target/riscv/riscv-qmp-cmds.c: coverity-related fixes

Coverity CID 1641401 reports that, in reg_is_ulong_integer(), we're
dereferencing a NULL pointer in "reg1" when using it in strcasecmp()
call. A similar case is reported with CID 1641393.

In theory that will never happen - it's guaranteed that both "reg1" and
"reg2" is non-NULL because we're retrieving them in compile-time from
static arrays. Coverity doesn't know that though.

To make Coverity happier and add a bit more clarity in the code,
g_assert() each token to make it clear that those 2 values aren't
supposed to be NULL ever. Do that in both reg_is_ulong_integer() and
reg_is_u64_fpu().

We're also taking the opportunity to implement suggestions made by Peter
in [1] in both functions:

- use g_strsplit() instead of strtok();
- use g_ascii_strcasecmp() instead of strcasecmp().

[1] https://lore.kernel.org/qemu-devel/CAFEAcA_y4bwd9GANbXnpTy2mv80Vg_jp+A-VkQS5V6f0+BFRAA@mail.gmail.com/

Coverity: CID 1641393, 1641401
Fixes: e06d209aa6 ("target/riscv: implement MonitorDef HMP API")
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20251022125643.588947-1-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/riscv-qmp-cmds.c b/target/riscv/riscv-qmp-cmds.c
index c499f9b9a7d6b99d4e9536af67b80b26ec83b3c9..d5e9bec0f86ffb31ac3e43f574985cb59a8dddc3 100644 (file)
--- a/target/riscv/riscv-qmp-cmds.c
+++ b/target/riscv/riscv-qmp-cmds.c
@@ -273,12 +273,13 @@ static bool reg_is_ulong_integer(CPURISCVState *env, const char *name,
     }
 
     for (int i = 0; i < 32; i++) {
-        g_autofree char *reg_name = g_strdup(reg_names[i]);
-        char *reg1 = strtok(reg_name, "/");
-        char *reg2 = strtok(NULL, "/");
+        g_auto(GStrv) reg_name = g_strsplit(reg_names[i], "/", 2);
 
-        if (strcasecmp(reg1, name) == 0 ||
-            (reg2 && strcasecmp(reg2, name) == 0)) {
+        g_assert(reg_name[0]);
+        g_assert(reg_name[1]);
+
+        if (g_ascii_strcasecmp(reg_name[0], name) == 0 ||
+            g_ascii_strcasecmp(reg_name[1], name) == 0) {
             *val = vals[i];
             return true;
         }
@@ -294,12 +295,13 @@ static bool reg_is_u64_fpu(CPURISCVState *env, const char *name, uint64_t *val)
     }
 
     for (int i = 0; i < 32; i++) {
-        g_autofree char *reg_name = g_strdup(riscv_fpr_regnames[i]);
-        char *reg1 = strtok(reg_name, "/");
-        char *reg2 = strtok(NULL, "/");
+        g_auto(GStrv) reg_name = g_strsplit(riscv_fpr_regnames[i], "/", 2);
+
+        g_assert(reg_name[0]);
+        g_assert(reg_name[1]);
 
-        if (strcasecmp(reg1, name) == 0 ||
-            (reg2 && strcasecmp(reg2, name) == 0)) {
+        if (g_ascii_strcasecmp(reg_name[0], name) == 0 ||
+            g_ascii_strcasecmp(reg_name[1], name) == 0) {
             *val = env->fpr[i];
             return true;
         }