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From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: barebox@lists.infradead.org
Cc: Ahmad Fatoum <a.fatoum@pengutronix.de>
Subject: [PATCH 089/112] efi: devicepath: implement device_path_to_str_buf variant
Date: Wed,  3 Jan 2024 19:12:49 +0100	[thread overview]
Message-ID: <20240103181312.409668-90-a.fatoum@pengutronix.de> (raw)
In-Reply-To: <20240103181312.409668-1-a.fatoum@pengutronix.de>

Existing device_path_to_str() formats a buffer once to determines the amount
of space necessary and then allocates it and formats it again.

To make this functionality available as printf format specifier, we need
a variant that doesn't allocate memory and that's preferably single
pass, which we add here.

No functional change for users of device_path_to_str().

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 efi/devicepath.c | 71 +++++++++++++++++++++++++++++++++++-------------
 include/efi.h    |  1 +
 2 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/efi/devicepath.c b/efi/devicepath.c
index d562bf482955..0c2fc4d86927 100644
--- a/efi/devicepath.c
+++ b/efi/devicepath.c
@@ -6,11 +6,13 @@
 #include <malloc.h>
 #include <string.h>
 #include <wchar.h>
+#include <linux/overflow.h>
 #include <efi/device-path.h>
 
 struct string {
 	char *str;
-	int len;
+	unsigned allocated;
+	unsigned used;
 };
 
 char *cprintf(struct string *str, const char *fmt, ...)
@@ -18,17 +20,22 @@ char *cprintf(struct string *str, const char *fmt, ...)
 
 char *cprintf(struct string *str, const char *fmt, ...)
 {
+	void *buf = str->str;
+	unsigned bufsize = 0;
 	va_list args;
 	int len;
 
+	if (str->str) {
+		buf += str->used;
+		if (check_sub_overflow(str->allocated, str->used, &bufsize))
+			bufsize = 0;
+	}
+
 	va_start(args, fmt);
-	if (str->str)
-		len = vsprintf(str->str + str->len, fmt, args);
-	else
-		len = vsnprintf(NULL, 0, fmt, args);
+	len = vsnprintf(buf, bufsize, fmt, args);
 	va_end(args);
 
-	str->len += len;
+	str->used += len;
 
 	return NULL;
 }
@@ -717,8 +724,8 @@ struct {
 	0, 0, NULL}
 };
 
-static int __device_path_to_str(struct string *str,
-				const struct efi_device_path *dev_path)
+static void __device_path_to_str(struct string *str,
+				 const struct efi_device_path *dev_path)
 {
 	const struct efi_device_path *dev_path_node;
 	void (*dump_node) (struct string *, const void *);
@@ -743,32 +750,58 @@ static int __device_path_to_str(struct string *str,
 		if (!dump_node)
 			dump_node = dev_path_node_unknown;
 
-		if (str->len && dump_node != dev_path_end_instance)
+		if (str->used && dump_node != dev_path_end_instance)
 			cprintf(str, "/");
 
 		dump_node(str, dev_path_node);
 
 		dev_path_node = next_device_path_node(dev_path_node);
 	}
-
-	return 0;
 }
 
+/**
+ * device_path_to_str_buf() - formats a device path into a preallocated buffer
+ *
+ * @dev_path:	The EFI device path to format
+ * @buf:	The buffer to format into or optionally NULL if @len is zero
+ * @len:	The number of bytes that may be written into @buf
+ * Return:	total number of bytes that are required to store the formatted
+ *		result, excluding the terminating NUL byte, which is always
+ *		written.
+ */
+size_t device_path_to_str_buf(const struct efi_device_path *dev_path,
+			      char *buf, size_t len)
+{
+	struct string str = {
+		.str = buf,
+		.allocated = len,
+	};
+
+	__device_path_to_str(&str, dev_path);
+
+	return str.used;
+}
+
+/**
+ * device_path_to_str() - formats a device path into a newly allocated buffer
+ *
+ * @dev_path:	The EFI device path to format
+ * Return:	A pointer to the nul-terminated formatted device path.
+ */
 char *device_path_to_str(const struct efi_device_path *dev_path)
 {
-	struct string str = {};
+	void *buf;
+	size_t size;
 
-	__device_path_to_str(&str, dev_path);
+	size = device_path_to_str_buf(dev_path, NULL, 0);
 
-	str.str = malloc(str.len + 1);
-	if (!str.str)
+	buf = malloc(size + 1);
+	if (!buf)
 		return NULL;
 
-	str.len = 0;
+	device_path_to_str_buf(dev_path, buf, size + 1);
 
