Messages in this thread Patch in this message | | | Subject | [RFC/PATCH 4/17][kexec-tools-1.101] Fill virtual addresses for linearly mapped region | From | Vivek Goyal <> | Date | Mon, 28 Mar 2005 18:56:19 +0530 |
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o For i386, Physical memory upto 896MB is linearly mapped. Hence virtual addresses for linearly mapped region are known. o This patch sets the appropriate virtual addresses in core headers for linearly mapped region. o Enables gdb to debug linearly mapped region without any special user space utility. Otherwise, capture tools first need to analyze the core image (Read page tables and/or vm areas) and determine virtual addresses for memory chunks and then regenerate the elf headers suitable for debugging with gdb. o Some cases like 4G/4G split deviate from 896MB linearly mapped region and might have different value for PAGE_OFFSET. Probably its a good idea to export the linear region from kernel and use that instead of hard coding it.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> ---
kexec-tools-1.101-root/kexec/arch/i386/crashdump-x86.c | 26 +++++++++++++++-- kexec-tools-1.101-root/kexec/arch/i386/crashdump-x86.h | 3 + 2 files changed, 27 insertions(+), 2 deletions(-)
diff -puN kexec/arch/i386/crashdump-x86.c~kexec-tools-linearly-mapped-region-x86 kexec/arch/i386/crashdump-x86.c --- kexec-tools-1.101/kexec/arch/i386/crashdump-x86.c~kexec-tools-linearly-mapped-region-x86 2005-03-21 18:55:18.000000000 +0530 +++ kexec-tools-1.101-root/kexec/arch/i386/crashdump-x86.c 2005-03-21 18:59:07.000000000 +0530 @@ -106,10 +106,22 @@ int get_crash_memory_ranges(struct memor /* First 640K already registered */ if (start >= 0x00000000 && end <= 0x0009ffff) continue; + crash_memory_range[memory_ranges].start = start; crash_memory_range[memory_ranges].end = end; crash_memory_range[memory_ranges].type = type; memory_ranges++; + + /* Segregate linearly mapped region. */ + if ((MAXMEM - 1) >= start && (MAXMEM - 1) <= end) { + crash_memory_range[memory_ranges-1].end = MAXMEM -1; + + /* Add segregated region. */ + crash_memory_range[memory_ranges].start = MAXMEM; + crash_memory_range[memory_ranges].end = end; + crash_memory_range[memory_ranges].type = type; + memory_ranges++; + } } fclose(fp); if (exclude_crash_reserve_region(&memory_ranges) < 0) @@ -521,7 +533,12 @@ int prepare_crash_memory_elf64_headers(s phdr->p_offset = info->backup_start; else phdr->p_offset = mstart; - phdr->p_vaddr = phdr->p_paddr = mstart; + /* Handle linearly mapped region.*/ + if (mend <= (MAXMEM - 1)) + phdr->p_vaddr = mstart + PAGE_OFFSET; + else + phdr->p_vaddr = -1ULL; + phdr->p_paddr = mstart; phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; /* Do we need any alignment of segments? */ phdr->p_align = 0; @@ -612,7 +629,12 @@ int prepare_crash_memory_elf32_headers(s phdr->p_offset = info->backup_start; else phdr->p_offset = mstart; - phdr->p_vaddr = phdr->p_paddr = mstart; + /* Handle linearly mapped region.*/ + if (mend <= (MAXMEM - 1)) + phdr->p_vaddr = mstart + PAGE_OFFSET; + else + phdr->p_vaddr = ULONG_MAX; + phdr->p_paddr = mstart; phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; /* Do we need any alignment of segments? */ phdr->p_align = 0; diff -puN kexec/arch/i386/crashdump-x86.h~kexec-tools-linearly-mapped-region-x86 kexec/arch/i386/crashdump-x86.h --- kexec-tools-1.101/kexec/arch/i386/crashdump-x86.h~kexec-tools-linearly-mapped-region-x86 2005-03-21 18:55:18.000000000 +0530 +++ kexec-tools-1.101-root/kexec/arch/i386/crashdump-x86.h 2005-03-21 18:55:18.000000000 +0530 @@ -18,6 +18,9 @@ extern struct memory_range crash_reserve #define PAGE_OFFSET 0xc0000000 #define __pa(x) ((unsigned long)(x)-PAGE_OFFSET) +#define __VMALLOC_RESERVE (128 << 20) +#define MAXMEM (-PAGE_OFFSET-__VMALLOC_RESERVE) + #define CRASH_MAX_MEMMAP_NR (KEXEC_MAX_SEGMENTS + 1) #define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2) _
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