From 4d62e81b60d4025e2dfcd5ea531cc1394ce9226f Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 1 Feb 2021 19:40:01 +0000 Subject: 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 Tested-by: Giancarlo Ferrari Signed-off-by: Russell King --- arch/arm/kernel/asm-offsets.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/arm/kernel/asm-offsets.c') diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index a1570c8bab25..be8050b0c3df 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -170,5 +171,9 @@ int main(void) DEFINE(MPU_RGN_PRBAR, offsetof(struct mpu_rgn, prbar)); DEFINE(MPU_RGN_PRLAR, offsetof(struct mpu_rgn, prlar)); #endif + DEFINE(KEXEC_START_ADDR, offsetof(struct kexec_relocate_data, kexec_start_address)); + DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page)); + DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type)); + DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2)); return 0; } -- cgit v1.2.3