Messages in this thread | | | Subject | Re: [PATCH v13 01/10] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature | From | Li Bin <> | Date | Mon, 20 Jun 2016 10:43:12 +0800 |
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on 2016/6/3 11:26, David Long wrote: > From: "David A. Long" <dave.long@linaro.org> > > Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64, including supporting > functions and defines. > > Signed-off-by: David A. Long <dave.long@linaro.org> > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/ptrace.h | 54 +++++++++++++++++- > arch/arm64/kernel/ptrace.c | 118 ++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 172 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 76747d9..0f7a624 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -85,6 +85,7 @@ 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 IOMMU_DMA if IOMMU_SUPPORT > diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h > index a307eb6..c130f2b 100644 > --- a/arch/arm64/include/asm/ptrace.h > +++ b/arch/arm64/include/asm/ptrace.h > @@ -74,6 +74,7 @@ > #define COMPAT_PT_DATA_ADDR 0x10004 > #define COMPAT_PT_TEXT_END_ADDR 0x10008 > #ifndef __ASSEMBLY__ > +#include <linux/bug.h> > > /* sizeof(struct user) for AArch32 */ > #define COMPAT_USER_SZ 296 > @@ -119,6 +120,8 @@ struct pt_regs { > u64 syscallno; > }; > > +#define MAX_REG_OFFSET offsetof(struct pt_regs, pstate) > + > #define arch_has_single_step() (1) > > #ifdef CONFIG_COMPAT > @@ -147,6 +150,55 @@ struct pt_regs { > #define user_stack_pointer(regs) \ > (!compat_user_mode(regs) ? (regs)->sp : (regs)->compat_sp) > > +extern int regs_query_register_offset(const char *name); > +extern const char *regs_query_register_name(unsigned int offset); > +extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr); > +extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, > + unsigned int n); > + > +/** > + * regs_get_register() - get register value from its offset > + * @regs: pt_regs from which register value is gotten > + * @offset: offset 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) > +{ > + u64 val = 0; > + > + WARN_ON(offset & 7); > + > + offset >>= 3;
Here, the offset is 3-bits right shifted. So,
> + switch (offset) { > + case 0 ... 30: > + val = regs->regs[offset]; > + break; > + case offsetof(struct pt_regs, sp):
here should be shifted too, as
case offsetof(struct pt_regs, sp) >> 3:
> + val = regs->sp; > + break; > + case offsetof(struct pt_regs, pc):
and here,
> + val = regs->pc; > + break; > + case offsetof(struct pt_regs, pstate):
and here.
thanks, Li Bin
> + val = regs->pstate; > + break; > + default: > + val = 0; > + } > + > + return val; > +} > + > +/* Valid only for Kernel mode traps. */ > +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) > +{ > + return regs->sp; > +} > + > static inline unsigned long regs_return_value(struct pt_regs *regs) > { > return regs->regs[0]; > @@ -156,7 +208,7 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) > struct task_struct; > int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task); > > -#define instruction_pointer(regs) ((unsigned long)(regs)->pc) > +#define instruction_pointer(regs) ((regs)->pc) > > extern unsigned long profile_pc(struct pt_regs *regs); > > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index 3f6cd5c..2c88c33 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -48,6 +48,124 @@ > #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, r)} > +#define REG_OFFSET_END {.name = NULL, .offset = 0} > +#define GPR_OFFSET_NAME(r) \ > + {.name = "x" #r, .offset = offsetof(struct pt_regs, regs[r])} > + > +static const struct pt_regs_offset regoffset_table[] = { > + GPR_OFFSET_NAME(0), > + GPR_OFFSET_NAME(1), > + GPR_OFFSET_NAME(2), > + GPR_OFFSET_NAME(3), > + GPR_OFFSET_NAME(4), > + GPR_OFFSET_NAME(5), > + GPR_OFFSET_NAME(6), > + GPR_OFFSET_NAME(7), > + GPR_OFFSET_NAME(8), > + GPR_OFFSET_NAME(9), > + GPR_OFFSET_NAME(10), > + GPR_OFFSET_NAME(11), > + GPR_OFFSET_NAME(12), > + GPR_OFFSET_NAME(13), > + GPR_OFFSET_NAME(14), > + GPR_OFFSET_NAME(15), > + GPR_OFFSET_NAME(16), > + GPR_OFFSET_NAME(17), > + GPR_OFFSET_NAME(18), > + GPR_OFFSET_NAME(19), > + GPR_OFFSET_NAME(20), > + GPR_OFFSET_NAME(21), > + GPR_OFFSET_NAME(22), > + GPR_OFFSET_NAME(23), > + GPR_OFFSET_NAME(24), > + GPR_OFFSET_NAME(25), > + GPR_OFFSET_NAME(26), > + GPR_OFFSET_NAME(27), > + GPR_OFFSET_NAME(28), > + GPR_OFFSET_NAME(29), > + GPR_OFFSET_NAME(30), > + {.name = "lr", .offset = offsetof(struct pt_regs, regs[30])}, > + REG_OFFSET_NAME(sp), > + REG_OFFSET_NAME(pc), > + REG_OFFSET_NAME(pstate), > + 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))) || > + on_irq_stack(addr, raw_smp_processor_id()); > +} > + > +/** > + * 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. >
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