diff options
-rw-r--r-- | arch/xtensa/include/asm/stacktrace.h | 8 | ||||
-rw-r--r-- | arch/xtensa/kernel/stacktrace.c | 167 | ||||
-rw-r--r-- | arch/xtensa/oprofile/backtrace.c | 158 |
3 files changed, 182 insertions, 151 deletions
diff --git a/arch/xtensa/include/asm/stacktrace.h b/arch/xtensa/include/asm/stacktrace.h index 6a05fcb..fe06e8e 100644 --- a/arch/xtensa/include/asm/stacktrace.h +++ b/arch/xtensa/include/asm/stacktrace.h @@ -33,4 +33,12 @@ void walk_stackframe(unsigned long *sp, int (*fn)(struct stackframe *frame, void *data), void *data); +void xtensa_backtrace_kernel(struct pt_regs *regs, unsigned int depth, + int (*kfn)(struct stackframe *frame, void *data), + int (*ufn)(struct stackframe *frame, void *data), + void *data); +void xtensa_backtrace_user(struct pt_regs *regs, unsigned int depth, + int (*ufn)(struct stackframe *frame, void *data), + void *data); + #endif /* _XTENSA_STACKTRACE_H */ diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c index 7d2c317..7538d80 100644 --- a/arch/xtensa/kernel/stacktrace.c +++ b/arch/xtensa/kernel/stacktrace.c @@ -1,11 +1,12 @@ /* - * arch/xtensa/kernel/stacktrace.c + * Kernel and userspace stack tracing. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2001 - 2013 Tensilica Inc. + * Copyright (C) 2015 Cadence Design Systems Inc. */ #include <linux/export.h> #include <linux/sched.h> @@ -13,6 +14,170 @@ #include <asm/stacktrace.h> #include <asm/traps.h> +#include <asm/uaccess.h> + +#if IS_ENABLED(CONFIG_OPROFILE) || IS_ENABLED(CONFIG_PERF_EVENTS) + +/* Address of common_exception_return, used to check the + * transition from kernel to user space. + */ +extern int common_exception_return; + +/* A struct that maps to the part of the frame containing the a0 and + * a1 registers. + */ +struct frame_start { + unsigned long a0; + unsigned long a1; +}; + +void xtensa_backtrace_user(struct pt_regs *regs, unsigned int depth, + int (*ufn)(struct stackframe *frame, void *data), + void *data) +{ + unsigned long windowstart = regs->windowstart; + unsigned long windowbase = regs->windowbase; + unsigned long a0 = regs->areg[0]; + unsigned long a1 = regs->areg[1]; + unsigned long pc = regs->pc; + struct stackframe frame; + int index; + + if (!depth--) + return; + + frame.pc = pc; + frame.sp = a1; + + if (pc == 0 || pc >= TASK_SIZE || ufn(&frame, data)) + return; + + /* Two steps: + * + * 1. Look through the register window for the + * previous PCs in the call trace. + * + * 2. Look on the stack. + */ + + /* Step 1. */ + /* Rotate WINDOWSTART to move the bit corresponding to + * the current window to the bit #0. + */ + windowstart = (windowstart << WSBITS | windowstart) >> windowbase; + + /* Look for bits that are set, they correspond to + * valid windows. + */ + for (index = WSBITS - 1; (index > 0) && depth; depth--, index--) + if (windowstart & (1 << index)) { + /* Get the PC from a0 and a1. */ + pc = MAKE_PC_FROM_RA(a0, pc); + /* Read a0 and a1 from the + * corresponding position in AREGs. + */ + a0 = regs->areg[index * 4]; + a1 = regs->areg[index * 4 + 1]; + + frame.pc = pc; + frame.sp = a1; + + if (pc == 0 || pc >= TASK_SIZE || ufn(&frame, data)) + return; + } + + /* Step 2. */ + /* We are done with the register window, we need to + * look through the stack. + */ + if (!depth) + return; + + /* Start from the a1 register. */ + /* a1 = regs->areg[1]; */ + while (a0 != 0 && depth--) { + struct frame_start frame_start; + /* Get the location for a1, a0 for the + * previous frame from the current a1. + */ + unsigned long *psp = (unsigned long *)a1; + + psp -= 4; + + /* Check if the region is OK to access. */ + if (!access_ok(VERIFY_READ, psp, sizeof(frame_start))) + return; + /* Copy a1, a0 from user space stack frame. */ + if (__copy_from_user_inatomic(&frame_start, psp, + sizeof(frame_start))) + return; + + pc = MAKE_PC_FROM_RA(a0, pc); + a0 = frame_start.a0; + a1 = frame_start.a1; + + frame.pc = pc; + frame.sp = a1; + + if (pc == 0 || pc >= TASK_SIZE || ufn(&frame, data)) + return; + } +} +EXPORT_SYMBOL(xtensa_backtrace_user); + +void xtensa_backtrace_kernel(struct pt_regs *regs, unsigned int depth, + int (*kfn)(struct stackframe *frame, void *data), + int (*ufn)(struct stackframe *frame, void *data), + void *data) +{ + unsigned long pc = regs->depc > VALID_DOUBLE_EXCEPTION_ADDRESS ? + regs->depc : regs->pc; + unsigned long sp_start, sp_end; + unsigned long a0 = regs->areg[0]; + unsigned long a1 = regs->areg[1]; + + sp_start = a1 & ~(THREAD_SIZE - 1); + sp_end = sp_start + THREAD_SIZE; + + /* Spill the register window to the stack first. */ + spill_registers(); + + /* Read the stack frames one by one and create the PC + * from the a0 and a1 registers saved there. + */ + while (a1 > sp_start && a1 < sp_end && depth--) { + struct stackframe frame; + unsigned long *psp = (unsigned long *)a1; + + frame.pc = pc; + frame.sp = a1; + + if (kernel_text_address(pc) && kfn(&frame, data)) + return; + + if (pc == (unsigned long)&common_exception_return) { + regs = (struct pt_regs *)a1; + if (user_mode(regs)) { + if (ufn == NULL) + return; + xtensa_backtrace_user(regs, depth, ufn, data); + return; + } + a0 = regs->areg[0]; + a1 = regs->areg[1]; + continue; + } + + sp_start = a1; + + pc = MAKE_PC_FROM_RA(a0, pc); + a0 = *(psp - 4); + a1 = *(psp - 3); + } +} +EXPORT_SYMBOL(xtensa_backtrace_kernel); + +#endif void walk_stackframe(unsigned long *sp, int (*fn)(struct stackframe *frame, void *data), diff --git a/arch/xtensa/oprofile/backtrace.c b/arch/xtensa/oprofile/backtrace.c index 5f03a59..8f95203 100644 --- a/arch/xtensa/oprofile/backtrace.c +++ b/arch/xtensa/oprofile/backtrace.c @@ -2,168 +2,26 @@ * @file backtrace.c * * @remark Copyright 2008 Tensilica Inc. + * Copyright (C) 2015 Cadence Design Systems Inc. * @remark Read the file COPYING * */ #include <linux/oprofile.h> -#include <linux/sched.h> -#include <linux/mm.h> #include <asm/ptrace.h> -#include <asm/uaccess.h> -#include <asm/traps.h> +#include <asm/stacktrace.h> -/* Address of common_exception_return, used to check the - * transition from kernel to user space. - */ -extern int common_exception_return; - -/* A struct that maps to the part of the frame containing the a0 and - * a1 registers. - */ -struct frame_start { - unsigned long a0; - unsigned long a1; -}; - -static void xtensa_backtrace_user(struct pt_regs *regs, unsigned int depth) -{ - unsigned long windowstart = regs->windowstart; - unsigned long windowbase = regs->windowbase; - unsigned long a0 = regs->areg[0]; - unsigned long a1 = regs->areg[1]; - unsigned long pc = MAKE_PC_FROM_RA(a0, regs->pc); - int index; - - /* First add the current PC to the trace. */ - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - - /* Two steps: - * - * 1. Look through the register window for the - * previous PCs in the call trace. - * - * 2. Look on the stack. - */ - - /* Step 1. */ - /* Rotate WINDOWSTART to move the bit corresponding to - * the current window to the bit #0. - */ - windowstart = (windowstart << WSBITS | windowstart) >> windowbase; - - /* Look for bits that are set, they correspond to - * valid windows. - */ - for (index = WSBITS - 1; (index > 0) && depth; depth--, index--) - if (windowstart & (1 << index)) { - /* Read a0 and a1 from the - * corresponding position in AREGs. - */ - a0 = regs->areg[index * 4]; - a1 = regs->areg[index * 4 + 1]; - /* Get the PC from a0 and a1. */ - pc = MAKE_PC_FROM_RA(a0, pc); - - /* Add the PC to the trace. */ - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - } - - /* Step 2. */ - /* We are done with the register window, we need to - * look through the stack. - */ - if (depth > 0) { - /* Start from the a1 register. */ - /* a1 = regs->areg[1]; */ - while (a0 != 0 && depth--) { - - struct frame_start frame_start; - /* Get the location for a1, a0 for the - * previous frame from the current a1. - */ - unsigned long *psp = (unsigned long *)a1; - psp -= 4; - - /* Check if the region is OK to access. */ - if (!access_ok(VERIFY_READ, psp, sizeof(frame_start))) - return; - /* Copy a1, a0 from user space stack frame. */ - if (__copy_from_user_inatomic(&frame_start, psp, - sizeof(frame_start))) - return; - - a0 = frame_start.a0; - a1 = frame_start.a1; - pc = MAKE_PC_FROM_RA(a0, pc); - - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - } - } -} - -static void xtensa_backtrace_kernel(struct pt_regs *regs, unsigned int depth) +static int xtensa_backtrace_cb(struct stackframe *frame, void *data) { - unsigned long pc = regs->pc; - unsigned long *psp; - unsigned long sp_start, sp_end; - unsigned long a0 = regs->areg[0]; - unsigned long a1 = regs->areg[1]; - - sp_start = a1 & ~(THREAD_SIZE-1); - sp_end = sp_start + THREAD_SIZE; - - /* Spill the register window to the stack first. */ - spill_registers(); - - /* Read the stack frames one by one and create the PC - * from the a0 and a1 registers saved there. - */ - while (a1 > sp_start && a1 < sp_end && depth--) { - pc = MAKE_PC_FROM_RA(a0, pc); - - /* Add the PC to the trace. */ - oprofile_add_trace(pc); - if (pc == (unsigned long) &common_exception_return) { - regs = (struct pt_regs *)a1; - if (user_mode(regs)) { - pc = regs->pc; - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - return xtensa_backtrace_user(regs, depth); - } - a0 = regs->areg[0]; - a1 = regs->areg[1]; - continue; - } - - psp = (unsigned long *)a1; - - a0 = *(psp - 4); - a1 = *(psp - 3); - - if (a1 <= (unsigned long)psp) - return; - - } - return; + oprofile_add_trace(frame->pc); + return 0; } void xtensa_backtrace(struct pt_regs * const regs, unsigned int depth) { if (user_mode(regs)) - xtensa_backtrace_user(regs, depth); + xtensa_backtrace_user(regs, depth, xtensa_backtrace_cb, NULL); else - xtensa_backtrace_kernel(regs, depth); + xtensa_backtrace_kernel(regs, depth, xtensa_backtrace_cb, + xtensa_backtrace_cb, NULL); } |