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| author | Mario Limonciello <mario.limonciello@amd.com> | 2026-07-21 13:17:54 -0500 |
|---|---|---|
| committer | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2026-07-27 14:42:22 +0300 |
| commit | 34d145254ca655ead49d00025981f2f5b200a62f (patch) | |
| tree | 70c8e42106decb5862599bad3c2095bb485a5b4a | |
| parent | 0225c1d637687b03726f00ac65b6def843d2c464 (diff) | |
| download | linux-next-34d145254ca655ead49d00025981f2f5b200a62f.tar.gz linux-next-34d145254ca655ead49d00025981f2f5b200a62f.zip | |
platform/x86/amd/pmc: Only expose stb_read after telemetry buffer is mapped
amd_stb_s2d_init() creates the v2 "stb_read" debugfs node before mapping
the telemetry buffer into dev->stb_virt_addr, leaving a window during probe
where a read faults on a NULL dev->stb_virt_addr in
amd_stb_debugfs_open_v2()/amd_stb_handle_efr().
This becomes trivial to hit once a failed STB init no longer aborts probe
(next patch), which leaves the node registered with a NULL buffer. Create
it only after dev->stb_virt_addr is mapped.
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20260721181756.143084-5-mario.limonciello@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
| -rw-r--r-- | drivers/platform/x86/amd/pmc/mp1_stb.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/platform/x86/amd/pmc/mp1_stb.c b/drivers/platform/x86/amd/pmc/mp1_stb.c index 1ec0e599df7f..8a33e75b71c3 100644 --- a/drivers/platform/x86/amd/pmc/mp1_stb.c +++ b/drivers/platform/x86/amd/pmc/mp1_stb.c @@ -299,10 +299,7 @@ int amd_stb_s2d_init(struct amd_pmc_dev *dev) if (!enable_stb) return 0; - if (amd_is_stb_supported(dev)) { - debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev, - &amd_stb_debugfs_fops_v2); - } else { + if (!amd_is_stb_supported(dev)) { debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev, &amd_stb_debugfs_fops); return 0; @@ -342,8 +339,18 @@ int amd_stb_s2d_init(struct amd_pmc_dev *dev) } dev->stb_virt_addr = devm_ioremap(dev->dev, stb_phys_addr, dev->dram_size); - if (!dev->stb_virt_addr) + if (!dev->stb_virt_addr) { ret = -ENOMEM; + goto out; + } + + /* + * Only expose stb_read once the buffer is mapped; otherwise a read + * faults on a NULL dev->stb_virt_addr, now that a failed STB init no + * longer aborts probe. + */ + debugfs_create_file("stb_read", 0644, dev->dbgfs_dir, dev, + &amd_stb_debugfs_fops_v2); out: /* Restore the default message port for subsequent SMU operations */ |