Re: [PATCH v5 1/6] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature

From: Masami Hiramatsu
Date: Wed Feb 18 2015 - 09:59:28 EST

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(2015/02/18 8:11), David Long wrote:
> From: "David A. Long" <dave.long@xxxxxxxxxx>
>
> Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64.
>
> Signed-off-by: David A. Long <dave.long@xxxxxxxxxx>

Looks good to me,

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>

Thanks,

> ---
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/ptrace.h | 29 +++++++++
> arch/arm64/include/uapi/asm/ptrace.h | 36 +++++++++++
> arch/arm64/kernel/ptrace.c | 116 +++++++++++++++++++++++++++++++++++
> 4 files changed, 182 insertions(+)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index b1f9a20..12b3fd6 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -64,6 +64,7 @@ config ARM64
> select HAVE_PERF_EVENTS
> select HAVE_PERF_REGS
> select HAVE_PERF_USER_STACK_DUMP
> + select HAVE_REGS_AND_STACK_ACCESS_API
> select HAVE_RCU_TABLE_FREE
> select HAVE_SYSCALL_TRACEPOINTS
> select IRQ_DOMAIN
> diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
> index 41ed9e1..3613e49 100644
> --- a/arch/arm64/include/asm/ptrace.h
> +++ b/arch/arm64/include/asm/ptrace.h
> @@ -111,6 +111,8 @@ struct pt_regs {
> u64 syscallno;
> };
>
> +#define MAX_REG_OFFSET (sizeof(struct user_pt_regs) - sizeof(u64))
> +
> #define arch_has_single_step() (1)
>
> #ifdef CONFIG_COMPAT
> @@ -139,11 +141,38 @@ struct pt_regs {
> #define user_stack_pointer(regs) \
> (!compat_user_mode(regs) ? (regs)->sp : (regs)->compat_sp)
>
> +/**
> + * regs_get_register() - get register value from its offset
> + * @regs: pt_regs from which register value is gotten
> + * @offset: offset number of the register.
> + *
> + * regs_get_register returns the value of a register whose offset from @regs.
> + * The @offset is the offset of the register in struct pt_regs.
> + * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
> + */
> +static inline u64 regs_get_register(struct pt_regs *regs,
> + unsigned int offset)
> +{
> + if (unlikely(offset > MAX_REG_OFFSET))
> + return 0;
> + return *(u64 *)((u64)regs + offset);
> +}
> +
> +/* Valid only for Kernel mode traps. */
> +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
> +{
> + return regs->ARM_sp;
> +}
> +
> static inline unsigned long regs_return_value(struct pt_regs *regs)
> {
> return regs->regs[0];
> }
>
> +extern int regs_query_register_offset(const char *name);
> +extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
> + unsigned int n);
> +
> /*
> * Are the current registers suitable for user mode? (used to maintain
> * security in signal handlers)
> diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h
> index 6913643..700d28b 100644
> --- a/arch/arm64/include/uapi/asm/ptrace.h
> +++ b/arch/arm64/include/uapi/asm/ptrace.h
> @@ -61,6 +61,42 @@
>
> #ifndef __ASSEMBLY__
>
> +#define ARM_cpsr pstate
> +#define ARM_pc pc
> +#define ARM_sp sp
> +#define ARM_lr regs[30]
> +#define ARM_fp regs[29]
> +#define ARM_x28 regs[28]
> +#define ARM_x27 regs[27]
> +#define ARM_x26 regs[26]
> +#define ARM_x25 regs[25]
> +#define ARM_x24 regs[24]
> +#define ARM_x23 regs[23]
> +#define ARM_x22 regs[22]
> +#define ARM_x21 regs[21]
> +#define ARM_x20 regs[20]
> +#define ARM_x19 regs[19]
> +#define ARM_x18 regs[18]
> +#define ARM_ip1 regs[17]
> +#define ARM_ip0 regs[16]
> +#define ARM_x15 regs[15]
> +#define ARM_x14 regs[14]
> +#define ARM_x13 regs[13]
> +#define ARM_x12 regs[12]
> +#define ARM_x11 regs[11]
> +#define ARM_x10 regs[10]
> +#define ARM_x9 regs[9]
> +#define ARM_x8 regs[8]
> +#define ARM_x7 regs[7]
> +#define ARM_x6 regs[6]
> +#define ARM_x5 regs[5]
> +#define ARM_x4 regs[4]
> +#define ARM_x3 regs[3]
> +#define ARM_x2 regs[2]
> +#define ARM_x1 regs[1]
> +#define ARM_x0 regs[0]
> +#define ARM_ORIG_x0 orig_x0
> +
> /*
> * User structures for general purpose, floating point and debug registers.
> */
> diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
> index d882b83..adc1f39 100644
> --- a/arch/arm64/kernel/ptrace.c
> +++ b/arch/arm64/kernel/ptrace.c
