linux-kernel - [PATCH 2/7] efi/libstub: Use C99-style for loop to traverse handle buffer

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Message-ID: <20241220112214.2598872-11-ardb+git@google.com>
Date: Fri, 20 Dec 2024 12:22:17 +0100
From: Ard Biesheuvel <ardb+git@...gle.com>
To: linux-efi@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, Ard Biesheuvel <ardb@...nel.org>
Subject: [PATCH 2/7] efi/libstub: Use C99-style for loop to traverse handle buffer

From: Ard Biesheuvel <ardb@...nel.org>

Tweak the for_each_efi_handle() macro in order to avoid the need on the
part of the caller to provide a loop counter variable.

Also move efi_get_handle_num() to the callers, so that each occurrence
can be replaced with the actual number returned by the simplified
LocateHandleBuffer API.

Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
---
 drivers/firmware/efi/libstub/efistub.h  | 9 ++++-----
 drivers/firmware/efi/libstub/gop.c      | 3 +--
 drivers/firmware/efi/libstub/pci.c      | 5 ++---
 drivers/firmware/efi/libstub/x86-stub.c | 3 +--
 4 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index d0989e072b2b..c321735eb237 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -123,11 +123,10 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 #define efi_get_handle_num(size)					\
 	((size) / (efi_is_native() ? sizeof(efi_handle_t) : sizeof(u32)))
 
-#define for_each_efi_handle(handle, array, size, i)			\
-	for (i = 0;							\
-	     i < efi_get_handle_num(size) &&				\
-		((handle = efi_get_handle_at((array), i)) || true);	\
-	     i++)
+#define for_each_efi_handle(handle, array, num)				\
+	for (int __i = 0; __i < (num) &&				\
+		((handle = efi_get_handle_at((array), __i)) || true);	\
+	     __i++)
 
 static inline
 void efi_set_u64_split(u64 data, u32 *lo, u32 *hi)
diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index ea5da307d542..8eef63c48288 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -466,11 +466,10 @@ find_gop(efi_guid_t *proto, unsigned long size, void **handles)
 {
 	efi_graphics_output_protocol_t *first_gop;
 	efi_handle_t h;
-	int i;
 
 	first_gop = NULL;
 
-	for_each_efi_handle(h, handles, size, i) {
+	for_each_efi_handle(h, handles, efi_get_handle_num(size)) {
 		efi_status_t status;
 
 		efi_graphics_output_protocol_t *gop;
diff --git a/drivers/firmware/efi/libstub/pci.c b/drivers/firmware/efi/libstub/pci.c
index 99fb25d2bcf5..b0ba372c26c5 100644
--- a/drivers/firmware/efi/libstub/pci.c
+++ b/drivers/firmware/efi/libstub/pci.c
@@ -21,7 +21,6 @@ void efi_pci_disable_bridge_busmaster(void)
 	efi_handle_t handle;
 	efi_status_t status;
 	u16 class, command;
-	int i;
 
 	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL, &pci_proto,
 			     NULL, &pci_handle_size, NULL);
@@ -46,7 +45,7 @@ void efi_pci_disable_bridge_busmaster(void)
 		goto free_handle;
 	}
 
-	for_each_efi_handle(handle, pci_handle, pci_handle_size, i) {
+	for_each_efi_handle(handle, pci_handle, efi_get_handle_num(pci_handle_size)) {
 		efi_pci_io_protocol_t *pci;
 		unsigned long segment_nr, bus_nr, device_nr, func_nr;
 
@@ -82,7 +81,7 @@ void efi_pci_disable_bridge_busmaster(void)
 		efi_bs_call(disconnect_controller, handle, NULL, NULL);
 	}
 
-	for_each_efi_handle(handle, pci_handle, pci_handle_size, i) {
+	for_each_efi_handle(handle, pci_handle, efi_get_handle_num(pci_handle_size)) {
 		efi_pci_io_protocol_t *pci;
 
 		status = efi_bs_call(handle_protocol, handle, &pci_proto,
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 0c51d8307000..71173471faf6 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -124,7 +124,6 @@ static void setup_efi_pci(struct boot_params *params)
 	unsigned long size = 0;
 	struct setup_data *data;
 	efi_handle_t h;
-	int i;
 
 	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 			     &pci_proto, NULL, &size, pci_handle);
@@ -150,7 +149,7 @@ static void setup_efi_pci(struct boot_params *params)
 	while (data && data->next)
 		data = (struct setup_data *)(unsigned long)data->next;
 
-	for_each_efi_handle(h, pci_handle, size, i) {
+	for_each_efi_handle(h, pci_handle, efi_get_handle_num(size)) {
 		efi_pci_io_protocol_t *pci = NULL;
 		struct pci_setup_rom *rom;
 
-- 
2.47.1.613.gc27f4b7a9f-goog