mirror of
https://github.com/libretro/RetroArch.git
synced 2026-11-11 11:21:38 -10:00
libretroadmin
c26315f8b3
CODING-GUIDELINES puts a ceiling on a function's stack frame and nothing checked it. The frames this was written for were twelve kilobytes - a glyph chunk in each of four font drivers, and a batch of overlays in the Vulkan one - and they had been there for years, because a large local array compiles, and runs, on a machine with a desktop's stack. It is only a problem where the stack is smallest, which is the platform nobody runs the suite on. The sweep reads the release objects the menu-harness job already builds and sums the probes a prologue makes, since a frame that size is built a page at a time. Four functions are over and stay that way, each recorded with what it is: a CRT mode switch, the shader cache written and read once a pass, and a preview probe. Anything else over four kilobytes fails, and a recorded one that grows fails too. Checked by putting the twelve kilobyte glyph chunk back: the sweep names it and the run fails.
96 lines
3.3 KiB
Bash
Executable File
96 lines
3.3 KiB
Bash
Executable File
#!/bin/sh
|
|
# Every stack frame in the graphics objects, against the tree's limit.
|
|
#
|
|
# CODING-GUIDELINES puts a ceiling on a function's stack frame - two
|
|
# kilobytes inside libretro-common, four outside it - because the
|
|
# threads this code runs on do not all get a desktop's stack, and a
|
|
# frame that overruns one corrupts whatever is under it rather than
|
|
# failing. Nothing checked it: the frames this sweep was written for
|
|
# were twelve kilobytes, in four font paths and an overlay batch, and
|
|
# they had been there for years.
|
|
#
|
|
# A large local array is invisible in review and to every other lane -
|
|
# it compiles, it runs on a machine with eight megabytes of stack, and
|
|
# it is only a problem on the platform with the smallest one. This is
|
|
# the check that notices.
|
|
#
|
|
# Reads the release objects, so run it after a plain `make`. Functions
|
|
# allowed to exceed the ceiling are listed in stack-frame-sweep.ref
|
|
# with the size they measure; a change that grows one moves its line in
|
|
# the same commit, which is the moment to say why in the message.
|
|
set -e
|
|
cd "$(dirname "$0")/../../.."
|
|
|
|
OBJDIR=${OBJDIR:-obj-unix/release}
|
|
ref="$(dirname "$0")/stack-frame-sweep.ref"
|
|
limit=${LIMIT:-4096}
|
|
fail=0
|
|
|
|
if [ ! -d "$OBJDIR/gfx" ]; then
|
|
echo "skip: no objects in $OBJDIR (run make first)"
|
|
exit 0
|
|
fi
|
|
|
|
# A large frame is built by repeated probes of a page at a time, so the
|
|
# allocation is the sum of the subtractions a function makes, not the
|
|
# largest one.
|
|
for o in $(find "$OBJDIR/gfx" -name '*.o' | sort); do
|
|
objdump -d --no-show-raw-insn "$o" 2>/dev/null | awk -v obj="$o" -v lim="$limit" '
|
|
/^[0-9a-f]+ <.*>:/ {
|
|
if (fn != "" && total > lim)
|
|
printf "%s %s %d\n", obj, fn, total
|
|
fn = $2; sub(/^</, "", fn); sub(/>:$/, "", fn)
|
|
total = 0
|
|
next
|
|
}
|
|
/sub +\$0x[0-9a-f]+,%rsp/ {
|
|
# The hex is not at a fixed field: the address column shifts
|
|
# them, so take it out of the line rather than by index.
|
|
line = $0
|
|
sub(/^.*sub +\$0x/, "", line)
|
|
sub(/,%rsp.*$/, "", line)
|
|
hex = line
|
|
# mawk has no strtonum(); fold the hex by hand, and ignore the
|
|
# sign-extended constants an add-by-subtract produces.
|
|
n = 0; ok = 1
|
|
for (i = 1; i <= length(hex); i++) {
|
|
c = substr(hex, i, 1)
|
|
p = index("0123456789abcdef", c)
|
|
if (p == 0) { ok = 0; break }
|
|
n = n * 16 + (p - 1)
|
|
}
|
|
if (ok && n < 4194304) total += n
|
|
next
|
|
}
|
|
END {
|
|
if (fn != "" && total > lim)
|
|
printf "%s %s %d\n", obj, fn, total
|
|
}
|
|
'
|
|
done > /tmp/stack-frame-sweep.$$ || true
|
|
|
|
echo "== stack frames over $limit bytes =="
|
|
while read -r obj fn size; do
|
|
[ -n "$fn" ] || continue
|
|
want=$(awk -v f="$fn" '$1 == f { print $2 }' "$ref" 2>/dev/null)
|
|
if [ -z "$want" ]; then
|
|
echo "FAIL $fn ($size bytes) in $(basename "$obj")"
|
|
fail=1
|
|
elif [ "$size" -gt "$want" ]; then
|
|
echo "FAIL $fn grew to $size, recorded $want"
|
|
fail=1
|
|
else
|
|
echo "ok $fn ($size bytes, recorded $want)"
|
|
fi
|
|
done < /tmp/stack-frame-sweep.$$
|
|
rm -f /tmp/stack-frame-sweep.$$
|
|
|
|
if [ "$fail" = 1 ]; then
|
|
echo
|
|
echo "A function's stack frame is over the ceiling in CODING-GUIDELINES."
|
|
echo "Move the array off the frame, or record it in $ref with why."
|
|
exit 1
|
|
fi
|
|
echo "ok nothing else over $limit bytes"
|
|
exit 0
|