| Message ID | 20230327164941.20491-12-andy.chiu@sifive.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: Add vector ISA support | expand |
On Montag, 27. März 2023 18:49:31 CEST Andy Chiu wrote: > From: Greentime Hu <greentime.hu@sifive.com> > > This patch adds ptrace support for riscv vector. The vector registers will > be saved in datap pointer of __riscv_v_ext_state. This pointer will be set > right after the __riscv_v_ext_state data structure then it will be put in > ubuf for ptrace system call to get or set. It will check if the datap got > from ubuf is set to the correct address or not when the ptrace system call > is trying to set the vector registers. > > Co-developed-by: Vincent Chen <vincent.chen@sifive.com> > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > Signed-off-by: Greentime Hu <greentime.hu@sifive.com> > Signed-off-by: Andy Chiu <andy.chiu@sifive.com> > Reviewed-by: Conor Dooley <conor.dooley@microchip.com> > --- > arch/riscv/include/uapi/asm/ptrace.h | 7 +++ > arch/riscv/kernel/ptrace.c | 70 ++++++++++++++++++++++++++++ > include/uapi/linux/elf.h | 1 + > 3 files changed, 78 insertions(+) > > diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c > index 23c48b14a0e7..75e66c040b64 100644 > --- a/arch/riscv/kernel/ptrace.c > +++ b/arch/riscv/kernel/ptrace.c > @@ -80,6 +84,61 @@ static int riscv_fpr_set(struct task_struct *target, > } > #endif > > +#ifdef CONFIG_RISCV_ISA_V > +static int riscv_vr_get(struct task_struct *target, > + const struct user_regset *regset, > + struct membuf to) > +{ > + struct __riscv_v_ext_state *vstate = &target->thread.vstate; > + > + if (!riscv_v_vstate_query(task_pt_regs(target))) > + return -EINVAL; > + > + /* > + * Ensure the vector registers have been saved to the memory before > + * copying them to membuf. > + */ > + if (target == current) > + riscv_v_vstate_save(current, task_pt_regs(current)); > + > + /* Copy vector header from vstate. */ > + membuf_write(&to, vstate, offsetof(struct __riscv_v_ext_state, datap)); > + membuf_zero(&to, sizeof(void *)); No idea why I have not seen it in any previous version, but this "sizeof(void *)" just made me thing "what is going on here?". I personally would have written something like "sizeof(to.var)" or "offsetof(to.buf)" or something like that. That makes it easier for me to understand what is skipped/zeroed here, let alone making it a bit more fool proof when someone changes one of the struct layouts. YMMV. Regards, Eike
On Tue, Mar 28, 2023 at 1:53 PM Rolf Eike Beer <eb@emlix.com> wrote: > > On Montag, 27. März 2023 18:49:31 CEST Andy Chiu wrote: > > From: Greentime Hu <greentime.hu@sifive.com> > > > > This patch adds ptrace support for riscv vector. The vector registers will > > be saved in datap pointer of __riscv_v_ext_state. This pointer will be set > > right after the __riscv_v_ext_state data structure then it will be put in > > ubuf for ptrace system call to get or set. It will check if the datap got > > from ubuf is set to the correct address or not when the ptrace system call > > is trying to set the vector registers. > > > > Co-developed-by: Vincent Chen <vincent.chen@sifive.com> > > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > > Signed-off-by: Greentime Hu <greentime.hu@sifive.com> > > Signed-off-by: Andy Chiu <andy.chiu@sifive.com> > > Reviewed-by: Conor Dooley <conor.dooley@microchip.com> > > --- > > arch/riscv/include/uapi/asm/ptrace.h | 7 +++ > > arch/riscv/kernel/ptrace.c | 70 ++++++++++++++++++++++++++++ > > include/uapi/linux/elf.h | 1 + > > 3 files changed, 78 insertions(+) > > > > diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c > > index 23c48b14a0e7..75e66c040b64 100644 > > --- a/arch/riscv/kernel/ptrace.c > > +++ b/arch/riscv/kernel/ptrace.c > > @@ -80,6 +84,61 @@ static int riscv_fpr_set(struct task_struct *target, > > } > > #endif > > > > +#ifdef CONFIG_RISCV_ISA_V > > +static int riscv_vr_get(struct task_struct *target, > > + const struct user_regset *regset, > > + struct membuf to) > > +{ > > + struct __riscv_v_ext_state *vstate = &target->thread.vstate; > > + > > + if (!riscv_v_vstate_query(task_pt_regs(target))) > > + return -EINVAL; > > + > > + /* > > + * Ensure the vector registers have been saved to the memory before > > + * copying them to membuf. > > + */ > > + if (target == current) > > + riscv_v_vstate_save(current, task_pt_regs(current)); > > + > > + /* Copy vector header from vstate. */ > > + membuf_write(&to, vstate, offsetof(struct __riscv_v_ext_state, > datap)); > > + membuf_zero(&to, sizeof(void *)); > > No idea why I have not seen it in any previous version, but this "sizeof(void > *)" just made me thing "what is going on here?". I personally would have > written something like "sizeof(to.var)" or "offsetof(to.buf)" or something like > that. That makes it easier for me to understand what is skipped/zeroed here, > let alone making it a bit more fool proof when someone changes one of the > struct layouts. YMMV. > Thanks for the finding. Fixing it now > Regards, > > Eike > -- > Rolf Eike Beer, emlix GmbH, http://www.emlix.com > Fon +49 551 30664-0, Fax +49 551 30664-11 > Gothaer Platz 3, 37083 Göttingen, Germany > Sitz der Gesellschaft: Göttingen, Amtsgericht Göttingen HR B 3160 > Geschäftsführung: Heike Jordan, Dr. Uwe Kracke – Ust-IdNr.: DE 205 198 055 > > emlix - smart embedded open source Cheers, Andy
diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h index 586786d023c4..e8d127ec5cf7 100644 --- a/arch/riscv/include/uapi/asm/ptrace.h +++ b/arch/riscv/include/uapi/asm/ptrace.h @@ -94,6 +94,13 @@ struct __riscv_v_ext_state { */ }; +/* + * According to spec: The number of bits in a single vector register, + * VLEN >= ELEN, which must be a power of 2, and must be no greater than + * 2^16 = 65536bits = 8192bytes + */ +#define RISCV_MAX_VLENB (8192) + #endif /* __ASSEMBLY__ */ #endif /* _UAPI_ASM_RISCV_PTRACE_H */ diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c index 23c48b14a0e7..75e66c040b64 100644 --- a/arch/riscv/kernel/ptrace.c +++ b/arch/riscv/kernel/ptrace.c @@ -7,6 +7,7 @@ * Copied from arch/tile/kernel/ptrace.c */ +#include <asm/vector.h> #include <asm/ptrace.h> #include <asm/syscall.h> #include <asm/thread_info.h> @@ -24,6 +25,9 @@ enum riscv_regset { #ifdef CONFIG_FPU REGSET_F, #endif +#ifdef CONFIG_RISCV_ISA_V + REGSET_V, +#endif }; static int riscv_gpr_get(struct task_struct *target, @@ -80,6 +84,61 @@ static int riscv_fpr_set(struct task_struct *target, } #endif +#ifdef CONFIG_RISCV_ISA_V +static int riscv_vr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct __riscv_v_ext_state *vstate = &target->thread.vstate; + + if (!riscv_v_vstate_query(task_pt_regs(target))) + return -EINVAL; + + /* + * Ensure the vector registers have been saved to the memory before + * copying them to membuf. + */ + if (target == current) + riscv_v_vstate_save(current, task_pt_regs(current)); + + /* Copy vector header from vstate. */ + membuf_write(&to, vstate, offsetof(struct __riscv_v_ext_state, datap)); + membuf_zero(&to, sizeof(void *)); + + /* Copy all the vector registers from vstate. */ + return membuf_write(&to, vstate->datap, riscv_v_vsize); +} + +static int riscv_vr_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret, size; + struct __riscv_v_ext_state *vstate = &target->thread.vstate; + + if (!riscv_v_vstate_query(task_pt_regs(target))) + return -EINVAL; + + /* Copy rest of the vstate except datap */ + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate, 0, + offsetof(struct __riscv_v_ext_state, datap)); + if (unlikely(ret)) + return ret; + + /* Skip copy datap. */ + size = sizeof(vstate->datap); + count -= size; + ubuf += size; + + /* Copy all the vector registers. */ + pos = 0; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate->datap, + 0, riscv_v_vsize); + return ret; +} +#endif + static const struct user_regset riscv_user_regset[] = { [REGSET_X] = { .core_note_type = NT_PRSTATUS, @@ -99,6 +158,17 @@ static const struct user_regset riscv_user_regset[] = { .set = riscv_fpr_set, }, #endif +#ifdef CONFIG_RISCV_ISA_V + [REGSET_V] = { + .core_note_type = NT_RISCV_VECTOR, + .align = 16, + .n = ((32 * RISCV_MAX_VLENB) + + sizeof(struct __riscv_v_ext_state)) / sizeof(__u32), + .size = sizeof(__u32), + .regset_get = riscv_vr_get, + .set = riscv_vr_set, + }, +#endif }; static const struct user_regset_view riscv_user_native_view = { diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index ac3da855fb19..7d8d9ae36615 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -440,6 +440,7 @@ typedef struct elf64_shdr { #define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */ #define NT_MIPS_FP_MODE 0x801 /* MIPS floating-point mode */ #define NT_MIPS_MSA 0x802 /* MIPS SIMD registers */ +#define NT_RISCV_VECTOR 0x900 /* RISC-V vector registers */ #define NT_LOONGARCH_CPUCFG 0xa00 /* LoongArch CPU config registers */ #define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status registers */ #define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension registers */