From 2223cbf7de8d32bfde1e00502cb02c7b13184435 Mon Sep 17 00:00:00 2001 From: Alex Feinman Date: Wed, 20 Feb 2019 11:49:51 -0800 Subject: intelvbttool: Add support for reading vbt from sysfs VBT on Intel(R) systems is available via sysfs as /sys/kernel/debug/dri/0/i915_vbt However the size of this file reads as 0 causing intelvbttool to fail. This patch implements incremental reads with realloc for such cases or whenever the file size is not available (e.g. reading from stdin). After this patch is applied, intelvbttool can be used as follows: sudo intelvbttool -f /sys/kernel/debug/dri/0/i915_vbt -d Change-Id: I5d17095a5747550b7115a54a7619b7294a846196 Signed-off-by: Alex Feinman Reviewed-on: https://review.coreboot.org/c/31531 Tested-by: build bot (Jenkins) Reviewed-by: Nico Huber --- util/intelvbttool/intelvbttool.c | 39 +++++++++++++++++---------------------- 1 file changed, 17 insertions(+), 22 deletions(-) (limited to 'util/intelvbttool') diff --git a/util/intelvbttool/intelvbttool.c b/util/intelvbttool/intelvbttool.c index 1444129b50..f8e4bda0f4 100644 --- a/util/intelvbttool/intelvbttool.c +++ b/util/intelvbttool/intelvbttool.c @@ -29,6 +29,7 @@ typedef uint8_t u8; typedef uint16_t u16; typedef uint32_t u32; +#define DEF_ALLOC 1024 typedef struct { u16 signature; @@ -380,39 +381,33 @@ static struct fileobject *malloc_fo_sub(const struct fileobject *old, static struct fileobject *read_file(const char *filename) { FILE *fd = fopen(filename, "rb"); + off_t read_size = DEF_ALLOC; if (!fd) { printerr("%s open failed: %s\n", filename, strerror(errno)); return NULL; } - if (fseek(fd, 0, SEEK_END)) { - printerr("%s seek failed: %s\n", filename, strerror(errno)); - fclose(fd); - return NULL; - } - - const off_t size = ftell(fd); - if (size < 0 || size > SIZE_MAX) { - printerr("%s tell failed: %s\n", filename, strerror(errno)); - fclose(fd); - return NULL; - } - - if (fseek(fd, 0, SEEK_SET)) { - printerr("%s seek failed: %s\n", filename, strerror(errno)); - fclose(fd); - return NULL; - } - - struct fileobject *fo = malloc_fo(size); + struct fileobject *fo = malloc_fo(read_size); if (!fo) { printerr("malloc failed\n"); fclose(fd); return NULL; } - if (fread(fo->data, 1, size, fd) != size) { + off_t total_bytes_read = 0, bytes_read; + while ((bytes_read = fread(fo->data + total_bytes_read, 1, read_size, fd)) > 0) { + total_bytes_read += bytes_read; + struct fileobject *newfo = remalloc_fo(fo, fo->size + read_size); + if (!newfo) { + fclose(fd); + free_fo(fo); + return NULL; + } + fo = newfo; + } + + if (!total_bytes_read) { fclose(fd); free_fo(fo); return NULL; @@ -424,7 +419,7 @@ static struct fileobject *read_file(const char *filename) return NULL; } - fo->size = size; + fo->size = total_bytes_read; return fo; } -- cgit v1.2.3