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| 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/machine_kexec.c | |
| parent | 9c698bff66ab4914bb3d71da7dc6112519bde23e (diff) | |
| download | linux-4d62e81b60d4025e2dfcd5ea531cc1394ce9226f.tar.gz | |
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/machine_kexec.c')
| -rw-r--r-- | arch/arm/kernel/machine_kexec.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 5d84ad333f05..2b09dad7935e 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -13,6 +13,7 @@ #include <linux/of_fdt.h> #include <asm/mmu_context.h> #include <asm/cacheflush.h> +#include <asm/kexec-internal.h> #include <asm/fncpy.h> #include <asm/mach-types.h> #include <asm/smp_plat.h> @@ -22,11 +23,6 @@ extern void relocate_new_kernel(void); extern const unsigned int relocate_new_kernel_size; -extern unsigned long kexec_start_address; -extern unsigned long kexec_indirection_page; -extern unsigned long kexec_mach_type; -extern unsigned long kexec_boot_atags; - static atomic_t waiting_for_crash_ipi; /* @@ -159,6 +155,7 @@ void (*kexec_reinit)(void); void machine_kexec(struct kimage *image) { unsigned long page_list, reboot_entry_phys; + struct kexec_relocate_data *data; void (*reboot_entry)(void); void *reboot_code_buffer; @@ -174,18 +171,17 @@ void machine_kexec(struct kimage *image) reboot_code_buffer = page_address(image->control_code_page); - /* Prepare parameters for reboot_code_buffer*/ - set_kernel_text_rw(); - kexec_start_address = image->start; - kexec_indirection_page = page_list; - kexec_mach_type = machine_arch_type; - kexec_boot_atags = image->arch.kernel_r2; - /* copy our kernel relocation code to the control code page */ reboot_entry = fncpy(reboot_code_buffer, &relocate_new_kernel, relocate_new_kernel_size); + data = reboot_code_buffer + relocate_new_kernel_size; + data->kexec_start_address = image->start; + data->kexec_indirection_page = page_list; + data->kexec_mach_type = machine_arch_type; + data->kexec_r2 = image->arch.kernel_r2; + /* get the identity mapping physical address for the reboot code */ reboot_entry_phys = virt_to_idmap(reboot_entry); |