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(-) 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
