Re: [x86/KASLR] ed9f007ee6: -- System halted

[Baoquan He]

On 07/01/16 at 08:16pm, Ye Xiaolong wrote:
> On Fri, Jul 01, 2016 at 03:50:32PM +0800, Baoquan He wrote:
> >Hi Xiaolong,
> >
> >Could you please apply below patch and see if it works for you?
> 
> Hi, Baoquan,
> 
> Please check enclosed dmesg after apply your fix patch, does it meet
> your expectation?

It works, but didn't get a random phy addr. I am a little worried. I
guess your system has a very small physical memory space. Could you
apply attached patch on top of fix patch and Yinghai's debug patch and
paste the result? I want to check the physical memory and mem_avoid
region to make sure it.

Or if you can paste /proc/iomem I can have a quick check, then you don't
need to run the patch.

> 
> Thanks,
> Xiaolong
> 
> >
> >From 46c2a9ecd11f61d952253e005bbd7dcbffa652fb Mon Sep 17 00:00:00 2001
> >From: Baoquan He <b...@redhat.com>
> >Date: Fri, 1 Jul 2016 15:34:40 +0800
> >Subject: [PATCH] x86/KASLR: Fix code bug of finding earliest overlap
> >
> >Signed-off-by: Baoquan He <b...@redhat.com>
> >---
> > arch/x86/boot/compressed/kaslr.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> >diff --git a/arch/x86/boot/compressed/kaslr.c 
> >b/arch/x86/boot/compressed/kaslr.c
> >index 304c5c3..8e1fdf7 100644
> >--- a/arch/x86/boot/compressed/kaslr.c
> >+++ b/arch/x86/boot/compressed/kaslr.c
> >@@ -285,6 +285,7 @@ static bool mem_avoid_overlap(struct mem_vector *img,
> >             if (mem_overlaps(img, &mem_avoid[i]) &&
> >                 mem_avoid[i].start < earliest) {
> >                     *overlap = mem_avoid[i];
> >+                    earliest = overlap->start;
> >                     is_overlapping = true;
> >             }
> >     }
> >@@ -299,6 +300,7 @@ static bool mem_avoid_overlap(struct mem_vector *img,
> > 
> >             if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) {
> >                     *overlap = avoid;
> >+                    earliest = overlap->start;
> >                     is_overlapping = true;
> >             }
> > 
> >-- 
> >2.5.5
> >



diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 8e1fdf7..f2bd558 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -260,6 +260,12 @@ static void mem_avoid_init(unsigned long input, unsigned 
long input_size,
        mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params);
        add_identity_map(mem_avoid[MEM_AVOID_BOOTPARAMS].start,
                         mem_avoid[MEM_AVOID_BOOTPARAMS].size);
+       for(int i=0; i<MEM_AVOID_MAX; i++)
+       debug_printf("      mem_avoid[%d]: [0x%010lx-0x%010lx] 0x%08lx: size\n",
+                i,
+                 (unsigned long)mem_avoid[i].start,
+                 (unsigned long) mem_avoid[i].start + mem_avoid[i].size - 1,
+                 (unsigned long)mem_avoid[i].size);
 
        /* We don't need to set a mapping for setup_data. */
 
@@ -376,6 +382,11 @@ static void process_e820_entry(struct e820entry *entry,
        if (entry->type != E820_RAM)
                return;
 
+       debug_printf("      e820 entry: [0x%010lx-0x%010lx] 0x%08lx: size\n",
+                 (unsigned long)entry->addr,
+                 (unsigned long)entry->addr + entry->size - 1,
+                 (unsigned long)entry->size);
+
        /* On 32-bit, ignore entries entirely above our maximum. */
        if (IS_ENABLED(CONFIG_X86_32) && entry->addr >= KERNEL_IMAGE_SIZE)
                return;