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([94.75.70.14]) by smtp.gmail.com with ESMTPSA id q2-20020ac25a02000000b004fe07f06337sm753453lfn.53.2023.08.11.07.33.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Aug 2023 07:33:00 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: f9ca3bd4-3853-11ee-b284-6b7b168915f2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691764381; x=1692369181; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=WxemZPSrKphIU1DOnZWltN7srrgDFj6wafS5aBn4TaY=; b=RledqS7a4a44XsG7EKTMY24d/SDPhktwyck2xu6KGzJ7wyApw2dfUkQd7Kryd3TO1/ a5TgrjPSpWXNbIEhgiP1MnemhYvo/Lr102dhbYyr9A6jTFWPOHyuRdA584aSCTQeEO1S 1MQiQeqq0GFpRj/dpFRe7uVBzXr0aVrIQYwmpfMTu/quwxag+61u6TDRZXrmLEhLJ/4I n4hVXqoug9eVGd6w20vIrfK4eroSNCicM04l5OCxpWrUD+EamEGvlA0JrpZaTFHCcUc7 C9Kfnct8VHop8wCVc69ObTkBuNfHeafbAXIxFe6eFzyLKYAj3i5DaE399QspFyDppNnq qCfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691764381; x=1692369181; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=WxemZPSrKphIU1DOnZWltN7srrgDFj6wafS5aBn4TaY=; b=ft+g4b0aH+l074sNllTs/DVG/2admK8Pt3eGu3PhEIsAblkj/wP5AWaZwFs3TI7xX0 RMxMeelta3TfHaU01FiRlTp34ZuB6DSTdOL6EQqXjRhwlFUI8YrVjAOHR+Y/hdlE5bLF uuuHUz5XCFqifj1crin61aviR04x/xEDkN6jKyACQOsRIz4rhGF4v/9MMKFEcuu3/3U4 shE2+8MMUip7Sv2ySkxAny2UGKgLlD92djRXA7/uVHLx9U7oDwXl/xvAs10m9s6ApRTy GX3KhcqlfTE2d/tWieNlb/mxz6E7CWZs+WR07AS6hT9LSse33EoGDmMgFmVBX47+ccT3 m7wg== X-Gm-Message-State: AOJu0Yy4GMyHxyPDIVPOt+uBiv9qJ8A1Q8LQVysvunc9dN50Csy4YVX9 oVKCEDa9k1zB7Bk1QlIr/rTq98zotSw= X-Google-Smtp-Source: AGHT+IFdYvM9CDX0s6tuokZtE3ADXkxDijqkkbycTjKUe2GpoqCgYMO++xnf4wBPtEU2jr/fZOk7aA== X-Received: by 2002:a05:6512:3d8b:b0:4fd:d226:adcc with SMTP id k11-20020a0565123d8b00b004fdd226adccmr2129948lfv.21.1691764380992; Fri, 11 Aug 2023 07:33:00 -0700 (PDT) From: Oleksii Kurochko To: xen-devel@lists.xenproject.org Cc: Jan Beulich , Andrew Cooper , Oleksii Kurochko , Bob Eshleman , Alistair Francis , Connor Davis Subject: [PATCH v8 5/6] xen/riscv: implement do_bug_frame() Date: Fri, 11 Aug 2023 17:32:54 +0300 Message-ID: X-Mailer: git-send-email 2.41.0 In-Reply-To: References: MIME-Version: 1.0 The patch introduces the temporary implementation of do_bug_frame(). When common code is merged, CONFIG_GENERIC_BUG_FRAME should be used instead. Signed-off-by: Oleksii Kurochko --- Changes in V8: - remove Pointless initializer of id. - make bug_frames[] array constant. - remove cast_to_bug_frame(addr). - rename is_valig_bugaddr to is_valid_bug_insn(). - add check that read_instr is used only on xen code - update the commit message. --- Changes in V7: - move to this patch the definition of cast_to_bug_frame() from the previous patch. - update the comment in bug.h. - update the comment above do_bug_frame(). - fix code style. - add comment to read_instr func. - add space for bug_frames in lds.S. --- Changes in V6: - Avoid LINK_TO_LOAD() as bug.h functionality expected to be used after MMU is enabled. - Change early_printk() to printk() --- Changes in V5: - Remove "#include " from as there is no any need in it anymore - Update macros GET_INSN_LENGTH: remove UL and 'unsigned int len;' from it - Remove " include " from risc/setup.c. it is not needed in the current version of the patch - change an argument type from vaddr_t to uint32_t for is_valid_bugaddr and introduce read_instr() to read instruction properly as the length of qinstruction can be either 32 or 16 bits. - Code style fixes - update the comments before do_bug_frame() in riscv/trap.c - Refactor is_valid_bugaddr() function. - introduce macros cast_to_bug_frame(addr) to hide casts. - use LINK_TO_LOAD() for addresses which are linker time relative. --- Changes in V4: - Updates in RISC-V's : * Add explanatory comment about why there is only defined for 32-bits length instructions and 16/32-bits BUG_INSN_{16,32}. * Change 'unsigned long' to 'unsigned int' inside GET_INSN_LENGTH(). * Update declaration of is_valid_bugaddr(): switch return type from int to bool and the argument from 'unsigned int' to 'vaddr'. - Updates in RISC-V's traps.c: * replace /xen and /asm includes * update definition of is_valid_bugaddr():switch return type from int to bool and the argument from 'unsigned int' to 'vaddr'. Code style inside function was updated too. * do_bug_frame() refactoring: * local variables start and bug became 'const struct bug_frame' * bug_frames[] array became 'static const struct bug_frame[] = ...' * remove all casts * remove unneeded comments and add an explanatory comment that the do_bug_frame() will be switched to a generic