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authorLinus Torvalds <torvalds@linux-foundation.org>2023-01-23 11:46:19 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-01-23 11:46:19 -0800
commit9946f0981ff8698848ee79d739f432a2a3e68eed (patch)
tree993b08569f46b2bd1a478b5beee510ae21ffa1a6 /arch
parent2475bf0250dee99b477e0c56d7dc9d7ac3f04117 (diff)
parente1fabbc83cb1dd4ba63932faa86c9cacb8bf791e (diff)
Merge tag 'efi-fixes-for-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI fixes from Ard Biesheuvel: "Another couple of EFI fixes, of which the first two were already in -next when I sent out the previous PR, but they caused some issues on non-EFI boots so I let them simmer for a bit longer. - ensure the EFI ResetSystem and ACPI PRM calls are recognized as users of the EFI runtime, and therefore protected against exceptions - account for the EFI runtime stack in the stacktrace code - remove Matthew Garrett's MAINTAINERS entry for efivarfs" * tag 'efi-fixes-for-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: Remove Matthew Garrett as efivarfs maintainer arm64: efi: Account for the EFI runtime stack in stack unwinder arm64: efi: Avoid workqueue to check whether EFI runtime is live
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/efi.h9
-rw-r--r--arch/arm64/include/asm/stacktrace.h15
-rw-r--r--arch/arm64/kernel/efi-rt-wrapper.S6
-rw-r--r--arch/arm64/kernel/efi.c3
-rw-r--r--arch/arm64/kernel/stacktrace.c12
5 files changed, 44 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 31d13a6001df..de4ff90785b2 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -48,8 +48,17 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
})
extern spinlock_t efi_rt_lock;
+extern u64 *efi_rt_stack_top;
efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
+/*
+ * efi_rt_stack_top[-1] contains the value the stack pointer had before
+ * switching to the EFI runtime stack.
+ */
+#define current_in_efi() \
+ (!preemptible() && efi_rt_stack_top != NULL && \
+ on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1))
+
#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
/*
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 4e5354beafb0..66ec8caa6ac0 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -106,4 +106,19 @@ static inline struct stack_info stackinfo_get_sdei_critical(void)
#define stackinfo_get_sdei_critical() stackinfo_get_unknown()
#endif
+#ifdef CONFIG_EFI
+extern u64 *efi_rt_stack_top;
+
+static inline struct stack_info stackinfo_get_efi(void)
+{
+ unsigned long high = (u64)efi_rt_stack_top;
+ unsigned long low = high - THREAD_SIZE;
+
+ return (struct stack_info) {
+ .low = low,
+ .high = high,
+ };
+}
+#endif
+
#endif /* __ASM_STACKTRACE_H */
diff --git a/arch/arm64/kernel/efi-rt-wrapper.S b/arch/arm64/kernel/efi-rt-wrapper.S
index d872d18101d8..e8ae803662cf 100644
--- a/arch/arm64/kernel/efi-rt-wrapper.S
+++ b/arch/arm64/kernel/efi-rt-wrapper.S
@@ -46,7 +46,10 @@ SYM_FUNC_START(__efi_rt_asm_wrapper)
mov x4, x6
blr x8
+ mov x16, sp
mov sp, x29
+ str xzr, [x16, #8] // clear recorded task SP value
+
ldp x1, x2, [sp, #16]
cmp x2, x18
ldp x29, x30, [sp], #112
@@ -71,6 +74,9 @@ SYM_FUNC_END(__efi_rt_asm_wrapper)
SYM_CODE_START(__efi_rt_asm_recover)
mov sp, x30
+ ldr_l x16, efi_rt_stack_top // clear recorded task SP value
+ str xzr, [x16, #-8]
+
ldp x19, x20, [sp, #32]
ldp x21, x22, [sp, #48]
ldp x23, x24, [sp, #64]
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index fab05de2e12d..b273900f4566 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <asm/efi.h>
+#include <asm/stacktrace.h>
static bool region_is_misaligned(const efi_memory_desc_t *md)
{
@@ -154,7 +155,7 @@ asmlinkage efi_status_t __efi_rt_asm_recover(void);
bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg)
{
/* Check whether the exception occurred while running the firmware */
- if (current_work() != &efi_rts_work.work || regs->pc >= TASK_SIZE_64)
+ if (!current_in_efi() || regs->pc >= TASK_SIZE_64)
return false;
pr_err(FW_BUG "Unable to handle %s in EFI runtime service\n", msg);
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 117e2c180f3c..83154303e682 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -5,6 +5,7 @@
* Copyright (C) 2012 ARM Ltd.
*/
#include <linux/kernel.h>
+#include <linux/efi.h>
#include <linux/export.h>
#include <linux/ftrace.h>
#include <linux/sched.h>
@@ -12,6 +13,7 @@
#include <linux/sched/task_stack.h>
#include <linux/stacktrace.h>
+#include <asm/efi.h>
#include <asm/irq.h>
#include <asm/stack_pointer.h>
#include <asm/stacktrace.h>
@@ -186,6 +188,13 @@ void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
: stackinfo_get_unknown(); \
})
+#define STACKINFO_EFI \
+ ({ \
+ ((task == current) && current_in_efi()) \
+ ? stackinfo_get_efi() \
+ : stackinfo_get_unknown(); \
+ })
+
noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry,
void *cookie, struct task_struct *task,
struct pt_regs *regs)
@@ -200,6 +209,9 @@ noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry,
STACKINFO_SDEI(normal),
STACKINFO_SDEI(critical),
#endif
+#ifdef CONFIG_EFI
+ STACKINFO_EFI,
+#endif
};
struct unwind_state state = {
.stacks = stacks,