Only the region described by PT_LOADs of /proc/vmcore are dumpable/readble by dumping applications. Previously, on x86/x86_64 only system ram resources will be injected into PT_LOADs. So in order to make the entire pmem resource is dumpable/readable, we need to add pmem region into the PT_LOADs of /proc/vmcore.
Here we introduce a new API walk_pmem_res() to sort out the pmem region. Note that, unlike other walk_xxx_res() API in resource.c, we walk through pmem resources without IORESOUCE_BUSY flag. This is kexec_file_load() specific, for kexec_load(), kexec-tools will have a similar change. CC: Thomas Gleixner <[email protected]> CC: Ingo Molnar <[email protected]> CC: Borislav Petkov <[email protected]> CC: Dave Hansen <[email protected]> CC: "H. Peter Anvin" <[email protected]> CC: Baoquan He <[email protected]> CC: [email protected] Signed-off-by: Li Zhijian <[email protected]> --- arch/x86/kernel/crash.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index cdd92ab43cda..97763ea804c6 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -168,6 +168,17 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg) return 0; } +/* + * This function calls the @func callback against all memory ranges, which + * are ranges marked as IORESOURCE_MEM and IORES_DESC_PERSISTENT_MEMORY. + */ +static int walk_pmem_res(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + return walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY, IORESOURCE_MEM, + start, end, arg, func); +} + /* Gather all the required information to prepare elf headers for ram regions */ static struct crash_mem *fill_up_crash_elf_data(void) { @@ -178,6 +189,7 @@ static struct crash_mem *fill_up_crash_elf_data(void) if (!nr_ranges) return NULL; + walk_pmem_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); /* * Exclusion of crash region and/or crashk_low_res may cause * another range split. So add extra two slots here. @@ -243,6 +255,7 @@ static int prepare_elf_headers(struct kimage *image, void **addr, ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback); if (ret) goto out; + walk_pmem_res(0, -1, cmem, prepare_elf64_ram_headers_callback); /* Exclude unwanted mem ranges */ ret = elf_header_exclude_ranges(cmem); -- 2.29.2
