From: Xianting Tian <xianting.tian@linux.alibaba.com> To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, wangkefeng.wang@huawei.com, philipp.tomsich@vrull.eu, ebiederm@xmission.com, heiko@sntech.de, vitaly.wool@konsulko.com, tongtiangen@huawei.com, guoren@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Xianting Tian <xianting.tian@linux.alibaba.com> Subject: [RESEND PATCH v2] RISC-V: Add fast call path of crash_kexec() Date: Mon, 6 Jun 2022 16:23:08 +0800 [thread overview] Message-ID: <20220606082308.2883458-1-xianting.tian@linux.alibaba.com> (raw) Currently, almost all archs (x86, arm64, mips...) support fast call of crash_kexec() when "regs && kexec_should_crash()" is true. But RISC-V not, it can only enter crash system via panic(). However panic() doesn't pass the regs of the real accident scene to crash_kexec(), it caused we can't get accurate backtrace via gdb, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 console_unlock () at kernel/printk/printk.c:2557 2557 if (do_cond_resched) (gdb) bt #0 console_unlock () at kernel/printk/printk.c:2557 #1 0x0000000000000000 in ?? () With the patch we can get the accurate backtrace, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 0xffffffe00063a4e0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81 81 *(int *)p = 0xdead; (gdb) (gdb) bt #0 0xffffffe00064d5c0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81 #1 0x0000000000000000 in ?? () Test code to produce NULL address dereference in test_crash.c, void *p = NULL; *(int *)p = 0xdead; Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Xianting Tian <xianting.tian@linux.alibaba.com> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> --- Changes from v1: - simplify the commit message --- arch/riscv/kernel/traps.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index fe92e119e6a3..e666ebfa2a64 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -16,6 +16,7 @@ #include <linux/mm.h> #include <linux/module.h> #include <linux/irq.h> +#include <linux/kexec.h> #include <asm/asm-prototypes.h> #include <asm/bug.h> @@ -44,6 +45,9 @@ void die(struct pt_regs *regs, const char *str) ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV); + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irq(&die_lock); -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Xianting Tian <xianting.tian@linux.alibaba.com> To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, wangkefeng.wang@huawei.com, philipp.tomsich@vrull.eu, ebiederm@xmission.com, heiko@sntech.de, vitaly.wool@konsulko.com, tongtiangen@huawei.com, guoren@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Xianting Tian <xianting.tian@linux.alibaba.com> Subject: [RESEND PATCH v2] RISC-V: Add fast call path of crash_kexec() Date: Mon, 6 Jun 2022 16:23:08 +0800 [thread overview] Message-ID: <20220606082308.2883458-1-xianting.tian@linux.alibaba.com> (raw) Currently, almost all archs (x86, arm64, mips...) support fast call of crash_kexec() when "regs && kexec_should_crash()" is true. But RISC-V not, it can only enter crash system via panic(). However panic() doesn't pass the regs of the real accident scene to crash_kexec(), it caused we can't get accurate backtrace via gdb, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 console_unlock () at kernel/printk/printk.c:2557 2557 if (do_cond_resched) (gdb) bt #0 console_unlock () at kernel/printk/printk.c:2557 #1 0x0000000000000000 in ?? () With the patch we can get the accurate backtrace, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 0xffffffe00063a4e0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81 81 *(int *)p = 0xdead; (gdb) (gdb) bt #0 0xffffffe00064d5c0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81 #1 0x0000000000000000 in ?? () Test code to produce NULL address dereference in test_crash.c, void *p = NULL; *(int *)p = 0xdead; Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Xianting Tian <xianting.tian@linux.alibaba.com> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> --- Changes from v1: - simplify the commit message --- arch/riscv/kernel/traps.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index fe92e119e6a3..e666ebfa2a64 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -16,6 +16,7 @@ #include <linux/mm.h> #include <linux/module.h> #include <linux/irq.h> +#include <linux/kexec.h> #include <asm/asm-prototypes.h> #include <asm/bug.h> @@ -44,6 +45,9 @@ void die(struct pt_regs *regs, const char *str) ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV); + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irq(&die_lock); -- 2.17.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next reply other threads:[~2022-06-06 8:23 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-06 8:23 Xianting Tian [this message] 2022-06-06 8:23 ` [RESEND PATCH v2] RISC-V: Add fast call path of crash_kexec() Xianting Tian 2022-07-22 0:11 ` Palmer Dabbelt 2022-07-22 0:11 ` Palmer Dabbelt 2022-07-22 3:41 ` tianxianting 2022-07-22 3:41 ` tianxianting
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