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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 18:50:40 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 18:50:59 +0000 |
| commit | ba6b167af6ee5e63ca79ad22e7719644aed12b2c (patch) | |
| tree | 62272cbe2fb256ecb90fa6e2cbfa509541954d28 /debian/patches-rt/arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch | |
| parent | Merging upstream version 6.8.9. (diff) | |
| download | linux-ba6b167af6ee5e63ca79ad22e7719644aed12b2c.tar.xz linux-ba6b167af6ee5e63ca79ad22e7719644aed12b2c.zip | |
Merging debian version 6.8.9-1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/debian/patches-rt/arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch b/debian/patches-rt/arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch new file mode 100644 index 0000000000..09dcd78d53 --- /dev/null +++ b/debian/patches-rt/arm-Disable-FAST_GUP-on-PREEMPT_RT-if-HIGHPTE-is-als.patch @@ -0,0 +1,35 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Tue, 23 Jan 2024 12:56:21 +0100 +Subject: [PATCH] arm: Disable FAST_GUP on PREEMPT_RT if HIGHPTE is also + enabled. +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz + +gup_pgd_range() is invoked with disabled interrupts and invokes +__kmap_local_page_prot() via pte_offset_map(), gup_p4d_range(). +With HIGHPTE enabled, __kmap_local_page_prot() invokes kmap_high_get() +which uses a spinlock_t via lock_kmap_any(). This leads to an +sleeping-while-atomic error on PREEMPT_RT because spinlock_t becomes a +sleeping lock and must not be acquired in atomic context. + +The loop in map_new_virtual() uses wait_queue_head_t for wake up which +also is using a spinlock_t. + +Limit HAVE_FAST_GUP additionaly to remain disabled on PREEMPT_RT with +HIGHPTE enabled. + +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + arch/arm/Kconfig | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/arch/arm/Kconfig ++++ b/arch/arm/Kconfig +@@ -98,7 +98,7 @@ config ARM + select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE + select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU + select HAVE_EXIT_THREAD +- select HAVE_FAST_GUP if ARM_LPAE ++ select HAVE_FAST_GUP if ARM_LPAE && !(PREEMPT_RT && HIGHPTE) + select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL + select HAVE_FUNCTION_ERROR_INJECTION + select HAVE_FUNCTION_GRAPH_TRACER |