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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/firmware/efi/ovmf-debug-log.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/firmware/efi/ovmf-debug-log.c')
-rw-r--r--drivers/firmware/efi/ovmf-debug-log.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/firmware/efi/ovmf-debug-log.c b/drivers/firmware/efi/ovmf-debug-log.c
new file mode 100644
index 000000000..5b2471ffa
--- /dev/null
+++ b/drivers/firmware/efi/ovmf-debug-log.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+
+#define OVMF_DEBUG_LOG_MAGIC1 0x3167646d666d766f // "ovmfmdg1"
+#define OVMF_DEBUG_LOG_MAGIC2 0x3267646d666d766f // "ovmfmdg2"
+
+struct ovmf_debug_log_header {
+ u64 magic1;
+ u64 magic2;
+ u64 hdr_size;
+ u64 log_size;
+ u64 lock; // edk2 spinlock
+ u64 head_off;
+ u64 tail_off;
+ u64 truncated;
+ u8 fw_version[128];
+};
+
+static struct ovmf_debug_log_header *hdr;
+static u8 *logbuf;
+static u64 logbufsize;
+
+static ssize_t ovmf_log_read(struct file *filp, struct kobject *kobj,
+ const struct bin_attribute *attr, char *buf,
+ loff_t offset, size_t count)
+{
+ u64 start, end;
+
+ start = hdr->head_off + offset;
+ if (hdr->head_off > hdr->tail_off && start >= hdr->log_size)
+ start -= hdr->log_size;
+
+ end = start + count;
+ if (start > hdr->tail_off) {
+ if (end > hdr->log_size)
+ end = hdr->log_size;
+ } else {
+ if (end > hdr->tail_off)
+ end = hdr->tail_off;
+ }
+
+ if (start > logbufsize || end > logbufsize)
+ return 0;
+ if (start >= end)
+ return 0;
+
+ memcpy(buf, logbuf + start, end - start);
+ return end - start;
+}
+
+static struct bin_attribute ovmf_log_bin_attr = {
+ .attr = {
+ .name = "ovmf_debug_log",
+ .mode = 0444,
+ },
+ .read = ovmf_log_read,
+};
+
+int __init ovmf_log_probe(unsigned long ovmf_debug_log_table)
+{
+ int ret = -EINVAL;
+ u64 size;
+
+ /* map + verify header */
+ hdr = memremap(ovmf_debug_log_table, sizeof(*hdr), MEMREMAP_WB);
+ if (!hdr) {
+ pr_err("OVMF debug log: header map failed\n");
+ return -EINVAL;
+ }
+
+ if (hdr->magic1 != OVMF_DEBUG_LOG_MAGIC1 ||
+ hdr->magic2 != OVMF_DEBUG_LOG_MAGIC2) {
+ printk(KERN_ERR "OVMF debug log: magic mismatch\n");
+ goto err_unmap;
+ }
+
+ size = hdr->hdr_size + hdr->log_size;
+ pr_info("OVMF debug log: firmware version: \"%s\"\n", hdr->fw_version);
+ pr_info("OVMF debug log: buffer size: %lluk\n", size / 1024);
+
+ /* map complete log buffer */
+ memunmap(hdr);
+ hdr = memremap(ovmf_debug_log_table, size, MEMREMAP_WB);
+ if (!hdr) {
+ pr_err("OVMF debug log: buffer map failed\n");
+ return -EINVAL;
+ }
+ logbuf = (void *)hdr + hdr->hdr_size;
+ logbufsize = hdr->log_size;
+
+ ovmf_log_bin_attr.size = size;
+ ret = sysfs_create_bin_file(efi_kobj, &ovmf_log_bin_attr);
+ if (ret != 0) {
+ pr_err("OVMF debug log: sysfs register failed\n");
+ goto err_unmap;
+ }
+
+ return 0;
+
+err_unmap:
+ memunmap(hdr);
+ return ret;
+}