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-rw-r--r--arch/powerpc/include/asm/hvcall.h3
-rw-r--r--arch/powerpc/include/asm/interrupt.h9
-rw-r--r--arch/powerpc/include/asm/paravirt.h22
-rw-r--r--arch/powerpc/include/asm/plpar_wrappers.h6
-rw-r--r--arch/powerpc/include/asm/ptrace.h45
-rw-r--r--arch/powerpc/include/asm/syscall.h42
-rw-r--r--arch/powerpc/include/asm/uaccess.h2
7 files changed, 87 insertions, 42 deletions
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 443050906018..e3b29eda8074 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -448,6 +448,9 @@
*/
long plpar_hcall_norets(unsigned long opcode, ...);
+/* Variant which does not do hcall tracing */
+long plpar_hcall_norets_notrace(unsigned long opcode, ...);
+
/**
* plpar_hcall: - Make a pseries hypervisor call
* @opcode: The hypervisor call to make.
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 44cde2e129b8..59f704408d65 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -153,8 +153,6 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
*/
static inline void interrupt_exit_prepare(struct pt_regs *regs, struct interrupt_state *state)
{
- if (user_mode(regs))
- kuep_unlock();
}
static inline void interrupt_async_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)
@@ -222,6 +220,13 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
local_paca->irq_soft_mask = IRQS_ALL_DISABLED;
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+ if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !(regs->msr & MSR_PR) &&
+ regs->nip < (unsigned long)__end_interrupts) {
+ // Kernel code running below __end_interrupts is
+ // implicitly soft-masked.
+ regs->softe = IRQS_ALL_DISABLED;
+ }
+
/* Don't do any per-CPU operations until interrupt state is fixed */
if (nmi_disables_ftrace(regs)) {
diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h
index 5d1726bb28e7..bcb7b5f917be 100644
--- a/arch/powerpc/include/asm/paravirt.h
+++ b/arch/powerpc/include/asm/paravirt.h
@@ -28,19 +28,35 @@ static inline u32 yield_count_of(int cpu)
return be32_to_cpu(yield_count);
}
+/*
+ * Spinlock code confers and prods, so don't trace the hcalls because the
+ * tracing code takes spinlocks which can cause recursion deadlocks.
+ *
+ * These calls are made while the lock is not held: the lock slowpath yields if
+ * it can not acquire the lock, and unlock slow path might prod if a waiter has
+ * yielded). So this may not be a problem for simple spin locks because the
+ * tracing does not technically recurse on the lock, but we avoid it anyway.
+ *
+ * However the queued spin lock contended path is more strictly ordered: the
+ * H_CONFER hcall is made after the task has queued itself on the lock, so then
+ * recursing on that lock will cause the task to then queue up again behind the
+ * first instance (or worse: queued spinlocks use tricks that assume a context
+ * never waits on more than one spinlock, so such recursion may cause random
+ * corruption in the lock code).
+ */
static inline void yield_to_preempted(int cpu, u32 yield_count)
{
- plpar_hcall_norets(H_CONFER, get_hard_smp_processor_id(cpu), yield_count);
+ plpar_hcall_norets_notrace(H_CONFER, get_hard_smp_processor_id(cpu), yield_count);
}
static inline void prod_cpu(int cpu)
{
- plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
+ plpar_hcall_norets_notrace(H_PROD, get_hard_smp_processor_id(cpu));
}
static inline void yield_to_any(void)
{
- plpar_hcall_norets(H_CONFER, -1, 0);
+ plpar_hcall_norets_notrace(H_CONFER, -1, 0);
}
#else
static inline bool is_shared_processor(void)
diff --git a/arch/powerpc/include/asm/plpar_wrappers.h b/arch/powerpc/include/asm/plpar_wrappers.h
index ece84a430701..83e0f701ebc6 100644
--- a/arch/powerpc/include/asm/plpar_wrappers.h
+++ b/arch/powerpc/include/asm/plpar_wrappers.h
@@ -28,7 +28,11 @@ static inline void set_cede_latency_hint(u8 latency_hint)
static inline long cede_processor(void)
{
- return plpar_hcall_norets(H_CEDE);
+ /*
+ * We cannot call tracepoints inside RCU idle regions which
+ * means we must not trace H_CEDE.
