel gets them from the ELF header and creates vmcoreinfo's PT_NOTE segment into /proc/vmcore.
Changelog:
- Fix the problem that the kexec command cannnot be executed on kernels without vmcoreinfo.
Thanks
Ken'ichi Ohmichi
---
---
kexec/crashdump-elf.c +22 -1
@@ -36,6 +36,8 @@ int FUNC(struct kexec_info *info,char *bufp;long int nr_cpus =0 ;uint64_t notes_addr, notes_len; +uint64_t vmcoreinfo_addr, vmcoreinfo_len; +int has_vmcoreinfo =0 ;int (*get_note_info)(int cpu,uint64_t *addr,uint64_t *len);if (xen_present ())
@@ -47,7 +49,11 @@ int FUNC(struct kexec_info *info,return -1 ; } - sz =sizeof (EHDR ) + nr_cpus *sizeof (PHDR ) + ranges *sizeof (PHDR ); +if (get_kernel_vmcoreinfo (&vmcoreinfo_addr, &vmcoreinfo_len) ==0 ) { + has_vmcoreinfo =1 ; + } + + sz =sizeof (EHDR ) + (nr_cpus + has_vmcoreinfo) *sizeof (PHDR ) + ranges *sizeof (PHDR );/* * Certain architectures such as x86_64 and ia64 require a separate
@@ -148,6 +154,21 @@ int FUNC(struct kexec_info *info,dfprintf_phdr (stdout,"Elf header" , phdr); } +if (has_vmcoreinfo) { + phdr = (PHDR *) bufp; + bufp +=sizeof (PHDR ); + phdr->p_type =PT_NOTE ; + phdr->p_flags =0 ; + phdr->p_offset = phdr->p_paddr = vmcoreinfo_addr; + phdr->p_vaddr =0 ; + phdr->p_filesz = phdr->p_memsz = vmcoreinfo_len; +/* Do we need any alignment of segments? */ + phdr->p_align =0 ; + + (elf->e_phnum)++; +dfprintf_phdr (stdout,"vmcoreinfo header" , phdr); + } +/* Setup an PT_LOAD type program header for the region where * Kernel is mapped if info->kern_size is non-zero. */
kexec/crashdump.c +29 -0
@@ -108,3 +108,32 @@ int get_crash_notes_per_cpu(int cpu, uinreturn 0 ; } + +/* Returns the physical address of start of crash notes buffer for a kernel. */ +int get_kernel_vmcoreinfo (uint64_t *addr,uint64_t *len) +{ +char kdump_info[PATH_MAX ]; +char line[MAX_LINE ]; +int count; +FILE *fp; +unsigned long long temp, temp2; + + *addr =0 ; + *len =0 ; + +sprintf (kdump_info,"/sys/kernel/vmcoreinfo" ); + fp =fopen (kdump_info,"r" ); +if (!fp) +return 0 ; + +if (!fgets (line,sizeof (line), fp)) +die ("Cannot parse %s: %s\n" , kdump_info,strerror (errno)); + count =sscanf (line,"%Lx %Lx" , &temp, &temp2); +if (count !=2 ) +die ("Cannot parse %s: %s\n" , kdump_info,strerror (errno)); + + *addr = (uint64_t ) temp; + *len = (uint64_t ) temp2; + +return 0 ; +}
kexec/crashdump.h +1 -0
@@ -2,6 +2,7 @@#define CRASHDUMP_H extern int get_crash_notes_per_cpu (int cpu,uint64_t *addr,uint64_t *len); +extern int get_kernel_vmcoreinfo (uint64_t *addr,uint64_t *len);/* Need to find a better way to determine per cpu notes section size. */ #define MAX_NOTE_BYTES 1024
_
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