lkml.org 
[lkml]   [2022]   [Jul]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v4 01/18] arm64: stacktrace: Add shared header for common stack unwinding code
    Hi,

    Can you please explain why you are targetting my @oracle.com email
    address with this patch set?

    This causes me problems as I use Outlook's Web interface for that
    which doesn't appear to cope with the threading, and most certainly
    is only capable of top-reply only which is against Linux kernel email
    standards.

    Thanks.

    On Thu, Jul 14, 2022 at 11:10:10PM -0700, Kalesh Singh wrote:
    > In order to reuse the arm64 stack unwinding logic for the nVHE
    > hypervisor stack, move the common code to a shared header
    > (arch/arm64/include/asm/stacktrace/common.h).
    >
    > The nVHE hypervisor cannot safely link against kernel code, so we
    > make use of the shared header to avoid duplicated logic later in
    > this series.
    >
    > Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
    > ---
    > arch/arm64/include/asm/stacktrace.h | 35 +------
    > arch/arm64/include/asm/stacktrace/common.h | 105 +++++++++++++++++++++
    > arch/arm64/kernel/stacktrace.c | 57 -----------
    > 3 files changed, 106 insertions(+), 91 deletions(-)
    > create mode 100644 arch/arm64/include/asm/stacktrace/common.h
    >
    > diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
    > index aec9315bf156..79f455b37c84 100644
    > --- a/arch/arm64/include/asm/stacktrace.h
    > +++ b/arch/arm64/include/asm/stacktrace.h
    > @@ -8,52 +8,19 @@
    > #include <linux/percpu.h>
    > #include <linux/sched.h>
    > #include <linux/sched/task_stack.h>
    > -#include <linux/types.h>
    > #include <linux/llist.h>
    >
    > #include <asm/memory.h>
    > #include <asm/ptrace.h>
    > #include <asm/sdei.h>
    >
    > -enum stack_type {
    > - STACK_TYPE_UNKNOWN,
    > - STACK_TYPE_TASK,
    > - STACK_TYPE_IRQ,
    > - STACK_TYPE_OVERFLOW,
    > - STACK_TYPE_SDEI_NORMAL,
    > - STACK_TYPE_SDEI_CRITICAL,
    > - __NR_STACK_TYPES
    > -};
    > -
    > -struct stack_info {
    > - unsigned long low;
    > - unsigned long high;
    > - enum stack_type type;
    > -};
    > +#include <asm/stacktrace/common.h>
    >
    > extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
    > const char *loglvl);
    >
    > DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
    >
    > -static inline bool on_stack(unsigned long sp, unsigned long size,
    > - unsigned long low, unsigned long high,
    > - enum stack_type type, struct stack_info *info)
    > -{
    > - if (!low)
    > - return false;
    > -
    > - if (sp < low || sp + size < sp || sp + size > high)
    > - return false;
    > -
    > - if (info) {
    > - info->low = low;
    > - info->high = high;
    > - info->type = type;
    > - }
    > - return true;
    > -}
    > -
    > static inline bool on_irq_stack(unsigned long sp, unsigned long size,
    > struct stack_info *info)
    > {
    > diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
    > new file mode 100644
    > index 000000000000..64ae4f6b06fe
    > --- /dev/null
    > +++ b/arch/arm64/include/asm/stacktrace/common.h
    > @@ -0,0 +1,105 @@
    > +/* SPDX-License-Identifier: GPL-2.0-only */
    > +/*
    > + * Common arm64 stack unwinder code.
    > + *
    > + * Copyright (C) 2012 ARM Ltd.
    > + */
    > +#ifndef __ASM_STACKTRACE_COMMON_H
    > +#define __ASM_STACKTRACE_COMMON_H
    > +
    > +#include <linux/bitmap.h>
    > +#include <linux/bitops.h>
    > +#include <linux/types.h>
    > +
    > +enum stack_type {
    > + STACK_TYPE_UNKNOWN,
    > + STACK_TYPE_TASK,
    > + STACK_TYPE_IRQ,
    > + STACK_TYPE_OVERFLOW,
    > + STACK_TYPE_SDEI_NORMAL,
    > + STACK_TYPE_SDEI_CRITICAL,
    > + __NR_STACK_TYPES
    > +};
    > +
    > +struct stack_info {
    > + unsigned long low;
    > + unsigned long high;
    > + enum stack_type type;
    > +};
    > +
    > +/*
    > + * A snapshot of a frame record or fp/lr register values, along with some
    > + * accounting information necessary for robust unwinding.
    > + *
    > + * @fp: The fp value in the frame record (or the real fp)
    > + * @pc: The lr value in the frame record (or the real lr)
    > + *
    > + * @stacks_done: Stacks which have been entirely unwound, for which it is no
    > + * longer valid to unwind to.
    > + *
    > + * @prev_fp: The fp that pointed to this frame record, or a synthetic value
    > + * of 0. This is used to ensure that within a stack, each
    > + * subsequent frame record is at an increasing address.
    > + * @prev_type: The type of stack this frame record was on, or a synthetic
    > + * value of STACK_TYPE_UNKNOWN. This is used to detect a
    > + * transition from one stack to another.
    > + *
    > + * @kr_cur: When KRETPROBES is selected, holds the kretprobe instance
