[PATCH] lib: sbi: check result of pmp_get() in is_pmp_entry_mapped()

[Carlos López]

pmp_get() may return an error if the given entry, given by the caller
of is_pmp_entry_mapped(), is invalid. This results in the output
parameters for pmp_get() being uninitialized. To avoid using garbage
values, check the result and return early if necessary.

This issue is not being hit because at the moment
is_pmp_entry_mapped() is only being called from a single site with a
valid hardcoded value.

Signed-off-by: Carlos López <carlos.lopezr4096 at gmail.com>
---
 lib/sbi/riscv_asm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/sbi/riscv_asm.c b/lib/sbi/riscv_asm.c
index 05b8c7c..c7d75ac 100644
--- a/lib/sbi/riscv_asm.c
+++ b/lib/sbi/riscv_asm.c
@@ -291,7 +291,8 @@ int is_pmp_entry_mapped(unsigned long entry)
 	unsigned long addr;
 	unsigned long log2len;
 
-	pmp_get(entry, &prot, &addr, &log2len);
+	if (pmp_get(entry, &prot, &addr, &log2len) != 0)
+		return false;
 
 	/* If address matching bits are non-zero, the entry is enable */
 	if (prot & PMP_A)
-- 
2.39.2