This patch implements showing kexec memory area via /proc/iomem. For example, with this patch we can see: # cat /proc/iomem ... 00100000-7ffeffff : System RAM 01000000-012e1424 : Kernel code 012e1425-015f1aff : Kernel data 0166b000-01b4b88f : Kernel bss 02000000-083fffff : Crash kernel 02000000-028fffff : Used 02900000-083fffff : Unused ... So that user can know how much memory the kernel uses for crash kernel. Signed-off-by: WANG Cong <amwang@xxxxxxxxxx> Cc: Neil Horman <nhorman@xxxxxxxxxx> Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> --- diff --git a/kernel/kexec.c b/kernel/kexec.c index f336e21..01673ad 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -931,6 +931,8 @@ static int kimage_load_segment(struct kimage *image, */ struct kimage *kexec_image; struct kimage *kexec_crash_image; +struct resource *kexec_res = NULL; +struct resource *kexec_free_res = NULL; static DEFINE_MUTEX(kexec_mutex); @@ -939,6 +941,8 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, { struct kimage **dest_image, *image; int result; + unsigned long kexec_start = crashk_res.start; + unsigned long kexec_end = kexec_start; /* We only trust the superuser with rebooting the system. */ if (!capable(CAP_SYS_BOOT)) @@ -994,6 +998,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, kimage_free(xchg(&kexec_crash_image, NULL)); result = kimage_crash_alloc(&image, entry, nr_segments, segments); + kexec_end += KEXEC_CONTROL_PAGE_SIZE; } if (result) goto out; @@ -1008,6 +1013,42 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, result = kimage_load_segment(image, &image->segment[i]); if (result) goto out; + if (flags & KEXEC_ON_CRASH) + kexec_end += image->segment[i].memsz; + } + if (flags & KEXEC_ON_CRASH) { + if (kexec_res) { + release_resource(kexec_res); + release_resource(kexec_free_res); + kfree(kexec_res); + kfree(kexec_free_res); + } + kexec_res = kzalloc(sizeof(*kexec_res), GFP_KERNEL); + if (!kexec_res) { + result = -ENOMEM; + goto out; + } + kexec_free_res = kzalloc(sizeof(*kexec_free_res), GFP_KERNEL); + if (!kexec_free_res) { + result = -ENOMEM; + goto out_free; + } + kexec_res->name = "Used"; + kexec_res->start = kexec_start; + kexec_res->end = roundup(kexec_end, 1<<20) - 1; + kexec_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; + if (insert_resource(&crashk_res, kexec_res)) { + result = -EBUSY; + goto out_free; + } + kexec_free_res->name = "Unused"; + kexec_free_res->start = kexec_res->end + 1; + kexec_free_res->end = crashk_res.end; + kexec_free_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; + if (insert_resource(&crashk_res, kexec_free_res)) { + result = -EBUSY; + goto out_release; + } } kimage_terminate(image); } @@ -1019,6 +1060,13 @@ out: kimage_free(image); return result; + +out_free: + kfree(kexec_free_res); + kfree(kexec_res); +out_release: + release_resource(kexec_res); + goto out; } #ifdef CONFIG_COMPAT -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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