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-rw-r--r--arch/arm/Kconfig4
-rw-r--r--arch/arm/include/asm/assembler.h4
-rw-r--r--arch/arm/kernel/entry-armv.S54
-rw-r--r--arch/arm/kernel/irq.c23
-rw-r--r--arch/arm/kernel/traps.c15
-rw-r--r--arch/arm/lib/backtrace-clang.S8
-rw-r--r--arch/arm/lib/backtrace.S8
7 files changed, 112 insertions, 4 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4e301e4d2da6..b11846679cc6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1166,6 +1166,10 @@ config CURRENT_POINTER_IN_TPIDRURO
def_bool y
depends on SMP && CPU_32v6K && !CPU_V6
+config IRQSTACKS
+ def_bool y
+ depends on GENERIC_IRQ_MULTI_HANDLER && THREAD_INFO_IN_TASK
+
config ARM_CPU_TOPOLOGY
bool "Support cpu topology definition"
depends on SMP && CPU_V7
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 870bfaea4318..1b9d4df331aa 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -86,6 +86,10 @@
#define IMM12_MASK 0xfff
+/* the frame pointer used for stack unwinding */
+ARM( fpreg .req r11 )
+THUMB( fpreg .req r7 )
+
/*
* Enable and disable interrupts
*/
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index deff286eb5ea..1c7590eef712 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -36,10 +36,58 @@
/*
* Interrupt handling.
*/
- .macro irq_handler
+ .macro irq_handler, from_user:req
#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
mov r0, sp
+#ifdef CONFIG_IRQSTACKS
+ mov_l r2, irq_stack_ptr @ Take base address
+ mrc p15, 0, r3, c13, c0, 4 @ Get CPU offset
+#ifdef CONFIG_UNWINDER_ARM
+ mov fpreg, sp @ Preserve original SP
+#else
+ mov r8, fp @ Preserve original FP
+ mov r9, sp @ Preserve original SP
+#endif
+ ldr sp, [r2, r3] @ Load SP from per-CPU var
+ .if \from_user == 0
+UNWIND( .setfp fpreg, sp )
+ @
+ @ If we took the interrupt while running in the kernel, we may already
+ @ be using the IRQ stack, so revert to the original value in that case.
+ @
+ subs r2, sp, r0 @ SP above bottom of IRQ stack?
+ rsbscs r2, r2, #THREAD_SIZE @ ... and below the top?
+ movcs sp, r0 @ If so, revert to incoming SP
+
+#ifndef CONFIG_UNWINDER_ARM
+ @
+ @ Inform the frame pointer unwinder where the next frame lives
+ @
+ movcc lr, pc @ Make LR point into .entry.text so
+ @ that we will get a dump of the
+ @ exception stack for this frame.
+#ifdef CONFIG_CC_IS_GCC
+ movcc ip, r0 @ Store the old SP in the frame record.
