diff options
Diffstat (limited to 'kernel/crash_core.c')
| -rw-r--r-- | kernel/crash_core.c | 70 |
1 files changed, 49 insertions, 21 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 078fe5bc5a74..4f21fc3b108b 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -21,25 +21,36 @@ #include <linux/reboot.h> #include <linux/btf.h> #include <linux/objtool.h> +#include <linux/delay.h> +#include <linux/panic.h> #include <asm/page.h> #include <asm/sections.h> -#include <crypto/sha1.h> - #include "kallsyms_internal.h" #include "kexec_internal.h" /* Per cpu memory for storing cpu states in case of system crash. */ note_buf_t __percpu *crash_notes; +/* time to wait for possible DMA to finish before starting the kdump kernel + * when a CMA reservation is used + */ +#define CMA_DMA_TIMEOUT_SEC 10 + #ifdef CONFIG_CRASH_DUMP int kimage_crash_copy_vmcoreinfo(struct kimage *image) { - struct page *vmcoreinfo_page; + struct page *vmcoreinfo_base; + struct page *vmcoreinfo_pages[DIV_ROUND_UP(VMCOREINFO_BYTES, PAGE_SIZE)]; + unsigned int order, nr_pages; + int i; void *safecopy; + nr_pages = DIV_ROUND_UP(VMCOREINFO_BYTES, PAGE_SIZE); + order = get_order(VMCOREINFO_BYTES); + if (!IS_ENABLED(CONFIG_CRASH_DUMP)) return 0; if (image->type != KEXEC_TYPE_CRASH) @@ -54,12 +65,15 @@ int kimage_crash_copy_vmcoreinfo(struct kimage *image) * happens to generate vmcoreinfo note, hereby we rely on * vmap for this purpose. */ - vmcoreinfo_page = kimage_alloc_control_pages(image, 0); - if (!vmcoreinfo_page) { + vmcoreinfo_base = kimage_alloc_control_pages(image, order); + if (!vmcoreinfo_base) { pr_warn("Could not allocate vmcoreinfo buffer\n"); return -ENOMEM; } - safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL); + for (i = 0; i < nr_pages; i++) + vmcoreinfo_pages[i] = vmcoreinfo_base + i; + + safecopy = vmap(vmcoreinfo_pages, nr_pages, VM_MAP, PAGE_KERNEL); if (!safecopy) { pr_warn("Could not vmap vmcoreinfo buffer\n"); return -ENOMEM; @@ -97,6 +111,14 @@ int kexec_crash_loaded(void) } EXPORT_SYMBOL_GPL(kexec_crash_loaded); +static void crash_cma_clear_pending_dma(void) +{ + if (!crashk_cma_cnt) + return; + + mdelay(CMA_DMA_TIMEOUT_SEC * 1000); +} + /* * No panic_cpu check version of crash_kexec(). This function is called * only when panic_cpu holds the current CPU number; this is the only CPU @@ -119,6 +141,7 @@ void __noclone __crash_kexec(struct pt_regs *regs) crash_setup_regs(&fixed_regs, regs); crash_save_vmcoreinfo(); machine_crash_shutdown(&fixed_regs); + crash_cma_clear_pending_dma(); machine_kexec(kexec_crash_image); } kexec_unlock(); @@ -128,17 +151,7 @@ STACK_FRAME_NON_STANDARD(__crash_kexec); __bpf_kfunc void crash_kexec(struct pt_regs *regs) { - int old_cpu, this_cpu; - - /* - * Only one CPU is allowed to execute the crash_kexec() code as with - * panic(). Otherwise parallel calls of panic() and crash_kexec() - * may stop each other. To exclude them, we use panic_cpu here too. - */ - old_cpu = PANIC_CPU_INVALID; - this_cpu = raw_smp_processor_id(); - - if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) { + if (panic_try_start()) { /* This is the 1st CPU which comes here, so go ahead. */ __crash_kexec(regs); @@ -146,7 +159,7 @@ __bpf_kfunc void crash_kexec(struct pt_regs *regs) * Reset panic_cpu to allow another panic()/crash_kexec() * call. */ - atomic_set(&panic_cpu, PANIC_CPU_INVALID); + panic_reset(); } } @@ -259,6 +272,20 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, return 0; } +/** + * crash_exclude_mem_range - exclude a mem range for existing ranges + * @mem: mem->range contains an array of ranges sorted in ascending order + * @mstart: the start of to-be-excluded range + * @mend: the start of to-be-excluded range + * + * If you are unsure if a range split will happen, to avoid function call + * failure because of -ENOMEM, always make sure + * mem->max_nr_ranges == mem->nr_ranges + 1 + * before calling the function each time. + * + * returns 0 if a memory range is excluded successfully + * return -ENOMEM if mem->ranges doesn't have space to hold split ranges + */ int crash_exclude_mem_range(struct crash_mem *mem, unsigned long long mstart, unsigned long long mend) { @@ -318,6 +345,7 @@ int crash_exclude_mem_range(struct crash_mem *mem, return 0; } +EXPORT_SYMBOL_GPL(crash_exclude_mem_range); ssize_t crash_get_memory_size(void) { @@ -338,7 +366,7 @@ static int __crash_shrink_memory(struct resource *old_res, { struct resource *ram_res; - ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); + ram_res = kzalloc_obj(*ram_res); if (!ram_res) return -ENOMEM; @@ -352,7 +380,7 @@ static int __crash_shrink_memory(struct resource *old_res, old_res->start = 0; old_res->end = 0; } else { - crashk_res.end = ram_res->start - 1; + old_res->end = ram_res->start - 1; } crash_free_reserved_phys_range(ram_res->start, ram_res->end); @@ -436,7 +464,7 @@ void crash_save_cpu(struct pt_regs *regs, int cpu) memset(&prstatus, 0, sizeof(prstatus)); prstatus.common.pr_pid = current->pid; elf_core_copy_regs(&prstatus.pr_reg, regs); - buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, + buf = append_elf_note(buf, NN_PRSTATUS, NT_PRSTATUS, &prstatus, sizeof(prstatus)); final_note(buf); } |