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keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <1eb9050ff6632f91682151471440990bd718ed90.1784560663.git.oleksii.kurochko@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-purgate-ID: tlsNG-42698a/1786545447-A88C99EA-53675707/0/0 X-purgate-type: clean X-purgate-size: 4227 On 20.07.2026 18:02, Oleksii Kurochko wrote: > @@ -60,6 +68,40 @@ static void ex_handler_fixup(const struct exception_table_entry *ex, > regs->sepc = ex_fixup(ex); > } > > +static inline unsigned long regs_get_gpr(struct cpu_user_regs *regs, > + unsigned int offset) > +{ > + /* > + * The GPR number -> offset arithmetic below relies on x0..x31 being > + * laid out at the start of struct cpu_user_regs in architectural > + * order. > + */ > + BUILD_BUG_ON(offsetof(struct cpu_user_regs, ra) != > + sizeof(unsigned long)); > + BUILD_BUG_ON(offsetof(struct cpu_user_regs, t6) != > + 31 * sizeof(unsigned long)); > + > + if ( unlikely(!offset || (offset > MAX_REG_OFFSET)) ) > + return 0; And an offset not divisible by sizeof(unsigned long) is okay? Returning 0 as error indicator also feels fragile. > + return *(unsigned long *)((unsigned long)regs + offset); > +} > + > +static void ex_handler_trap_info(const struct exception_table_entry *ex, > + struct cpu_user_regs *regs) > +{ > + struct trap_info *trap_info = > + (struct trap_info *)regs_get_gpr(regs, ex->data * sizeof(unsigned long)); Related to the earlier comment: Simply pass just ex->data here, leaving the multiplication to regs_get_gpr()? > + BUG_ON(!trap_info); > + > + trap_info->sepc = csr_read(CSR_SEPC); > + trap_info->scause = csr_read(CSR_SCAUSE); > + trap_info->stval = csr_read(CSR_STVAL); Do you really need to re-read all three registers here? Didn't you read at least scause already, in order to make it here in the first place? > --- a/xen/arch/riscv/include/asm/extable.h > +++ b/xen/arch/riscv/include/asm/extable.h > @@ -3,17 +3,24 @@ > #ifndef ASM__RISCV__ASM_EXTABLE_H > #define ASM__RISCV__ASM_EXTABLE_H > > +#include > + > +#define EX_TYPE_FIXUP 0 > +#define EX_TYPE_TRAP_INFO 1 > + > #ifdef __ASSEMBLER__ > > -#define ASM_EXTABLE(insn, fixup) \ > - .pushsection .ex_table, "a"; \ > - .balign 4; \ > - .word (insn) - .; \ > - .word (fixup) - .; \ > - .popsection > +#define ASM_EXTABLE_RAW(insn, fixup, type, data) \ > + .pushsection .ex_table, "a"; \ > + .balign 4; \ > + .long ((insn) - .); \ > + .long ((fixup) - .); \ Why the change from .word to .long? And why the extra pairs of parens? > + .short (type); \ > + .short (data); \ Alongside .word, these then likely want to be .half. > @@ -23,20 +30,36 @@ > > struct cpu_user_regs; > > -#define ASM_EXTABLE(insn, fixup) \ > - ".pushsection .ex_table, \"a\"\n" \ > - ".balign 4\n" \ > - ".word (" #insn " - .)\n" \ > - ".word (" #fixup " - .)\n" \ > +#define ASM_EXTABLE_RAW(insn, fixup, type, data) \ > + ".pushsection .ex_table, \"a\"\n" \ > + ".balign 4\n" \ > + ".long ((" insn ") - .)\n" \ > + ".long ((" fixup ") - .)\n" \ Same questions here then. > --- /dev/null > +++ b/xen/arch/riscv/include/asm/gpr-num.h > @@ -0,0 +1,33 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +#ifndef RISCV_GPR_NUM_H > +#define RISCV_GPR_NUM_H > + > +/* GPR ABI names, in register-number order (x0 .. x31). */ > +#define GPR_ABI_NAMES \ > + zero, ra, sp, gp, tp, t0, t1, t2, \ > + s0, s1, a0, a1, a2, a3, a4, a5, \ > + a6, a7, s2, s3, s4, s5, s6, s7, \ > + s8, s9, s10, s11, t3, t4, t5, t6 > + > +#ifdef __ASSEMBLER__ > + > + .equ .L_gpr_num, 0 > + .irp name, GPR_ABI_NAMES > + .equ .L_gpr_num_\name, .L_gpr_num > + .equ .L_gpr_num, .L_gpr_num + 1 > + .endr So this is emitted no matter whether a .S file actually uses any of the constants. Perhaps okayish, but somewhat wasteful. Jan