On Wed, Sep 13, 2023 at 01:59:57PM +0200, Ahmad Fatoum wrote:
> So far signed integers in binary comparisons were accepted, but compared
> unsigned resulting in [ "-1" -gt 0 ] returning true.
>
> Rework this, so that:
>
> - If one side is signed, the comparison is signed
> - If both sides are unsigned, the comparison is unsigned
>
> The latter is not required by POSIX, but it ensures that we don't break
> users who so far did comparisons with integers > LONG_MAX without issue.
>
> While at it, we start checking that the arguments in arithmetic
> comparisons are indeed integers. This has the result that e.g.
> [ "1x" -eq "1x" ] will no longer return success, but that aligns us with
> usual shell behavior and protects the users from silent truncation when
> a number > LONG_MAX is compared with a negative number.
>
> Signed-off-by: Ahmad Fatoum <[email protected]>
> ---
> commands/test.c | 66 ++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 51 insertions(+), 15 deletions(-)
Applied, thanks
Sascha
>
> diff --git a/commands/test.c b/commands/test.c
> index 1130bf2e5bd6..13005b97deb3 100644
> --- a/commands/test.c
> +++ b/commands/test.c
> @@ -78,11 +78,56 @@ static int string_comp(const char *left_op, const char
> *right_op, bool bash_test
> return strcmp(left_op, right_op);
> }
>
> +static int parse_number(const char *str, long *num, bool signedcmp)
> +{
> + int ret;
> +
> + ret = signedcmp ? kstrtol(str, 0, num) : kstrtoul(str, 0, num);
> + if (ret)
> + printf("test: %s: integer expression expected\n", str);
> +
> + return ret;
> +}
> +
> +#define __do_arith_cmp(x, op, y, signedcmp) \
> + ((signedcmp) ? (long)(x) op (long)(y) : (x) op (y))
> +
> +static int arith_comp(const char *a_str, const char *b_str, int op)
> +{
> + ulong a, b;
> + bool signedcmp = a_str[0] == '-' || b_str[0] == '-';
> + int ret;
> +
> + ret = parse_number(a_str, &a, signedcmp);
> + if (ret)
> + return ret;
> +
> + ret = parse_number(b_str, &b, signedcmp);
> + if (ret)
> + return ret;
> +
> + switch (op) {
> + case OPT_ARITH_EQUAL:
> + return __do_arith_cmp(a, ==, b, signedcmp);
> + case OPT_ARITH_NOT_EQUAL:
> + return __do_arith_cmp(a, !=, b, signedcmp);
> + case OPT_ARITH_GREATER_EQUAL:
> + return __do_arith_cmp(a, >=, b, signedcmp);
> + case OPT_ARITH_GREATER_THAN:
> + return __do_arith_cmp(a, >, b, signedcmp);
> + case OPT_ARITH_LESS_EQUAL:
> + return __do_arith_cmp(a, <=, b, signedcmp);
> + case OPT_ARITH_LESS_THAN:
> + return __do_arith_cmp(a, <, b, signedcmp);
> + }
> +
> + return -EINVAL;
> +}
> +
> static int do_test(int argc, char *argv[])
> {
> char **ap;
> int left, adv, expr, last_expr, neg, last_cmp, opt, zero;
> - ulong a, b;
> struct stat statbuf;
> bool bash_test = false;
>
> @@ -199,9 +244,8 @@ static int do_test(int argc, char *argv[])
> if (left < 3)
> break;
>
> - a = simple_strtol(ap[0], NULL, 0);
> - b = simple_strtol(ap[2], NULL, 0);
> - switch (parse_opt(ap[1])) {
> + opt = parse_opt(ap[1]);
> + switch (opt) {
> case OPT_EQUAL:
> case OPT_EQUAL_BASH:
> expr = string_comp(ap[0], ap[2], bash_test) ==
> 0;
> @@ -210,22 +254,14 @@ static int do_test(int argc, char *argv[])
> expr = string_comp(ap[0], ap[2], bash_test) !=
> 0;
> break;
> case OPT_ARITH_EQUAL:
> - expr = a == b;
> - break;
> case OPT_ARITH_NOT_EQUAL:
> - expr = a != b;
> - break;
> case OPT_ARITH_LESS_THAN:
> - expr = a < b;
> - break;
> case OPT_ARITH_LESS_EQUAL:
> - expr = a <= b;
> - break;
> case OPT_ARITH_GREATER_THAN:
> - expr = a > b;
> - break;
> case OPT_ARITH_GREATER_EQUAL:
> - expr = a >= b;
> + expr = arith_comp(ap[0], ap[2], opt);
> + if (expr < 0)
> + return 1;
> break;
> default:
> expr = 1;
> --
> 2.39.2
>
>
>
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