Hi Laura,
On 29/11/16 18:55, Laura Abbott wrote:
> __pa_symbol is technically the marco that should be used for kernel
macro
> symbols. Switch to this as a pre-requisite for DEBUG_VIRTUAL which
> will do bounds checking. As part of this, introduce lm_alias, a
> macro which wraps the __va(__pa(...)) idiom used a few places to
> get the alias.
> diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
> index d55a7b0..4f0c77d 100644
> --- a/arch/arm64/kernel/hibernate.c
> +++ b/arch/arm64/kernel/hibernate.c
> @@ -484,7 +481,7 @@ int swsusp_arch_resume(void)
> * Since we only copied the linear map, we need to find restore_pblist's
> * linear map address.
> */
> - lm_restore_pblist = LMADDR(restore_pblist);
> + lm_restore_pblist = lm_alias(restore_pblist);
>
> /*
> * We need a zero page that is zero before & after resume in order to
This change causes resume from hibernate to panic in:
> VIRTUAL_BUG_ON(x < (unsigned long) KERNEL_START ||
> x > (unsigned long) KERNEL_END);
It looks like kaslr's relocation code has already fixed restore_pblist, so your
debug virtual check catches this doing the wrong thing. My bug.
readelf -s vmlinux | grep ...
> 103495: ffff000008080000 0 NOTYPE GLOBAL DEFAULT 1 _text
> 92104: ffff000008e43860 8 OBJECT GLOBAL DEFAULT 24 restore_pblist
> 105442: ffff000008e85000 0 NOTYPE GLOBAL DEFAULT 24 _end
But restore_pblist == 0xffff800971b7f998 when passed to __phys_addr_symbol().
This fixes the problem:
----------------%<----------------
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 4f0c77d2ff7a..8bed26a2d558 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -457,7 +457,6 @@ int swsusp_arch_resume(void)
void *zero_page;
size_t exit_size;
pgd_t *tmp_pg_dir;
- void *lm_restore_pblist;
phys_addr_t phys_hibernate_exit;
void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
void *, phys_addr_t, phys_addr_t);
@@ -478,12 +477,6 @@ int swsusp_arch_resume(void)
goto out;
/*
- * Since we only copied the linear map, we need to find restore_pblist's
- * linear map address.
- */
- lm_restore_pblist = lm_alias(restore_pblist);
-
- /*
* We need a zero page that is zero before & after resume in order to
* to break before make on the ttbr1 page tables.
*/
@@ -534,7 +527,7 @@ int swsusp_arch_resume(void)
}
hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
- resume_hdr.reenter_kernel, lm_restore_pblist,
+ resume_hdr.reenter_kernel, restore_pblist,
resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));
out:
----------------%<----------------
I can post it as a separate fixes patch if you prefer.
I also tested kexec. FWIW:
Tested-by: James Morse <james.morse@xxxxxxx>
Thanks,
James
[0] Trace
[ 4.191607] Freezing user space processes ... (elapsed 0.000 seconds) done.
[ 4.224251] random: fast init done
[ 4.243825] PM: Using 3 thread(s) for decompression.
[ 4.243825] PM: Loading and decompressing image data (90831 pages)...
[ 4.255257] hibernate: Hibernated on CPU 0 [mpidr:0x100]
[ 5.213469] PM: Image loading progress: 0%
[ 5.579886] PM: Image loading progress: 10%
[ 5.740234] ata2: SATA link down (SStatus 0 SControl 0)
[ 5.760435] PM: Image loading progress: 20%
[ 5.970647] PM: Image loading progress: 30%
[ 6.563108] PM: Image loading progress: 40%
[ 6.848389] PM: Image loading progress: 50%
[ 7.526272] PM: Image loading progress: 60%
[ 7.702727] PM: Image loading progress: 70%
[ 7.899754] PM: Image loading progress: 80%
[ 8.100703] PM: Image loading progress: 90%
[ 8.300978] PM: Image loading progress: 100%
[ 8.305441] PM: Image loading done.
[ 8.308975] PM: Read 363324 kbytes in 4.05 seconds (89.70 MB/s)
[ 8.344299] PM: quiesce of devices complete after 22.706 msecs
[ 8.350762] PM: late quiesce of devices complete after 0.596 msecs
[ 8.381334] PM: noirq quiesce of devices complete after 24.365 msecs
[ 8.387729] Disabling non-boot CPUs ...
