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Prevent crash on division by zero

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Currently, attempting to divide by zero in an integer expression in a dts
file will cause dtc to crash with a division by zero (SIGFPE).

This patch corrects this to properly detect this case and raise an error.

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
David Gibson 2016-01-03 22:27:32 +11:00
parent d0b3ab0a0f
commit 1937095588
3 changed files with 16 additions and 1 deletions
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10
dtc-parser.y
View file

@ -410,7 +410,15 @@ integer_add:
integer_mul: integer_mul:
integer_mul '*' integer_unary { $$ = $1 * $3; } integer_mul '*' integer_unary { $$ = $1 * $3; }
| integer_mul '/' integer_unary { $$ = $1 / $3; } | integer_mul '/' integer_unary
{
if ($3 != 0) {
$$ = $1 / $3;
} else {
ERROR(&@$, "Division by zero");
$$ = 0;
}
}
| integer_mul '%' integer_unary { $$ = $1 % $3; } | integer_mul '%' integer_unary { $$ = $1 % $3; }
| integer_unary | integer_unary
; ;

5
tests/division-by-zero.dts Normal file
View file

@ -0,0 +1,5 @@
/dts-v1/;
/ {
prop = < (1/0) >;
};

2
tests/run_tests.sh
View file

@ -289,6 +289,8 @@ libfdt_tests () {
run_test dtbs_equal_ordered embedded_nul.test.dtb embedded_nul_equiv.test.dtb run_test dtbs_equal_ordered embedded_nul.test.dtb embedded_nul_equiv.test.dtb
run_dtc_test -I dts -O dtb bad-size-cells.dts run_dtc_test -I dts -O dtb bad-size-cells.dts
run_wrap_error_test $DTC division-by-zero.dts
} }
dtc_tests () { dtc_tests () {