+ */
+ return plpar_hcall_norets_notrace(H_CEDE);
}
static inline long extended_cede_processor(unsigned long latency_hint)
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 9c9ab2746168..b476a685f066 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -19,6 +19,7 @@
#ifndef _ASM_POWERPC_PTRACE_H
#define _ASM_POWERPC_PTRACE_H
+#include <linux/err.h>
#include <uapi/asm/ptrace.h>
#include <asm/asm-const.h>
@@ -152,25 +153,6 @@ extern unsigned long profile_pc(struct pt_regs *regs);
long do_syscall_trace_enter(struct pt_regs *regs);
void do_syscall_trace_leave(struct pt_regs *regs);
-#define kernel_stack_pointer(regs) ((regs)->gpr[1])
-static inline int is_syscall_success(struct pt_regs *regs)
-{
- return !(regs->ccr & 0x10000000);
-}
-
-static inline long regs_return_value(struct pt_regs *regs)
-{
- if (is_syscall_success(regs))
- return regs->gpr[3];
- else
- return -regs->gpr[3];
-}
-
-static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
-{
- regs->gpr[3] = rc;
-}
-
#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
@@ -235,6 +217,31 @@ static __always_inline void set_trap_norestart(struct pt_regs *regs)
regs->trap |= 0x1;
}
+#define kernel_stack_pointer(regs) ((regs)->gpr[1])
+static inline int is_syscall_success(struct pt_regs *regs)
+{
+ if (trap_is_scv(regs))
+ return !IS_ERR_VALUE((unsigned long)regs->gpr[3]);
+ else
+ return !(regs->ccr & 0x10000000);
+}
+
+static inline long regs_return_value(struct pt_regs *regs)
+{
+ if (trap_is_scv(regs))
+ return regs->gpr[3];
+
+ if (is_syscall_success(regs))
+ return regs->gpr[3];
+ else
+ return -regs->gpr[3];
+}
+
+static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
+{
+ regs->gpr[3] = rc;
+}
+
#define arch_has_single_step() (1)
#define arch_has_block_step() (true)
#define ARCH_HAS_USER_SINGLE_STEP_REPORT
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index fd1b518eed17..ba0f88f3a30d 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -41,11 +41,17 @@ static inline void syscall_rollback(struct task_struct *task,
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
- /*
- * If the system call failed,
- * regs->gpr[3] contains a positive ERRORCODE.
- */
- return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
+ if (trap_is_scv(regs)) {
+ unsigned long error = regs->gpr[3];
+
+ return IS_ERR_VALUE(error) ? error : 0;
+ } else {
+ /*
+ * If the system call failed,
+ * regs->gpr[3] contains a positive ERRORCODE.
+ */
+ return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
+ }
}
static inline long syscall_get_return_value(struct task_struct *task,
@@ -58,18 +64,22 @@ static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
- /*
- * In the general case it's not obvious that we must deal with CCR
- * here, as the syscall exit path will also do that for us. However
- * there are some places, eg. the signal code, which check ccr to
- * decide if the value in r3 is actually an error.
- */
- if (error) {
- regs->ccr |= 0x10000000L;
- regs->gpr[3] = error;
+ if (trap_is_scv(regs)) {
+ regs->gpr[3] = (long) error ?: val;
} else {
- regs->ccr &= ~0x10000000L;
- regs->gpr[3] = val;
+ /*
+ * In the general case it's not obvious that we must deal with
+ * CCR here, as the syscall exit path will also do that for us.
+ * However there are some places, eg. the signal code, which
+ * check ccr to decide if the value in r3 is actually an error.
+ */
+ if (error) {
+ regs->ccr |= 0x10000000L;
+ regs->gpr[3] = error;
+ } else {
+ regs->ccr &= ~0x10000000L;
+ regs->gpr[3] = val;
+ }
}
}
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index a09e4240c5b1..22c79ab40006 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -157,7 +157,7 @@ do { \
"2: lwz%X1 %L0, %L1\n" \
EX_TABLE(1b, %l2) \
EX_TABLE(2b, %l2) \
- : "=r" (x) \
+ : "=&r" (x) \
: "m" (*addr) \
: \
: label)
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-12 03:30:15 +0300