From: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>
To: linux@armlinux.org.uk
Cc: giancarlo.ferrari@nokia.com, michal.simek@xilinx.com,
Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] ARM: kexec: Fix panic after TLB are invalidated
Date: Tue, 12 Jan 2021 16:49:06 +0000 [thread overview]
Message-ID: <1610470147-22641-1-git-send-email-giancarlo.ferrari89@gmail.com> (raw)
machine_kexec() need to set rw permission in text and rodata sections
to assign some variables (e.g. kexec_start_address). To do that at
the end (after flushing pdm in memory, inv D-Cache, etc.) it needs to
invalidate TLB [section] entries.
If during the TLB invalidation an interrupt occours, which might cause
a context switch, there is the risk to inject invalid TLBs, with ro
permissions.
When trying to assign .text labels, this lead to the following issue:
"Unable to handle kernel paging request at virtual address <valid_addr>"
with FSR 0x80d.
Signed-off-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>
---
arch/arm/kernel/machine_kexec.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
index 76300f3..bbe912d 100644
--- a/arch/arm/kernel/machine_kexec.c
+++ b/arch/arm/kernel/machine_kexec.c
@@ -176,6 +176,13 @@ void machine_kexec(struct kimage *image)
reboot_code_buffer = page_address(image->control_code_page);
+ /*
+ * If below part is not atomic TLB entries might be corrupted after TLB
+ * invalidation, which leads to Data Abort in .text variable assignment
+ */
+ raw_local_irq_disable();
+ local_fiq_disable();
+
/* Prepare parameters for reboot_code_buffer*/
set_kernel_text_rw();
kexec_start_address = image->start;
@@ -183,6 +190,9 @@ void machine_kexec(struct kimage *image)
kexec_mach_type = machine_arch_type;
kexec_boot_atags = image->arch.kernel_r2;
+ local_fiq_enable();
+ raw_local_irq_enable();
+
/* copy our kernel relocation code to the control code page */
reboot_entry = fncpy(reboot_code_buffer,
&relocate_new_kernel,
--
2.7.4
next reply other threads:[~2021-01-12 16:52 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 16:49 Giancarlo Ferrari [this message]
2021-02-01 10:10 ` [PATCH] ARM: kexec: Fix panic after TLB are invalidated Giancarlo Ferrari
2021-02-01 0:44 Giancarlo Ferrari
2021-02-01 11:34 ` Russell King - ARM Linux admin
2021-02-01 12:47 ` Mark Rutland
2021-02-01 13:03 ` Russell King - ARM Linux admin
2021-02-01 13:57 ` Mark Rutland
2021-02-01 16:08 ` Russell King - ARM Linux admin
2021-02-01 16:32 ` Mark Rutland
2021-02-01 16:37 ` Russell King - ARM Linux admin
2021-02-01 20:07 ` Giancarlo Ferrari
2021-02-01 20:16 ` Russell King - ARM Linux admin
2021-02-01 22:18 ` Giancarlo Ferrari
2021-02-04 23:48 ` Giancarlo Ferrari
2021-02-05 0:18 ` Russell King - ARM Linux admin
2021-02-05 0:40 ` Giancarlo Ferrari
2021-02-05 0:45 ` Giancarlo Ferrari
2021-02-05 9:44 ` Russell King - ARM Linux admin
2021-02-05 14:36 ` Giancarlo Ferrari
2021-02-01 14:39 ` Giancarlo Ferrari
2021-02-01 15:30 ` Mark Rutland
2021-02-01 19:09 ` Giancarlo Ferrari
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