[PATCH v2] lmb: Correctly unmap and free memory on errors

[Ilias Apalodimas]

We never free and unmap the memory on errors and we never unmap it when
freeing it. The latter won't cause any problems even on sandbox, but for
consistency always use unmap_sysmem()

Fixes: commit 22f2c9ed9f53 ("efi: memory: use the lmb API's for allocating and freeing memory")
Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
Changes since v1:
- added r-b tags
- reword the commit message
- rebase on -master

 lib/efi_loader/efi_memory.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index d2f5d563f2a0..e493934c7131 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -451,7 +451,7 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
 				enum efi_memory_type memory_type,
 				efi_uintn_t pages, uint64_t *memory)
 {
-	u64 len;
+	u64 efi_addr, len;
 	uint flags;
 	efi_status_t ret;
 	phys_addr_t addr;
@@ -499,14 +499,17 @@ efi_status_t efi_allocate_pages(enum efi_allocate_type type,
 		return EFI_INVALID_PARAMETER;
 	}

-	addr = (u64)(uintptr_t)map_sysmem(addr, 0);
+	efi_addr = (u64)(uintptr_t)map_sysmem(addr, 0);
 	/* Reserve that map in our memory maps */
-	ret = efi_add_memory_map_pg(addr, pages, memory_type, true);
-	if (ret != EFI_SUCCESS)
+	ret = efi_add_memory_map_pg(efi_addr, pages, memory_type, true);
+	if (ret != EFI_SUCCESS) {
 		/* Map would overlap, bail out */
+		lmb_free_flags(addr, (u64)pages << EFI_PAGE_SHIFT, flags);
+		unmap_sysmem((void *)(uintptr_t)efi_addr);
 		return  EFI_OUT_OF_RESOURCES;
+	}

-	*memory = addr;
+	*memory = efi_addr;

 	return EFI_SUCCESS;
 }
@@ -546,6 +549,8 @@ efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
 	if (status)
 		return EFI_NOT_FOUND;

+	unmap_sysmem((void *)(uintptr_t)memory);
+
 	return ret;
 }

--
2.45.2