-	__device_path_to_str(&str, dev_path);
-
-	return str.str;
+	return buf;
 }
 
 u8 device_path_to_type(const struct efi_device_path *dev_path)
diff --git a/include/efi.h b/include/efi.h
index 6795dc414c3c..45e4080fac08 100644
--- a/include/efi.h
+++ b/include/efi.h
@@ -880,6 +880,7 @@ struct efi_simple_text_input_protocol {
 
 const struct efi_device_path *device_path_from_handle(efi_handle_t handle);
 char *device_path_to_str(const struct efi_device_path *dev_path);
+size_t device_path_to_str_buf(const struct efi_device_path *dev_path, char buf[], size_t size);
 u8 device_path_to_type(const struct efi_device_path *dev_path);
 u8 device_path_to_subtype(const struct efi_device_path *dev_path);
 char *device_path_to_partuuid(const struct efi_device_path *dev_path);
-- 
2.39.2




  parent reply	other threads:[~2024-01-03 18:32 UTC|newest]

Thread overview: 134+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-03 18:11 [PATCH 000/112] efi: prepare for ARM64 EFI loader support Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 001/112] string: implement strcmp_ptr and streq_ptr helpers Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 002/112] commands: efiexit: flush console and shutdown barebox Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 003/112] treewide: add errno_set helper for returning positive error code in errno Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 004/112] vsprintf: guard against NULL in UUID %pU Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 005/112] common: add option to poweroff system on failure Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 006/112] boot: print error code when booting fails Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 007/112] common: efi: move directory to top-level Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 008/112] efi: payload: rename CONFIG_EFI_BOOTUP to CONFIG_EFI_PAYLOAD Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 009/112] efi: payload: image: return actual read_file() error Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 010/112] of: don't report failure to of_read_file twice Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 011/112] efi: payload: make missing state reporting less verbose Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 012/112] libfile: factor out read_file_into_buf helper Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 013/112] efi: payload: image: allocate image via loader if it exceeds malloc area Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 014/112] efi: payload: image: use assigned barebox loader type on x86 Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 015/112] efi: payload: iomem: adjust types to avoid casting Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 016/112] commands: kallsyms: add command-line interface Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 017/112] block: define BLOCKSIZE globally in block.h Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 018/112] cdev: implement setter/getter for cdev device node Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 019/112] block: virtio: assign virtio-mmio device tree node to cdevs Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 020/112] commands: stat: print DT node for cdevs if available Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 021/112] partitions: have parsers record bootable bits Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 022/112] commands: stat: display bootable partition table bit info Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 023/112] block: record block device type Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 024/112] include: add definitions for UAPI discoverable partitions spec Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 025/112] efi: payload: restrict 8250 UART at I/O port 0x3f8 registration to x86 Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 026/112] fs: fix unreaddir, so readdir returns unread dirent first Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 027/112] fs: turn creat into static inline helper Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 028/112] fs: drop unused LOOKUP_ flags Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 029/112] fs: opendir: reference mount point until closedir is called Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 030/112] fs: factor out opendir iteration Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 031/112] fs: implement fdopendir and rewinddir Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 032/112] fs: remove unused member from struct nameidata Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 033/112] fs: always check path_init for errors Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 034/112] fs: set current working dir directly when mounting root Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 035/112] fs: implement openat and friends Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 036/112] fs: implement O_PATH Ahmad Fatoum
2024-01-05 11:22   ` Sascha Hauer
2024-01-05 11:26     ` Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 037/112] fs: support different root directories Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 038/112] fs: implement O_CHROOT Ahmad Fatoum
2024-01-03 18:11 ` [PATCH 039/112] commands: introduce new findmnt command Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 040/112] fs: initialize struct nameidata::last Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 041/112] fs: support opening / Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 042/112] test: self: add dirfd tests Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 043/112] commands: stat: add option for statat Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 044/112] efi: payload: lower command line options print from error to info Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 045/112] efi: payload: init: warn if /boot FS is unknown Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 046/112] commands: time: refactor into new strjoin Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 047/112] string: reduce strjoin runtime, drop trailing separator Ahmad Fatoum
2024-01-08  7:11   ` Sascha Hauer
2024-01-08  7:18     ` Ahmad Fatoum
2024-01-08  7:43       ` Sascha Hauer
2024-01-03 18:12 ` [PATCH 048/112] test: self: add strjoin tests Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 049/112] filetype: have cdev_detect_type take a cdev Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 050/112] ARM: mmu-early: gracefully handle already enabled MMU Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 051/112] efi: don't hide structs, enums or unions behind _t Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 052/112] efi: make headers self-contained Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 053/112] efi: unify whitespace for GUIDs Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 054/112] efi: efi-guid: add more GUIDs Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 055/112] ARM64: cpu: setupc: rewrite to be fully PIC Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 056/112] ARM64: runtime-offset: make get_runtime_offset " Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 057/112] pbl: introduce CONFIG_PBL_FULLY_PIC Ahmad Fatoum
