diff options
| author | Russell King <rmk+kernel@armlinux.org.uk> | 2021-02-01 19:40:01 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2021-02-05 10:23:29 +0000 |
| commit | 4d62e81b60d4025e2dfcd5ea531cc1394ce9226f (patch) | |
| tree | 2254e87cef4bea58743d06f4a835384e1faf42d2 /arch/arm/kernel/relocate_kernel.S | |
| parent | 9c698bff66ab4914bb3d71da7dc6112519bde23e (diff) | |
ARM: kexec: fix oops after TLB are invalidated
Giancarlo Ferrari reports the following oops while trying to use kexec:
Unable to handle kernel paging request at virtual address 80112f38
pgd = fd7ef03e
[80112f38] *pgd=0001141e(bad)
Internal error: Oops: 80d [#1] PREEMPT SMP ARM
...
This is caused by machine_kexec() trying to set the kernel text to be
read/write, so it can poke values into the relocation code before
copying it - and an interrupt occuring which changes the page tables.
The subsequent writes then hit read-only sections that trigger a
data abort resulting in the above oops.
Fix this by copying the relocation code, and then writing the variables
into the destination, thereby avoiding the need to make the kernel text
read/write.
Reported-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>
Tested-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/kernel/relocate_kernel.S')
| -rw-r--r-- | arch/arm/kernel/relocate_kernel.S | 38 |
1 files changed, 11 insertions, 27 deletions
diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S index 72a08786e16e..218d524360fc 100644 --- a/arch/arm/kernel/relocate_kernel.S +++ b/arch/arm/kernel/relocate_kernel.S @@ -5,14 +5,16 @@ #include <linux/linkage.h> #include <asm/assembler.h> +#include <asm/asm-offsets.h> #include <asm/kexec.h> .align 3 /* not needed for this code, but keeps fncpy() happy */ ENTRY(relocate_new_kernel) - ldr r0,kexec_indirection_page - ldr r1,kexec_start_address + adr r7, relocate_new_kernel_end + ldr r0, [r7, #KEXEC_INDIR_PAGE] + ldr r1, [r7, #KEXEC_START_ADDR] /* * If there is no indirection page (we are doing crashdumps) @@ -57,34 +59,16 @@ ENTRY(relocate_new_kernel) 2: /* Jump to relocated kernel */ - mov lr,r1 - mov r0,#0 - ldr r1,kexec_mach_type - ldr r2,kexec_boot_atags - ARM( ret lr ) - THUMB( bx lr ) - - .align - - .globl kexec_start_address -kexec_start_address: - .long 0x0 - - .globl kexec_indirection_page -kexec_indirection_page: - .long 0x0 - - .globl kexec_mach_type -kexec_mach_type: - .long 0x0 - - /* phy addr of the atags for the new kernel */ - .globl kexec_boot_atags -kexec_boot_atags: - .long 0x0 + mov lr, r1 + mov r0, #0 + ldr r1, [r7, #KEXEC_MACH_TYPE] + ldr r2, [r7, #KEXEC_R2] + ARM( ret lr ) + THUMB( bx lr ) ENDPROC(relocate_new_kernel) + .align 3 relocate_new_kernel_end: .globl relocate_new_kernel_size |