[ 8.412500] CPU1: shutdown
[ 8.415211] psci: CPU1 killed.
[ 8.460465] CPU2: shutdown
[ 8.463175] psci: CPU2 killed.
[ 8.504447] CPU3: shutdown
[ 8.507156] psci: CPU3 killed.
[ 8.540375] CPU4: shutdown
[ 8.543084] psci: CPU4 killed.
[ 8.580333] CPU5: shutdown
[ 8.583043] psci: CPU5 killed.
[ 8.601206] ------------[ cut here ]------------
[ 8.601206] kernel BUG at ../arch/arm64/mm/physaddr.c:25!
[ 8.601206] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[ 8.601206] Modules linked in:
[ 8.601206] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc7-00010-g27c672
[ 8.601206] Hardware name: ARM Juno development board (r1) (DT)
[ 8.601206] task: ffff800976ca8000 task.stack: ffff800976c3c000
[ 8.601206] PC is at __phys_addr_symbol+0x30/0x34
[ 8.601206] LR is at swsusp_arch_resume+0x304/0x588
[ 8.601206] pc : [<ffff0000080992d8>] lr : [<ffff0000080938b4>] pstate: 20005
[ 8.601206] sp : ffff800976c3fca0
[ 8.601206] x29: ffff800976c3fca0 x28: ffff000008bee000
[ 8.601206] x27: 000000000e5ea000 x26: ffff000008e83000
[ 8.601206] x25: 0000000000000801 x24: 0000000040000000
[ 8.601206] x23: 0000000000000000 x22: 000000000e00d000
[ 8.601206] x21: ffff808000000000 x20: ffff800080000000
[ 8.601206] x19: 0000000000000000 x18: 4000000000000000
[ 8.601206] x17: 0000000000000000 x16: 0000000000000694
[ 8.601206] x15: ffff000008bee000 x14: 0000000000000008
[ 8.601206] x13: 0000000000000000 x12: 003d090000000000
[ 8.601206] x11: 0000000000000001 x10: fffffffff1a0f000
[ 8.601206] x9 : 0000000000000001 x8 : ffff800971a0aff8
[ 8.601206] x7 : 0000000000000001 x6 : 000000000000003f
[ 8.601206] x5 : 0000000000000040 x4 : 0000000000000000
[ 8.601206] x3 : ffff807fffffffff x2 : 0000000000000000
[ 8.601206] x1 : ffff000008e85000 x0 : ffff80097152b578
[ 8.601206]
[ 8.601206] Process swapper/0 (pid: 1, stack limit = 0xffff800976c3c020)
[ 8.601206] Stack: (0xffff800976c3fca0 to 0xffff800976c40000)
[ 8.601206] Call trace:
[ 8.601206] Exception stack(0xffff800976c3fad0 to 0xffff800976c3fc00)
[ 8.601206] [<ffff0000080992d8>] __phys_addr_symbol+0x30/0x34
[ 8.601206] [<ffff0000080fe340>] hibernation_restore+0xf8/0x130
[ 8.601206] [<ffff0000080fe3e4>] load_image_and_restore+0x6c/0x70
[ 8.601206] [<ffff0000080fe640>] software_resume+0x258/0x288
[ 8.601206] [<ffff0000080830b8>] do_one_initcall+0x38/0x128
[ 8.601206] [<ffff000008c60cf4>] kernel_init_freeable+0x1ac/0x250
[ 8.601206] [<ffff0000088acd10>] kernel_init+0x10/0x100
[ 8.601206] [<ffff000008082e80>] ret_from_fork+0x10/0x50
[ 8.601206] Code: b0005aa1 f9475c21 cb010000 d65f03c0 (d4210000)
[ 8.601206] ---[ end trace e15be9f4f989f0b5 ]---
[ 8.601206] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0b
[ 8.601206]
[ 8.601206] Kernel Offset: disabled
[ 8.601206] Memory Limit: none
[ 8.601206] ---[ end Kernel panic - not syncing: Attempted to kill init! exib
[ 8.601206]
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