    > + * associated with the most recently encountered replacement lr
    > + * value.
    > + *
    > + * @task: The task being unwound.
    > + */
    > +struct unwind_state {
    > + unsigned long fp;
    > + unsigned long pc;
    > + DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
    > + unsigned long prev_fp;
    > + enum stack_type prev_type;
    > +#ifdef CONFIG_KRETPROBES
    > + struct llist_node *kr_cur;
    > +#endif
    > + struct task_struct *task;
    > +};
    > +
    > +static inline bool on_stack(unsigned long sp, unsigned long size,
    > + unsigned long low, unsigned long high,
    > + enum stack_type type, struct stack_info *info)
    > +{
    > + if (!low)
    > + return false;
    > +
    > + if (sp < low || sp + size < sp || sp + size > high)
    > + return false;
    > +
    > + if (info) {
    > + info->low = low;
    > + info->high = high;
    > + info->type = type;
    > + }
    > + return true;
    > +}
    > +
    > +static inline void unwind_init_common(struct unwind_state *state,
    > + struct task_struct *task)
    > +{
    > + state->task = task;
    > +#ifdef CONFIG_KRETPROBES
    > + state->kr_cur = NULL;
    > +#endif
    > +
    > + /*
    > + * Prime the first unwind.
    > + *
    > + * In unwind_next() we'll check that the FP points to a valid stack,
    > + * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
    > + * treated as a transition to whichever stack that happens to be. The
    > + * prev_fp value won't be used, but we set it to 0 such that it is
    > + * definitely not an accessible stack address.
    > + */
    > + bitmap_zero(state->stacks_done, __NR_STACK_TYPES);
    > + state->prev_fp = 0;
    > + state->prev_type = STACK_TYPE_UNKNOWN;
    > +}
    > +
    > +#endif /* __ASM_STACKTRACE_COMMON_H */
    > diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
    > index fcaa151b81f1..94a5dd2ab8fd 100644
    > --- a/arch/arm64/kernel/stacktrace.c
    > +++ b/arch/arm64/kernel/stacktrace.c
    > @@ -18,63 +18,6 @@
    > #include <asm/stack_pointer.h>
    > #include <asm/stacktrace.h>
    >
    > -/*
    > - * A snapshot of a frame record or fp/lr register values, along with some
    > - * accounting information necessary for robust unwinding.
    > - *
    > - * @fp: The fp value in the frame record (or the real fp)
    > - * @pc: The lr value in the frame record (or the real lr)
    > - *
    > - * @stacks_done: Stacks which have been entirely unwound, for which it is no
    > - * longer valid to unwind to.
    > - *
    > - * @prev_fp: The fp that pointed to this frame record, or a synthetic value
    > - * of 0. This is used to ensure that within a stack, each
    > - * subsequent frame record is at an increasing address.
    > - * @prev_type: The type of stack this frame record was on, or a synthetic
    > - * value of STACK_TYPE_UNKNOWN. This is used to detect a
    > - * transition from one stack to another.
    > - *
    > - * @kr_cur: When KRETPROBES is selected, holds the kretprobe instance
    > - * associated with the most recently encountered replacement lr
    > - * value.
    > - *
    > - * @task: The task being unwound.
    > - */
    > -struct unwind_state {
    > - unsigned long fp;
    > - unsigned long pc;
    > - DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
    > - unsigned long prev_fp;
    > - enum stack_type prev_type;
    > -#ifdef CONFIG_KRETPROBES
    > - struct llist_node *kr_cur;
    > -#endif
    > - struct task_struct *task;
    > -};
    > -
    > -static void unwind_init_common(struct unwind_state *state,
    > - struct task_struct *task)
    > -{
    > - state->task = task;
    > -#ifdef CONFIG_KRETPROBES
    > - state->kr_cur = NULL;
    > -#endif
    > -
    > - /*
    > - * Prime the first unwind.
    > - *
    > - * In unwind_next() we'll check that the FP points to a valid stack,
    > - * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
    > - * treated as a transition to whichever stack that happens to be. The
    > - * prev_fp value won't be used, but we set it to 0 such that it is
    > - * definitely not an accessible stack address.
    > - */
    > - bitmap_zero(state->stacks_done, __NR_STACK_TYPES);
    > - state->prev_fp = 0;
    > - state->prev_type = STACK_TYPE_UNKNOWN;
    > -}
    > -
    > /*
    > * Start an unwind from a pt_regs.
    > *
    > --
    > 2.37.0.170.g444d1eabd0-goog
    >
    >
    > _______________________________________________
    > linux-arm-kernel mailing list
    > linux-arm-kernel@lists.infradead.org
    > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
    >

    --
    RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
    FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

    \
     
     \ /
      Last update: 2022-07-18 14:54    [W:2.732 / U:0.440 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site