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linux/scripts/decode_stacktrace.sh

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decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
#!/bin/bash
# (c) 2014, Sasha Levin <sasha.levin@oracle.com>
#set -x
if [[ $# < 2 ]]; then
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
echo "Usage:"
echo " $0 [vmlinux] [base path] [modules path]"
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
exit 1
fi
vmlinux=$1
basepath=$2
modpath=$3
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
declare -A cache
declare -A modcache
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
parse_symbol() {
# The structure of symbol at this point is:
# ([name]+[offset]/[total length])
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
#
# For example:
# do_basic_setup+0x9c/0xbf
if [[ $module == "" ]] ; then
local objfile=$vmlinux
elif [[ "${modcache[$module]+isset}" == "isset" ]]; then
local objfile=${modcache[$module]}
else
[[ $modpath == "" ]] && return
local objfile=$(find "$modpath" -name $module.ko -print -quit)
[[ $objfile == "" ]] && return
modcache[$module]=$objfile
fi
# Remove the englobing parenthesis
symbol=${symbol#\(}
symbol=${symbol%\)}
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
# Strip the symbol name so that we could look it up
local name=${symbol%+*}
# Use 'nm vmlinux' to figure out the base address of said symbol.
# It's actually faster to call it every time than to load it
# all into bash.
if [[ "${cache[$module,$name]+isset}" == "isset" ]]; then
local base_addr=${cache[$module,$name]}
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
else
local base_addr=$(nm "$objfile" | grep -i ' t ' | awk "/ $name\$/ {print \$1}" | head -n1)
cache[$module,$name]="$base_addr"
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
fi
# Let's start doing the math to get the exact address into the
# symbol. First, strip out the symbol total length.
local expr=${symbol%/*}
# Now, replace the symbol name with the base address we found
# before.
expr=${expr/$name/0x$base_addr}
# Evaluate it to find the actual address
expr=$((expr))
local address=$(printf "%x\n" "$expr")
# Pass it to addr2line to get filename and line number
# Could get more than one result
if [[ "${cache[$module,$address]+isset}" == "isset" ]]; then
local code=${cache[$module,$address]}
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
else
local code=$(addr2line -i -e "$objfile" "$address")
cache[$module,$address]=$code
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
fi
# addr2line doesn't return a proper error code if it fails, so
# we detect it using the value it prints so that we could preserve
# the offset/size into the function and bail out
if [[ $code == "??:0" ]]; then
return
fi
# Strip out the base of the path
code=${code//$basepath/""}
# In the case of inlines, move everything to same line
code=${code//$'\n'/' '}
# Replace old address with pretty line numbers
symbol="$name ($code)"
}
decode_code() {
local scripts=`dirname "${BASH_SOURCE[0]}"`
echo "$1" | $scripts/decodecode
}
handle_line() {
local words
# Tokenize
read -a words <<<"$1"
# Remove hex numbers. Do it ourselves until it happens in the
# kernel
# We need to know the index of the last element before we
# remove elements because arrays are sparse
local last=$(( ${#words[@]} - 1 ))
for i in "${!words[@]}"; do
# Remove the address
if [[ ${words[$i]} =~ \[\<([^]]+)\>\] ]]; then
unset words[$i]
fi
# Format timestamps with tabs
if [[ ${words[$i]} == \[ && ${words[$i+1]} == *\] ]]; then
unset words[$i]
words[$i+1]=$(printf "[%13s\n" "${words[$i+1]}")
fi
done
if [[ ${words[$last]} =~ \[([^]]+)\] ]]; then
module=${words[$last]}
module=${module#\[}
module=${module%\]}
symbol=${words[$last-1]}
unset words[$last-1]
else
# The symbol is the last element, process it
symbol=${words[$last]}
module=
fi
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
unset words[$last]
parse_symbol # modifies $symbol
# Add up the line number to the symbol
echo "${words[@]}" "$symbol $module"
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
}
while read line; do
# Let's see if we have an address in the line
if [[ $line =~ \[\<([^]]+)\>\] ]]; then
# Translate address to line numbers
handle_line "$line"
# Is it a code line?
elif [[ $line == *Code:* ]]; then
decode_code "$line"
else
decode_stacktrace: make stack dump output useful again Right now when people try to report issues in the kernel they send stack dumps to eachother, which looks something like this: [ 6.906437] [<ffffffff811f0e90>] ? backtrace_test_irq_callback+0x20/0x20 [ 6.907121] [<ffffffff84388ce8>] dump_stack+0x52/0x7f [ 6.907640] [<ffffffff811f0ec8>] backtrace_regression_test+0x38/0x110 [ 6.908281] [<ffffffff813596a0>] ? proc_create_data+0xa0/0xd0 [ 6.908870] [<ffffffff870a8040>] ? proc_modules_init+0x22/0x22 [ 6.909480] [<ffffffff810020c2>] do_one_initcall+0xc2/0x1e0 [...] However, most of the text you get is pure garbage. The only useful thing above is the function name. Due to the amount of different kernel code versions and various configurations being used, the kernel address and the offset into the function are not really helpful in determining where the problem actually occured. Too often the result of someone looking at a stack dump is asking the person who sent it for a translation for one or more 'addr2line' translations. Which slows down the entire process of debugging the issue (and really annoying). The decode_stacktrace script is an attempt to make the output more useful and easy to work with by translating all kernel addresses in the stack dump into line numbers. Which means that the stack dump would look like this: [ 635.148361] dump_stack (lib/dump_stack.c:52) [ 635.149127] warn_slowpath_common (kernel/panic.c:418) [ 635.150214] warn_slowpath_null (kernel/panic.c:453) [ 635.151031] _oalloc_pages_slowpath+0x6a/0x7d0 [ 635.152171] ? zone_watermark_ok (mm/page_alloc.c:1728) [ 635.152988] ? get_page_from_freelist (mm/page_alloc.c:1939) [ 635.154766] __alloc_pages_nodemask (mm/page_alloc.c:2766) It's pretty obvious why this is better than the previous stack dump before. Usage is pretty simple: ./decode_stacktrace.sh [vmlinux] [base path] Where vmlinux is the vmlinux to extract line numbers from and base path is the path that points to the root of the build tree, for example: ./decode_stacktrace.sh vmlinux /home/sasha/linux/ < input.log > output.log The stack trace should be piped through it (I, for example, just pipe the output of the serial console of my KVM test box through it). Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 15:39:23 +00:00
# Nothing special in this line, show it as is
echo "$line"
fi
done