one. * do_trap() refactoring: * read 16-bits value instead of 32-bits as compressed instruction can be used and it might happen than only 16-bits may be accessible. * code style updates * re-use instr variable instead of re-reading instruction. - Updates in setup.c: * add blank line between xen/ and asm/ includes. --- Changes in V3: - Rebase the patch "xen/riscv: introduce an implementation of macros from " on top of patch series [introduce generic implementation of macros from bug.h] --- Changes in V2: - Remove __ in define namings - Update run_in_exception_handler() with register void *fn_ asm(__stringify(BUG_FN_REG)) = (fn); - Remove bug_instr_t type and change it's usage to uint32_t --- xen/arch/riscv/traps.c | 138 +++++++++++++++++++++++++++++++++++++++ xen/arch/riscv/xen.lds.S | 10 +++ 2 files changed, 148 insertions(+) diff --git a/xen/arch/riscv/traps.c b/xen/arch/riscv/traps.c index c1175668b6..b096dce6c7 100644 --- a/xen/arch/riscv/traps.c +++ b/xen/arch/riscv/traps.c @@ -5,6 +5,8 @@ * RISC-V Trap handlers */ +#include +#include #include #include @@ -101,7 +103,143 @@ static void do_unexpected_trap(const struct cpu_user_regs *regs) die(); } +void show_execution_state(const struct cpu_user_regs *regs) +{ + printk("implement show_execution_state(regs)\n"); +} + +/* + * TODO: generic do_bug_frame() should be used instead of current + * implementation panic(), printk() and find_text_region() + * (virtual memory?) will be ready/merged + */ +int do_bug_frame(const struct cpu_user_regs *regs, vaddr_t pc) +{ + const struct bug_frame *start, *end; + const struct bug_frame *bug = NULL; + unsigned int id; + const char *filename, *predicate; + int lineno; + + static const struct bug_frame * const bug_frames[] = { + &__start_bug_frames[0], + &__stop_bug_frames_0[0], + &__stop_bug_frames_1[0], + &__stop_bug_frames_2[0], + &__stop_bug_frames_3[0], + }; + + for ( id = 0; id < BUGFRAME_NR; id++ ) + { + start = bug_frames[id]; + end = bug_frames[id + 1]; + + while ( start != end ) + { + if ( (vaddr_t)bug_loc(start) == pc ) + { + bug = start; + goto found; + } + + start++; + } + } + + found: + if ( bug == NULL ) + return -ENOENT; + + if ( id == BUGFRAME_run_fn ) + { + void (*fn)(const struct cpu_user_regs *) = bug_ptr(bug); + + fn(regs); + + goto end; + } + + /* WARN, BUG or ASSERT: decode the filename pointer and line number. */ + filename = bug_ptr(bug); + lineno = bug_line(bug); + + switch ( id ) + { + case BUGFRAME_warn: + printk("Xen WARN at %s:%d\n", filename, lineno); + + show_execution_state(regs); + + goto end; + + case BUGFRAME_bug: + printk("Xen BUG at %s:%d\n", filename, lineno); + + show_execution_state(regs); + + printk("change wait_for_interrupt to panic() when common is available\n"); + die(); + + case BUGFRAME_assert: + /* ASSERT: decode the predicate string pointer. */ + predicate = bug_msg(bug); + + printk("Assertion %s failed at %s:%d\n", predicate, filename, lineno); + + show_execution_state(regs); + + printk("change wait_for_interrupt to panic() when common is available\n"); + die(); + } + + return -EINVAL; + + end: + return 0; +} + +static bool is_valid_bug_insn(uint32_t insn) +{ + return insn == BUG_INSN_32 || + (insn & COMPRESSED_INSN_MASK) == BUG_INSN_16; +} + +/* There are no guests for now so the func has to return alwasys false */ +static inline bool guest_mode(void) +{ + return false; +} + +/* Should be used only on Xen code */ +static uint32_t read_instr(unsigned long pc) +{ + uint16_t instr16 = *(uint16_t *)pc; + + if ( guest_mode() ) + { + printk("%s should be called only on Xen code\n", __func__); + die(); + } + + if ( GET_INSN_LENGTH(instr16) == 2 ) + return instr16; + else + return *(uint32_t *)pc; +} + void do_trap(struct cpu_user_regs *cpu_regs) { + register_t pc = cpu_regs->sepc; + uint32_t instr = read_instr(pc); + + if ( is_valid_bug_insn(instr) ) + { + if ( !do_bug_frame(cpu_regs, pc) ) + { + cpu_regs->sepc += GET_INSN_LENGTH(instr); + return; + } + } + do_unexpected_trap(cpu_regs); } diff --git a/xen/arch/riscv/xen.lds.S b/xen/arch/riscv/xen.lds.S index 3fa7db3bf9..a10e0ad87c 100644 --- a/xen/arch/riscv/xen.lds.S +++ b/xen/arch/riscv/xen.lds.S @@ -45,6 +45,16 @@ SECTIONS . = ALIGN(PAGE_SIZE); .rodata : { _srodata = .; /* Read-only data */ + /* Bug frames table */ + __start_bug_frames = .; + *(.bug_frames.0) + __stop_bug_frames_0 = .; + *(.bug_frames.1) + __stop_bug_frames_1 = .; + *(.bug_frames.2) + __stop_bug_frames_2 = .; + *(.bug_frames.3) + __stop_bug_frames_3 = .; *(.rodata) *(.rodata.*) *(.data.rel.ro)