+ stmdbcc sp!, {fp, ip, lr, pc} @ Push frame record
+ addcc fp, sp, #12
+#else
+ stmdbcc sp!, {fp, lr} @ Push frame record
+ movcc fp, sp
+#endif // CONFIG_CC_IS_GCC
+#endif // CONFIG_UNWINDER_ARM
+ .endif
+#endif // CONFIG_IRQSTACKS
+
bl generic_handle_arch_irq
+
+#ifdef CONFIG_IRQSTACKS
+#ifdef CONFIG_UNWINDER_ARM
+ mov sp, fpreg @ Restore original SP
+#else
+ mov fp, r8 @ Restore original FP
+ mov sp, r9 @ Restore original SP
+#endif // CONFIG_UNWINDER_ARM
+#endif // CONFIG_IRQSTACKS
#else
arch_irq_handler_default
#endif
@@ -199,7 +247,7 @@ ENDPROC(__dabt_svc)
.align 5
__irq_svc:
svc_entry
- irq_handler
+ irq_handler from_user=0
#ifdef CONFIG_PREEMPTION
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
@@ -426,7 +474,7 @@ ENDPROC(__dabt_usr)
__irq_usr:
usr_entry
kuser_cmpxchg_check
- irq_handler
+ irq_handler from_user=1
get_thread_info tsk
mov why, #0
b ret_to_user_from_irq
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index b79975bd988c..abb0aa679bba 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -43,6 +43,25 @@
unsigned long irq_err_count;
+#ifdef CONFIG_IRQSTACKS
+
+asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr);
+
+static void __init init_irq_stacks(void)
+{
+ u8 *stack;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ stack = (u8 *)__get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
+ if (WARN_ON(!stack))
+ break;
+ per_cpu(irq_stack_ptr, cpu) = &stack[THREAD_SIZE];
+ }
+}
+
+#endif
+
int arch_show_interrupts(struct seq_file *p, int prec)
{
#ifdef CONFIG_FIQ
@@ -101,6 +120,10 @@ void __init init_IRQ(void)
{
int ret;
+#ifdef CONFIG_IRQSTACKS
+ init_irq_stacks();
+#endif
+
if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
irqchip_init();
else
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 89be21ec3b52..b42c446cec9a 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -66,6 +66,19 @@ void dump_backtrace_entry(unsigned long where, unsigned long from,
{
unsigned long end = frame + 4 + sizeof(struct pt_regs);
+ if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER) &&
+ IS_ENABLED(CONFIG_CC_IS_GCC) &&
+ end > ALIGN(frame, THREAD_SIZE)) {
+ /*
+ * If we are walking past the end of the stack, it may be due
+ * to the fact that we are on an IRQ or overflow stack. In this
+ * case, we can load the address of the other stack from the
+ * frame record.
+ */
+ frame = ((unsigned long *)frame)[-2] - 4;
+ end = frame + 4 + sizeof(struct pt_regs);
+ }
+
#ifdef CONFIG_KALLSYMS
printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n",
loglvl, where, (void *)where, from, (void *)from);
@@ -278,7 +291,7 @@ static int __die(const char *str, int err, struct pt_regs *regs)
if (!user_mode(regs) || in_interrupt()) {
dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
- THREAD_SIZE + (unsigned long)task_stack_page(tsk));
+ ALIGN(regs->ARM_sp, THREAD_SIZE));
dump_backtrace(regs, tsk, KERN_EMERG);
dump_instr(KERN_EMERG, regs);
}
diff --git a/arch/arm/lib/backtrace-clang.S b/arch/arm/lib/backtrace-clang.S
index 5b4bca85d06d..290c52a60fc6 100644
--- a/arch/arm/lib/backtrace-clang.S
+++ b/arch/arm/lib/backtrace-clang.S
@@ -197,6 +197,14 @@ finished_setup:
cmp sv_fp, frame @ next frame must be
mov frame, sv_fp @ above the current frame
+#ifdef CONFIG_IRQSTACKS
+ @
+ @ Kernel stacks may be discontiguous in memory. If the next
+ @ frame is below the previous frame, accept it as long as it
+ @ lives in kernel memory.
+ @
+ cmpls sv_fp, #PAGE_OFFSET
+#endif
bhi for_each_frame
1006: adr r0, .Lbad
diff --git a/arch/arm/lib/backtrace.S b/arch/arm/lib/backtrace.S
index e8408f22d4dc..293a2716bd20 100644
--- a/arch/arm/lib/backtrace.S
+++ b/arch/arm/lib/backtrace.S
@@ -98,6 +98,14 @@ for_each_frame: tst frame, mask @ Check for address exceptions
cmp sv_fp, frame @ next frame must be
mov frame, sv_fp @ above the current frame
+#ifdef CONFIG_IRQSTACKS
+ @
+ @ Kernel stacks may be discontiguous in memory. If the next
+ @ frame is below the previous frame, accept it as long as it
+ @ lives in kernel memory.
+ @
+ cmpls sv_fp, #PAGE_OFFSET
+#endif
bhi for_each_frame
1006: adr r0, .Lbad
generated by cgit (git 2.34.1) at 2024-05-17 11:00:31 +0000