2024-01-08  7:47   ` Sascha Hauer
2024-01-22 19:15     ` Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 058/112] efi: payload: fix ARM build Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 059/112] efi: payload: init: restrict barebox mem to first 1G only on x86 Ahmad Fatoum
2024-01-03 18:58   ` Michael Olbrich
2024-01-04 11:17     ` Ahmad Fatoum
2024-01-04 18:10       ` Michael Olbrich
2024-01-05  9:14         ` Ahmad Fatoum
2024-01-05  9:31           ` Michael Olbrich
2024-01-05 10:41             ` Ahmad Fatoum
2024-01-05 14:58               ` Michael Olbrich
2024-01-08  7:22                 ` Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 060/112] ARM: pbl: add 64K segment alignment for PE/COFF Ahmad Fatoum
2024-01-08  8:05   ` Sascha Hauer
2024-01-22 19:18     ` Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 061/112] efi: add efi_is_loader/efi_is_payload helpers Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 062/112] efi: payload: suppress EFI payload initcalls when not EFI-loaded Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 063/112] ARM: make board data definitions accessible to other architectures Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 064/112] boarddata: add barebox_boarddata_is_machine helper Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 065/112] common: add PE/COFF loader Ahmad Fatoum
2024-01-08  8:37   ` Sascha Hauer
2024-03-04 17:09     ` Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 066/112] efi: use efi_handle_t where appropriate Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 067/112] efi: block: move definitions into header file Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 068/112] efi: define efi_handle_t as opaque pointer Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 069/112] efi: constify guid_t in API Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 070/112] efi: rename efi_simple_input_interface to efi_simple_text_input_protocol Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 071/112] efi: add EFI_WARN constants Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 072/112] efi-stdio: fix wait_for_event argument Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 073/112] efi-stdio: wait for extended input key event when using extended input Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 074/112] efi: flesh out EFI definitions in header Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 075/112] efi: add efi_driver_binding_protocol Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 076/112] efi: improve usability of EFI_PAGE_* macros Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 077/112] fs: efi: move definitions into header Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 078/112] efi: fs: flesh out file system definitions Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 079/112] efi: stdio: fix efi_register_keystroke_notify prototype Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 080/112] video: mark EFI_GOP driver x86-only for now Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 081/112] filetype: add new file types for EFI-enabled Linux images Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 082/112] efi: payload: register handler for EFI-stubbed ARM64 kernel Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 083/112] efi: payload: factor C efi_main into dedicated file Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 084/112] efi: payload: early-mem: simplify error message reporting Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 085/112] efi: payload: early-mem: use EFI_PAGE_SIZE instead of PAGE_SIZE Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 086/112] ARM64: add optional EFI stub Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 087/112] efi: devicepath: improve const safety Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 088/112] efi: refactor device_path_to_partuuid for code reuse Ahmad Fatoum
2024-01-03 18:12 ` Ahmad Fatoum [this message]
2024-01-03 18:12 ` [PATCH 090/112] vsprintf: add %pD for printing EFI device path Ahmad Fatoum
2024-01-08  9:01   ` Sascha Hauer
2024-03-04 17:26     ` Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 091/112] lib: string: import Linux strreplace helper Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 092/112] efi: payload: dynamically determine bootloader file name Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 093/112] efi: payload: iomem: register later Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 094/112] efi: payload: protect against buggy EFI implementations Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 095/112] efi: payload: don't require efi_loaded_image->parent_handle for bootsource detection Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 096/112] commands: add cpuinfo -s option for stacktrace Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 097/112] efi: devicepath: align MemoryMapped name with spec Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 098/112] efi: devicepath: pretty print BBS BEV DeviceType Ahmad Fatoum
2024-01-03 18:12 ` [PATCH 099/112] efi: devicepath: format GUIDs as little endian Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 100/112] efi: devicepath: move END device node definitions into header Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 101/112] efi: devicepath: drop underscores in hex constants Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 102/112] efi: devicepath: namespace definitions Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 103/112] efi: devicepath: use flexible array members for trailing strings Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 104/112] efi: devicepath: drop unused macro Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 105/112] efi: devicepath: let compiler worry about unaligned unpacking Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 106/112] efi: devicepath: correct formatting of BBS Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 107/112] commands: provide efi_handle_dump in both payload and loader Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 108/112] lib: uuid: implement uuid/guid_parse Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 109/112] commands: efi_handle_dump: prepare for supporting EFI loader Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 110/112] commands: efi_handle_dump: print loaded image devpath Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 111/112] commands: efi_handle_dump: use guid_parse instead of open-coding Ahmad Fatoum
2024-01-03 18:13 ` [PATCH 112/112] commands: efi_handle_dump: don't ignore failure to parse GUID Ahmad Fatoum

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