ARM Cortex Whitelist & Cumulative Blacklist

Applies all information about vulnerabilities of ARM Cortex processors (from https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability).

Whitelist & blacklist approach, using both vulnerable and non vulnerable status for each identified CPU, with vulnerabilities tracked cumulatively for multi CPU systems.
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Rob Gill 2018-06-12 22:54:20 +10:00 committed by GitHub
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commit e7cf189d85
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1 changed files with 44 additions and 52 deletions

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@ -341,70 +341,62 @@ is_cpu_vulnerable()
if [ -n "$cpupart" ] && [ -n "$cpuarch" ]; then
# Cortex-R7 and Cortex-R8 are real-time and only used in medical devices or such
# I can't find their CPU part number, but it's probably not that useful anyway
# model R7 R8 A8 A9 A12 A15 A17 A57 A72 A73 A75
# part ? ? 0xc08 0xc09 0xc0c 0xc0f 0xc0e 0xd07 0xd08 0xd09 0xd0a
# arch 7? 7? 7 7 7 7 7 8 8 8 8
# model R7 R8 A9 A15 A17 A57 A72 A73 A75
# part ? ? 0xc09 0xc0f 0xc0e 0xd07 0xd08 0xd09 0xd0a
# arch 7? 7? 7 7 7 8 8 8 8
#
# variant 1 & variant 2
if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c08|c09|c0c|c0f|c0e)$'; then
# armv7 vulnerable chips
_debug "checking cpu$i: this armv7 vulnerable to spectre 1 & 2"
# Whitelist identified non-vulnerable processors, use vulnerability information from
# https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability
#
# Maintain cumulative check of vulnerabilities -
# if at least one of the cpu is vulnerable, then the system is vulnerable
if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c0[89ce])$'; then
variant1=vuln
variant2=vuln
[ -z "$variant3" ] && variant3=immune
[ -z "$variant3a" ] && variant3a=immune
[ -z "$variant4" ] && variant4=immune
_debug "checking cpu$i: this armv7 non vulnerable to variants 3, 3a & 4"
elif [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c0f)$'; then
variant1=vuln
variant2=vuln
[ -z "$variant3" ] && variant3=immune
variant3=vuln
[ -z "$variant4" ] && variant4=immune
_debug "checking cpu$i: this armv7 non vulnerable to variants 3 & 4"
elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08)$'; then
variant1=vuln
variant2=vuln
variant3=vuln
[ -z "$variant3a" ] && variant3a=immune
[ -z "$variant4" ] && variant4=immune
_debug "checking cpu$i: this armv7 non vulnerable to variants 3a & 4"
elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d09|d0b)$'; then
variant1=vuln
variant2=vuln
elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
# armv8 vulnerable chips
_debug "checking cpu$i: this armv8 vulnerable to spectre 1 & 2"
variant1=vuln
variant2=vuln
else
_debug "checking cpu$i: this arm non vulnerable to 1 & 2"
# others are not vulnerable
[ -z "$variant1" ] && variant1=immune
[ -z "$variant2" ] && variant2=immune
fi
# for variant3, only A75 is vulnerable
if [ "$cpuarch" = 8 ] && [ "$cpupart" = 0xd0a ]; then
_debug "checking cpu$i: arm A75 vulnerable to meltdown"
variant3=vuln
else
_debug "checking cpu$i: this arm non vulnerable to meltdown"
[ -z "$variant3" ] && variant3=immune
fi
# for variant3a, only A15/A57/A72 are vulnerable
if [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(c0f|d07|d0a)$'; then
_debug "checking cpu$i: arm A15-A57-A72 vulnerable to variant3a"
variant3a=vuln
else
_debug "checking cpu$i: this arm non vulnerable to variant3a"
[ -z "$variant3a" ] && variant3a=immune
fi
# for variant4, arch 7 immune, arch 8 A57-72-73-75-76 are vulnerable
if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c0[89cfe])$'; then
_debug "checking cpu$i: arm A8-A9-A12-A15-A17 non vulnerable to variant4"
variant4=immune
elif [ "$cpuarch" = 8 ]; then
_debug "checking cpu$i: arm A57-A72-A73-A75-A76 vulnerable to variant4"
variant4=vuln
_debug "checking cpu$i: this armv8 non vulnerable to variants 3 & 3a"
elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(c0a)$'; then
variant1=vuln
variant2=vuln
variant3=vuln
[ -z "$variant3a" ] && variant3a=immune
variant4=vuln
_debug "checking cpu$i: this armv8 non vulnerable to variant 3a"
else
_debug "checking cpu$i: unknown arm processor assumed vulnerable to variant4"
[ -z "$variant4" ] && variant4=vuln
variant1=vuln
variant2=vuln
variant3=vuln
variant3a=vuln
variant4=vuln
_debug "checking cpu$i: this arm unknown"
fi
fi
_debug "is_cpu_vulnerable: for cpu$i and so far, we have <$variant1> <$variant2> <$variant3> <$variant3a> <$variant4>"
done
fi
# from the information we have for now, it seems that CPUs that are vulnerable to variant1 are also vulnerable to variant4
[ -z "$variant4" ] && variant4=$variant1
_debug "is_cpu_vulnerable: temp results are <$variant1> <$variant2> <$variant3> <$variant3a> <$variant4>"
# if at least one of the cpu is vulnerable, then the system is vulnerable
[ "$variant1" = "immune" ] && variant1=1 || variant1=0
[ "$variant2" = "immune" ] && variant2=1 || variant2=0
[ "$variant3" = "immune" ] && variant3=1 || variant3=0
[ "$variant3a" = "immune" ] && variant3a=1 || variant3a=0
[ "$variant4" = "immune" ] && variant4=1 || variant4=0
_debug "is_cpu_vulnerable: final results are <$variant1> <$variant2> <$variant3> <$variant3a> <$variant4>"
is_cpu_vulnerable_cached=1
_is_cpu_vulnerable_cached "$1"