#!/bin/bash
#
# Translate stack dump function offsets.
#
# addr2line doesn't work with KASLR addresses.  This works similarly to
# addr2line, but instead takes the 'func+0x123' format as input:
#
#   $ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568
#   meminfo_proc_show+0x5/0x568:
#   meminfo_proc_show at fs/proc/meminfo.c:27
#
# If the address is part of an inlined function, the full inline call chain is
# printed:
#
#   $ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27
#   native_write_msr+0x6/0x27:
#   arch_static_branch at arch/x86/include/asm/msr.h:121
#    (inlined by) static_key_false at include/linux/jump_label.h:125
#    (inlined by) native_write_msr at arch/x86/include/asm/msr.h:125
#
# The function size after the '/' in the input is optional, but recommended.
# It's used to help disambiguate any duplicate symbol names, which can occur
# rarely.  If the size is omitted for a duplicate symbol then it's possible for
# multiple code sites to be printed:
#
#   $ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5
#   raw_ioctl+0x5/0x20:
#   raw_ioctl at drivers/char/raw.c:122
#
#   raw_ioctl+0x5/0xb1:
#   raw_ioctl at net/ipv4/raw.c:876
#
# Multiple addresses can be specified on a single command line:
#
#   $ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90
#   type_show+0x10/0x2d:
#   type_show at drivers/video/backlight/backlight.c:213
#
#   free_reserved_area+0x90/0x123:
#   free_reserved_area at mm/page_alloc.c:6429 (discriminator 2)


set -o errexit
set -o nounset

command -v awk >/dev/null 2>&1 || die "awk isn't installed"
command -v readelf >/dev/null 2>&1 || die "readelf isn't installed"
command -v addr2line >/dev/null 2>&1 || die "addr2line isn't installed"

usage() {
	echo "usage: faddr2line <object file> <func+offset> <func+offset>..." >&2
	exit 1
}

warn() {
	echo "$1" >&2
}

die() {
	echo "ERROR: $1" >&2
	exit 1
}

# Try to figure out the source directory prefix so we can remove it from the
# addr2line output.  HACK ALERT: This assumes that start_kernel() is in
# kernel/init.c!  This only works for vmlinux.  Otherwise it falls back to
# printing the absolute path.
find_dir_prefix() {
	local objfile=$1

	local start_kernel_addr=$(readelf -sW $objfile | awk '$8 == "start_kernel" {printf "0x%s", $2}')
	[[ -z $start_kernel_addr ]] && return

	local file_line=$(addr2line -e $objfile $start_kernel_addr)
	[[ -z $file_line ]] && return

	local prefix=${file_line%init/main.c:*}
	if [[ -z $prefix ]] || [[ $prefix = $file_line ]]; then
		return
	fi

	DIR_PREFIX=$prefix
	return 0
}

__faddr2line() {
	local objfile=$1
	local func_addr=$2
	local dir_prefix=$3
	local print_warnings=$4

	local func=${func_addr%+*}
	local offset=${func_addr#*+}
	offset=${offset%/*}
	local size=
	[[ $func_addr =~ "/" ]] && size=${func_addr#*/}

	if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then
		warn "bad func+offset $func_addr"
		DONE=1
		return
	fi

	# Go through each of the object's symbols which match the func name.
	# In rare cases there might be duplicates.
	while read symbol; do
		local fields=($symbol)
		local sym_base=0x${fields[0]}
		local sym_type=${fields[1]}
		local sym_end=0x${fields[3]}

		# calculate the size
		local sym_size=$(($sym_end - $sym_base))
		if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then
			warn "bad symbol size: base: $sym_base end: $sym_end"
			DONE=1
			return
		fi
		sym_size=0x$(printf %x $sym_size)

		# calculate the address
		local addr=$(($sym_base + $offset))
		if [[ -z $addr ]] || [[ $addr = 0 ]]; then
			warn "bad address: $sym_base + $offset"
			DONE=1
			return
		fi
		addr=0x$(printf %x $addr)

		# weed out non-function symbols
		if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then
			[[ $print_warnings = 1 ]] &&
				echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'"
			continue
		fi

		# if the user provided a size, make sure it matches the symbol's size
		if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then
			[[ $print_warnings = 1 ]] &&
				echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)"
			continue;
		fi

		# make sure the provided offset is within the symbol's range
		if [[ $offset -gt $sym_size ]]; then
			[[ $print_warnings = 1 ]] &&
				echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)"
			continue
		fi

		# separate multiple entries with a blank line
		[[ $FIRST = 0 ]] && echo
		FIRST=0

		# pass real address to addr2line
		echo "$func+$offset/$sym_size:"
		addr2line -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;"
		DONE=1

	done < <(nm -n $objfile | awk -v fn=$func '$3 == fn { found=1; line=$0; start=$1; next } found == 1 { found=0; print line, $1 }')
}

[[ $# -lt 2 ]] && usage

objfile=$1
[[ ! -f $objfile ]] && die "can't find objfile $objfile"
shift

DIR_PREFIX=supercalifragilisticexpialidocious
find_dir_prefix $objfile

FIRST=1
while [[ $# -gt 0 ]]; do
	func_addr=$1
	shift

	# print any matches found
	DONE=0
	__faddr2line $objfile $func_addr $DIR_PREFIX 0

	# if no match was found, print warnings
	if [[ $DONE = 0 ]]; then
		__faddr2line $objfile $func_addr $DIR_PREFIX 1
		warn "no match for $func_addr"
	fi
done
net-next.git/commit/net/kcm/Kconfig?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>6e978b22efa1db9f6e71b24440b5f1d93e968ee3</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/kcm/Kconfig?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>c666f7a26b860674848949e39a610222b0723f89</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/kcm/Kconfig?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>net/kcm/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/kcm/Kconfig?h=nds-private-remove&amp;id=3c223c19aea85d3dda1416c187915f4a30b04b1f'>3c223c19aea85d3dda1416c187915f4a30b04b1f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/kcm/Kconfig?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3&amp;id2=3c223c19aea85d3dda1416c187915f4a30b04b1f'>diff</a>)</td></tr></table>
<div class='commit-subject'>cpufreq: intel_pstate: Disable energy efficiency optimization</div><div class='commit-msg'>Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.

This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.

It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.

On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.

Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.

There are several ways to address this problem.

First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.

Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.

Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".

Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.

Signed-off-by: Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;
Reviewed-by: Len Brown &lt;len.brown@intel.com&gt;
Cc: 4.6+ &lt;stable@vger.kernel.org&gt; # 4.6+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>Diffstat</a> (limited to 'net/kcm/Kconfig')</div><table summary='diffstat' class='diffstat'>