On Fri, Nov 22, 2019 at 6:32 AM Paul Walmsley <paul.walmsley@xxxxxxxxxx> wrote: > > On Thu, 21 Nov 2019, Paul Walmsley wrote: > > > As I understand it, this patch hasn't been signed off on by Patrick. > > I've sent him an E-mail asking him whether he's willing to add his > > Signed-off-by:, but haven't heard back from it. > > > > From our discussions, I understand that this patch is based partially on > > some of his earlier, public, kprobes work. In lieu of any response from > > Patrick, could you please resend this patch and just note in the commit > > description that it's partially based on one of his patches, add a Link: > > line that points to the URL of the patch that it's partially based on, and > > replace the Signed-off-by: with a Co-developed-by: or something similar? > > OK - just looked at the patches more closely, and I think I see what's > going on here. This patch looks like a rebased version of this patch: > > https://lore.kernel.org/linux-riscv/20181113195804.22825-2-me@xxxxxxxx/ > > So let's just plan to use an updated version of Patrick's original > (below). Please let me know if you have any comments on it or if I > missed something - > > > - Paul > Dear Paul, Due to the rule of mail classification, I do not find this mail in time. I am sorry for that. I think it is good for me. Thanks and regards Vincent > From: Patrick Stählin <me@xxxxxxxx> > Date: Tue, 13 Nov 2018 20:58:03 +0100 > Subject: [PATCH] RISC-V: Implement ptrace regs and stack API > MIME-Version: 1.0 > Content-Type: text/plain; charset=UTF-8 > Content-Transfer-Encoding: 8bit > > Needed for kprobes support. Copied and adapted from arm64 code. > > Signed-off-by: Patrick Stählin <me@xxxxxxxx> > [paul.walmsley@xxxxxxxxxx: updated to apply; fixed checkpatch issues; > fixed regs_get_register() kerneldoc] > Cc: Vincent Chen <vincent.chen@xxxxxxxxxx> > Link: https://lore.kernel.org/linux-riscv/20181113195803.CjtBCsUcG9czwiqmPBGKUjvl5Ojxq2SIPaioQUHXFI0@z/ > Link: https://lore.kernel.org/linux-riscv/1572919114-3886-1-git-send-email-vincent.chen@xxxxxxxxxx/T/#mdb346527d25ea1959ab57ff9d1c056bcd29c7172 > Signed-off-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/include/asm/ptrace.h | 30 ++++++++++ > arch/riscv/kernel/ptrace.c | 99 +++++++++++++++++++++++++++++++++ > 3 files changed, 130 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 8eebbc8860bb..d5bbf4223fd2 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -61,6 +61,7 @@ config RISCV > select SPARSEMEM_STATIC if 32BIT > select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU > select HAVE_ARCH_MMAP_RND_BITS > + select HAVE_REGS_AND_STACK_ACCESS_API > > config ARCH_MMAP_RND_BITS_MIN > default 18 if 64BIT > diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h > index d48d1e13973c..50d37b123a61 100644 > --- a/arch/riscv/include/asm/ptrace.h > +++ b/arch/riscv/include/asm/ptrace.h > @@ -8,6 +8,7 @@ > > #include <uapi/asm/ptrace.h> > #include <asm/csr.h> > +#include <linux/compiler.h> > > #ifndef __ASSEMBLY__ > > @@ -60,6 +61,7 @@ struct pt_regs { > > #define user_mode(regs) (((regs)->sstatus & SR_SPP) == 0) > > +#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_a0) > > /* Helpers for working with the instruction pointer */ > static inline unsigned long instruction_pointer(struct pt_regs *regs) > @@ -85,6 +87,12 @@ static inline void user_stack_pointer_set(struct pt_regs *regs, > regs->sp = val; > } > > +/* Valid only for Kernel mode traps. */ > +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) > +{ > + return regs->sp; > +} > + > /* Helpers for working with the frame pointer */ > static inline unsigned long frame_pointer(struct pt_regs *regs) > { > @@ -101,6 +109,28 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) > return regs->a0; > } > > +int regs_query_register_offset(const char *name); > +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 from @regs of a register > + * identified by @offset. 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 unsigned long regs_get_register(struct pt_regs *regs, > + unsigned int offset) > +{ > + if (unlikely(offset > MAX_REG_OFFSET)) > + return 0; > + > + return *(unsigned long *)((unsigned long)regs + offset); > +} > #endif /* __ASSEMBLY__ */ > > #endif /* _ASM_RISCV_PTRACE_H */ > diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c > index 1252113ef8b2..5076b30fe18b 100644 > --- a/arch/riscv/kernel/ptrace.c > +++ b/arch/riscv/kernel/ptrace.c > @@ -125,6 +125,105 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) > return &riscv_user_native_view; > } > > +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} > + > +static const struct pt_regs_offset regoffset_table[] = { > + REG_OFFSET_NAME(sepc), > + REG_OFFSET_NAME(ra), > + REG_OFFSET_NAME(sp), > + REG_OFFSET_NAME(gp), > + REG_OFFSET_NAME(tp), > + REG_OFFSET_NAME(t0), > + REG_OFFSET_NAME(t1), > + REG_OFFSET_NAME(t2), > + REG_OFFSET_NAME(s0), > + REG_OFFSET_NAME(s1), > + REG_OFFSET_NAME(a0), > + REG_OFFSET_NAME(a1), > + REG_OFFSET_NAME(a2), > + REG_OFFSET_NAME(a3), > + REG_OFFSET_NAME(a4), > + REG_OFFSET_NAME(a5), > + REG_OFFSET_NAME(a6), > + REG_OFFSET_NAME(a7), > + REG_OFFSET_NAME(s2), > + REG_OFFSET_NAME(s3), > + REG_OFFSET_NAME(s4), > + REG_OFFSET_NAME(s5), > + REG_OFFSET_NAME(s6), > + REG_OFFSET_NAME(s7), > + REG_OFFSET_NAME(s8), > + REG_OFFSET_NAME(s9), > + REG_OFFSET_NAME(s10), > + REG_OFFSET_NAME(s11), > + REG_OFFSET_NAME(t3), > + REG_OFFSET_NAME(t4), > + REG_OFFSET_NAME(t5), > + REG_OFFSET_NAME(t6), > + REG_OFFSET_NAME(sstatus), > + REG_OFFSET_NAME(sbadaddr), > + REG_OFFSET_NAME(scause), > + REG_OFFSET_NAME(orig_a0), > + 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; roff++) > + if (!strcmp(roff->name, name)) > + return roff->offset; > + return -EINVAL; > +} > + > +/** > + * 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. > + */ > +static 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; > +} > + > void ptrace_disable(struct task_struct *child) > { > clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); > -- > 2.24.0.rc0
