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([94.75.70.14]) by smtp.gmail.com with ESMTPSA id 38308e7fff4ca-2ef26f1bc4asm14240491fa.40.2024.07.24.08.31.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jul 2024 08:31:24 -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: c9b6fadd-49d1-11ef-8776-851b0ebba9a2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721835085; x=1722439885; darn=lists.xenproject.org; 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=bpktRcDF4JrvwzNydeWsiF50yQbYjN8viWEOOJ/BjaU=; b=hGRw7yGdLUCk6LwVIMhK6Gfi+FUyO4VVBomGkhwNa3bv8IpBRatDtKsAHyXTTbmJBA f0OjEDWfpAugXSNYyEfzzgZFrvVCmYHF+jlCoEpgGlg1MfZ3ebPvLZX6DEEoow4KjBGd 5czRDPo4L/4ajAdmD68EnmrcL6E/ovEBpMAlJGvlng1meIVn/0NZXXPhKyBOdkPI2VAM e6/B3jVAsW2B3D7gzNT1rkTsj9WZkczS3JjbbM5lm2a3b4RRxxk8L9/Iv+LazsihmDKb oDkaTvTxeySdx0Sjlell2fDwi9YekKFU8tbMI55WevAY5lfRQFt2z9HWRqydUGB+VDjT qChg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721835085; x=1722439885; 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=bpktRcDF4JrvwzNydeWsiF50yQbYjN8viWEOOJ/BjaU=; b=ANlELxkhBhzOYnJkIBNsYswwtkoGixV2dE8JUB2w1+ZBuBg1ugM04bW3/O3CFbb4Mq 86nsWr61F+yskP5jtou0Pb5PZzvqZ0/xdVpXn5kKwiPhe4OiTr6DQZxWrA3PZJSWxGGN TZ5qoP7Phlyo+HVQrTVsAOX4/PCPM3GrP/+ITzvF6o/Loi67+D/YgznAZCko8GGuDkyq S8Xxw76j829nCJmkXp1aGwZlPxit4zlyYPYmocRhtDX6Fn7YDcIELk2P9PHjXXABhyD1 jhY9DMtNMBxNNAw47kSdKwtihTdQshr/8LD/TAnCeMIujhEM4rWzEFMneTzNaqLtrtEk G4iQ== X-Gm-Message-State: AOJu0YyWaQbw+l4Gn4vEsmKtVo0Q4Di9pwpQBQuZn0RUtEY4eS7RgygQ 449FOGd1m8/EQqNPlNhJsCauclQfiOL/dPm3JAJ5PXMeUqw/YSydIc0NtzWx X-Google-Smtp-Source: AGHT+IELHpp33w+d2EYJm05wyLCODNBCJpRwvJRY8k7ZAX0tgnXUa47x7DGhJXJpLl7gMEbK/r92dw== X-Received: by 2002:a2e:a543:0:b0:2ef:18b7:440a with SMTP id 38308e7fff4ca-2f039cdb6b2mr2098601fa.22.1721835084463; Wed, 24 Jul 2024 08:31:24 -0700 (PDT) From: Oleksii Kurochko To: xen-devel@lists.xenproject.org Cc: Oleksii Kurochko Subject: [PATCH v11 4/5] xen/riscv: enable GENERIC_BUG_FRAME Date: Wed, 24 Jul 2024 17:31:18 +0200 Message-ID: X-Mailer: git-send-email 2.45.2 In-Reply-To: References: MIME-Version: 1.0 To have working BUG(), WARN(), ASSERT, run_in_exception_handler() it is needed to enable GENERIC_BUG_FRAME. ebreak is used as BUG_insn so when macros from are used, an exception with BREAKPOINT cause will be generated. ebreak triggers a debug trap, which starts in debug mode and is then filtered by every mode. A debugger will first handle the debug trap and check if ebreak was set by it or not. If not, CAUSE_BREAKPOINT will be generated for the mode where the ebreak instruction was executed. Also, is needed to be included for the reason that panic() and printk() are used in common/bug.c and RISC-V fails if it is not included. Signed-off-by: Oleksii Kurochko --- Changes in V11: - update the commit message - change "%lx" to "%#x" for PC register printing. - drop +1 in argument of is_kernel_text(pc) and is_kernel_inittext(pc). - drop return for case CAUSE_BREAKPOINT. - add break to default and add a blank like above it. - add a comment CAUSE_BREAKPOINT is handled instead of illegal instruction. --- Changes in V10: - put 'select GENERIC_BUG_FRAME' in "Config RISCV". - rework do_trap() to not fetch an instruction in case when the cause of trap is BUG_insn. - drop read_instr() and is_valid_bug_insn(). - update the commit message. --- Changes in V9: - Rebase on the top of current staging. - use GENERIC_BUG_FRAME as now we have common code available. - add xen/lib.h to bug.c to fix a compilation error around printk. - update the commit message. - update the code of read_instr() in traps.c - fold two-s if into 1 in do_trap. --- 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/Kconfig | 1 + xen/arch/riscv/traps.c | 35 ++++++++++++++++++++++++++++++++++- xen/common/bug.c | 1 + 3 files changed, 36 insertions(+), 1 deletion(-) diff --git a/xen/arch/riscv/Kconfig b/xen/arch/riscv/Kconfig index b4b354a778..f531e96657 100644 --- a/xen/arch/riscv/Kconfig +++ b/xen/arch/riscv/Kconfig @@ -1,6 +1,7 @@ config RISCV def_bool y select FUNCTION_ALIGNMENT_16B + select GENERIC_BUG_FRAME config RISCV_64 def_bool y diff --git a/xen/arch/riscv/traps.c b/xen/arch/riscv/traps.c index cb18b30ff2..6802827eb5 100644 --- a/xen/arch/riscv/traps.c +++ b/xen/arch/riscv/traps.c @@ -5,6 +5,7 @@ * RISC-V Trap handlers */ +#include #include #include @@ -103,7 +104,39 @@ static void do_unexpected_trap(const struct cpu_user_regs *regs) void do_trap(struct cpu_user_regs *cpu_regs) { - do_unexpected_trap(cpu_regs); + register_t pc = cpu_regs->sepc; + unsigned long cause = csr_read(CSR_SCAUSE); + + switch ( cause ) + { + /* + * ebreak is used as BUG_insn so when macros from are + * used, an exception with BREAKPOINT cause will be generated. + * + * ebreak triggers a debug trap, which starts in debug mode and is + * then filtered by every mode. A debugger will first handle the + * debug trap and check if ebreak was set by it or not. If not, + * CAUSE_BREAKPOINT will be generated for the mode where the ebreak + * instruction was executed. + */ + case CAUSE_BREAKPOINT: + if ( do_bug_frame(cpu_regs, pc) >= 0 ) + { + if ( !(is_kernel_text(pc) || is_kernel_inittext(pc)) ) + { + printk("Something wrong with PC: %#lx\n", pc); + die(); + } + + cpu_regs->sepc += GET_INSN_LENGTH(*(uint16_t *)pc); + } + + break; + + default: + do_unexpected_trap(cpu_regs); + break; + } } void vcpu_show_execution_state(struct vcpu *v) diff --git a/xen/common/bug.c b/xen/common/bug.c index b7c5d8fd4d..75cb35fcfa 100644 --- a/xen/common/bug.c +++ b/xen/common/bug.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include #include