| Message ID | 1429561187-3661-2-git-send-email-dave.long@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
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On Mon, Apr 20, 2015 at 04:19:42PM -0400, David Long wrote: > diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h > index 6913643..58c0223 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_pstate 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 I replied some time ago on this part. I don't see the point these macros. > + > /* > * 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..a889f79 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)} Can you not just use "offsetof(struct pt_regs, r)" here? That would be the same as x86, powerpc. > +#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), and stick to x16, x17, x29, x30 instead of the ip0 etc. > + REG_OFFSET_NAME(pstate), > + REG_OFFSET_NAME(ORIG_x0), > + REG_OFFSET_END, Do we need orig_x0 of MAX_REG_OFFSET doesn't include it? > +}; > + > +/** > + * 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; > +} BTW, these functions together with the pt_regs_offset structure look the same on the other architectures. Can we move them to some common header to avoid duplication (e.g. linux/ptrace.h)? > + > +/** > + * 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; > +} Same here.
On 05/20/15 09:39, Catalin Marinas wrote: > On Mon, Apr 20, 2015 at 04:19:42PM -0400, David Long wrote: >> diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h >> index 6913643..58c0223 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_pstate 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 > > I replied some time ago on this part. I don't see the point these > macros. > I replied belatedly on April 20 saying what I did matches (more or less) how it's done on various other platforms, including arm and powerpc. It looks like this comes from the pt_regs structure defining the registers as an array instead of a list of structure fields. It looks to me like that design choice is pretty widely depended upon now and would be quite disruptive to change. It also seems to me a relatively clean way to do it on systems with a uniform register set. >> + >> /* >> * 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..a889f79 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)} > > Can you not just use "offsetof(struct pt_regs, r)" here? That would be > the same as x86, powerpc. > The registers (except for pc, pstate, and sp) are not separate structure fields, they are slots in a single array. To reference them the symbolic name has to be converted to an index (integer register number) somehow. >> +#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), > > and stick to x16, x17, x29, x30 instead of the ip0 etc. > OK. >> + REG_OFFSET_NAME(pstate), >> + REG_OFFSET_NAME(ORIG_x0), >> + REG_OFFSET_END, > > Do we need orig_x0 of MAX_REG_OFFSET doesn't include it? > I think this should indeed be removed. >> +}; >> + >> +/** >> + * 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; >> +} > > BTW, these functions together with the pt_regs_offset structure look the > same on the other architectures. Can we move them to some common header > to avoid duplication (e.g. linux/ptrace.h)? > Common header *and* .c files? Yes, I see your point. >> + >> +/** >> + * 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; >> +} > > Same here. > Also makes sense and looks doable. -dl
On Wed, May 20, 2015 at 11:29:24PM -0400, David Long wrote: > On 05/20/15 09:39, Catalin Marinas wrote: > >On Mon, Apr 20, 2015 at 04:19:42PM -0400, David Long wrote: > >>diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h > >>index 6913643..58c0223 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_pstate 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 > > > >I replied some time ago on this part. I don't see the point these > >macros. > > I replied belatedly on April 20 saying what I did matches (more or less) how > it's done on various other platforms, including arm and powerpc. > It looks like this comes from the pt_regs structure defining the > registers as an array instead of a list of structure fields. It looks > to me like that design choice is pretty widely depended upon now and > would be quite disruptive to change. It also seems to me a relatively > clean way to do it on systems with a uniform register set. I see why we need to cope with the regs[] array but why do we need these definitions in a uapi file? > >>+ > >> /* > >> * 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..a889f79 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)} > > >Can you not just use "offsetof(struct pt_regs, r)" here? That would be > >the same as x86, powerpc. > > The registers (except for pc, pstate, and sp) are not separate structure > fields, they are slots in a single array. To reference them the symbolic > name has to be converted to an index (integer register number) somehow. Can we not keep them local to this file, say __reg_x0 etc. (something to make it clear they are for internal use)?
On 05/21/15 13:55, Catalin Marinas wrote: > On Wed, May 20, 2015 at 11:29:24PM -0400, David Long wrote: >> On 05/20/15 09:39, Catalin Marinas wrote: >>> On Mon, Apr 20, 2015 at 04:19:42PM -0400, David Long wrote: >>>> diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h >>>> index 6913643..58c0223 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_pstate 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 >>> >>> I replied some time ago on this part. I don't see the point these >>> macros. >> >> I replied belatedly on April 20 saying what I did matches (more or less) how >> it's done on various other platforms, including arm and powerpc. >> It looks like this comes from the pt_regs structure defining the >> registers as an array instead of a list of structure fields. It looks >> to me like that design choice is pretty widely depended upon now and >> would be quite disruptive to change. It also seems to me a relatively >> clean way to do it on systems with a uniform register set. > > I see why we need to cope with the regs[] array but why do we need these > definitions in a uapi file? > I expect Sandeepa did it that way because it's the way it's done in other architectures. I see your point though, these definitions are only referenced in a macro that's defined and used only in ptrace.c. I can easily move them there. >>>> + >>>> /* >>>> * 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..a889f79 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)} >> >>> Can you not just use "offsetof(struct pt_regs, r)" here? That would be >>> the same as x86, powerpc. >> >> The registers (except for pc, pstate, and sp) are not separate structure >> fields, they are slots in a single array. To reference them the symbolic >> name has to be converted to an index (integer register number) somehow. > > Can we not keep them local to this file, say __reg_x0 etc. (something to > make it clear they are for internal use)? > As above we can make it local to the file. Given that I don't think there's a need to chance ARM_x* to __reg_x* though, is there? Either way, no problem. -dl
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1b8e973..987a681 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -65,6 +65,7 @@ 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 d6dd9fd..655620e 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -118,6 +118,8 @@ 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 @@ -146,11 +148,38 @@ 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..58c0223 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_pstate 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..a889f79 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(pstate), + 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.