From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- arch/arm/kernel/perf_callchain.c | 137 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 arch/arm/kernel/perf_callchain.c (limited to 'arch/arm/kernel/perf_callchain.c') diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c new file mode 100644 index 000000000..08e43a32a --- /dev/null +++ b/arch/arm/kernel/perf_callchain.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM callchain support + * + * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles + * Copyright (C) 2010 ARM Ltd., Will Deacon + * + * This code is based on the ARM OProfile backtrace code. + */ +#include +#include + +#include + +/* + * The registers we're interested in are at the end of the variable + * length saved register structure. The fp points at the end of this + * structure so the address of this struct is: + * (struct frame_tail *)(xxx->fp)-1 + * + * This code has been adapted from the ARM OProfile support. + */ +struct frame_tail { + struct frame_tail __user *fp; + unsigned long sp; + unsigned long lr; +} __attribute__((packed)); + +/* + * Get the return address for a single stackframe and return a pointer to the + * next frame tail. + */ +static struct frame_tail __user * +user_backtrace(struct frame_tail __user *tail, + struct perf_callchain_entry_ctx *entry) +{ + struct frame_tail buftail; + unsigned long err; + + if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) + return NULL; + + pagefault_disable(); + err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail)); + pagefault_enable(); + + if (err) + return NULL; + + perf_callchain_store(entry, buftail.lr); + + /* + * Frame pointers should strictly progress back up the stack + * (towards higher addresses). + */ + if (tail + 1 >= buftail.fp) + return NULL; + + return buftail.fp - 1; +} + +void +perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) +{ + struct frame_tail __user *tail; + + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + /* We don't support guest os callchain now */ + return; + } + + perf_callchain_store(entry, regs->ARM_pc); + + if (!current->mm) + return; + + tail = (struct frame_tail __user *)regs->ARM_fp - 1; + + while ((entry->nr < entry->max_stack) && + tail && !((unsigned long)tail & 0x3)) + tail = user_backtrace(tail, entry); +} + +/* + * Gets called by walk_stackframe() for every stackframe. This will be called + * whist unwinding the stackframe and is like a subroutine return so we use + * the PC. + */ +static int +callchain_trace(struct stackframe *fr, + void *data) +{ + struct perf_callchain_entry_ctx *entry = data; + perf_callchain_store(entry, fr->pc); + return 0; +} + +void +perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) +{ + struct stackframe fr; + + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + /* We don't support guest os callchain now */ + return; + } + + arm_get_current_stackframe(regs, &fr); + walk_stackframe(&fr, callchain_trace, entry); +} + +unsigned long perf_instruction_pointer(struct pt_regs *regs) +{ + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) + return perf_guest_cbs->get_guest_ip(); + + return instruction_pointer(regs); +} + +unsigned long perf_misc_flags(struct pt_regs *regs) +{ + int misc = 0; + + if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) { + if (perf_guest_cbs->is_user_mode()) + misc |= PERF_RECORD_MISC_GUEST_USER; + else + misc |= PERF_RECORD_MISC_GUEST_KERNEL; + } else { + if (user_mode(regs)) + misc |= PERF_RECORD_MISC_USER; + else + misc |= PERF_RECORD_MISC_KERNEL; + } + + return misc; +} -- cgit v1.2.3