> @@ -48,6 +48,122 @@
> #define CREATE_TRACE_POINTS
> #include <trace/events/syscalls.h>
>
> +struct pt_regs_offset {
> + const char *name;
> + int offset;
> +};
> +
> +#define REG_OFFSET_NAME(r) \
> + {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
> +#define REG_OFFSET_END {.name = NULL, .offset = 0}
> +
> +static const struct pt_regs_offset regoffset_table[] = {
> + REG_OFFSET_NAME(x0),
> + REG_OFFSET_NAME(x1),
> + REG_OFFSET_NAME(x2),
> + REG_OFFSET_NAME(x3),
> + REG_OFFSET_NAME(x4),
> + REG_OFFSET_NAME(x5),
> + REG_OFFSET_NAME(x6),
> + REG_OFFSET_NAME(x7),
> + REG_OFFSET_NAME(x8),
> + REG_OFFSET_NAME(x9),
> + REG_OFFSET_NAME(x10),
> + REG_OFFSET_NAME(x11),
> + REG_OFFSET_NAME(x12),
> + REG_OFFSET_NAME(x13),
> + REG_OFFSET_NAME(x14),
> + REG_OFFSET_NAME(x15),
> + REG_OFFSET_NAME(ip0),
> + REG_OFFSET_NAME(ip1),
> + REG_OFFSET_NAME(x18),
> + REG_OFFSET_NAME(x19),
> + REG_OFFSET_NAME(x20),
> + REG_OFFSET_NAME(x21),
> + REG_OFFSET_NAME(x22),
> + REG_OFFSET_NAME(x23),
> + REG_OFFSET_NAME(x24),
> + REG_OFFSET_NAME(x25),
> + REG_OFFSET_NAME(x26),
> + REG_OFFSET_NAME(x27),
> + REG_OFFSET_NAME(x28),
> + REG_OFFSET_NAME(fp),
> + REG_OFFSET_NAME(lr),
> + REG_OFFSET_NAME(sp),
> + REG_OFFSET_NAME(pc),
> + REG_OFFSET_NAME(cpsr),
> + REG_OFFSET_NAME(ORIG_x0),
> + REG_OFFSET_END,
> +};
> +
> +/**
> + * regs_query_register_offset() - query register offset from its name
> + * @name: the name of a register
> + *
> + * regs_query_register_offset() returns the offset of a register in struct
> + * pt_regs from its name. If the name is invalid, this returns -EINVAL;
> + */
> +int regs_query_register_offset(const char *name)
> +{
> + const struct pt_regs_offset *roff;
> +
> + for (roff = regoffset_table; roff->name != NULL; roff++)
> + if (!strcmp(roff->name, name))
> + return roff->offset;
> + return -EINVAL;
> +}
> +
> +/**
> + * regs_query_register_name() - query register name from its offset
> + * @offset: the offset of a register in struct pt_regs.
> + *
> + * regs_query_register_name() returns the name of a register from its
> + * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
> + */
> +const char *regs_query_register_name(unsigned int offset)
> +{
> + const struct pt_regs_offset *roff;
> +
> + for (roff = regoffset_table; roff->name != NULL; roff++)
> + if (roff->offset == offset)
> + return roff->name;
> + return NULL;
> +}
> +
> +/**
> + * regs_within_kernel_stack() - check the address in the stack
> + * @regs: pt_regs which contains kernel stack pointer.
> + * @addr: address which is checked.
> + *
> + * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
> + * If @addr is within the kernel stack, it returns true. If not, returns false.
> + */
> +bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
> +{
> + return ((addr & ~(THREAD_SIZE - 1)) ==
> + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
> +}
> +
> +/**
> + * regs_get_kernel_stack_nth() - get Nth entry of the stack
> + * @regs: pt_regs which contains kernel stack pointer.
> + * @n: stack entry number.
> + *
> + * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
> + * is specified by @regs. If the @n th entry is NOT in the kernel stack,
> + * this returns 0.
> + */
> +unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
> +{
> + unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
> +
> + addr += n;
> + if (regs_within_kernel_stack(regs, (unsigned long)addr))
> + return *addr;
> + else
> + return 0;
> +}
> +
> /*
> * TODO: does not yet catch signals sent when the child dies.
> * in exit.c or in signal.c.
>

--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx

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Next message: Pantelis Antoniou: "[PATCH 0/4] Device Tree Quirks & the Beaglebone"
Previous message: Aristeu Rozanski: "Re: [PATCH] n_tty_read: check for hanging tty while waiting for input"
In reply to: David Long: "[PATCH v5 1/6] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature"
Next in thread: David Long: "[PATCH v5 3/6] arm64: Kprobes with single stepping support"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]