From: Mikel Rychliski mikel@mikelr.com
[ Upstream commit 72e0ef0e5f067fd991f702f0b2635d911d0cf208 ]
On some EFI systems, the video BIOS is provided by the EFI firmware. The boot stub code stores the physical address of the ROM image in pdev->rom. Currently we attempt to access this pointer using phys_to_virt(), which doesn't work with CONFIG_HIGHMEM.
On these systems, attempting to load the radeon module on a x86_32 kernel can result in the following:
BUG: unable to handle page fault for address: 3e8ed03c #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 317 Comm: systemd-udevd Not tainted 5.6.0-rc3-next-20200228 #2 Hardware name: Apple Computer, Inc. MacPro1,1/Mac-F4208DC8, BIOS MP11.88Z.005C.B08.0707021221 07/02/07 EIP: radeon_get_bios+0x5ed/0xe50 [radeon] Code: 00 00 84 c0 0f 85 12 fd ff ff c7 87 64 01 00 00 00 00 00 00 8b 47 08 8b 55 b0 e8 1e 83 e1 d6 85 c0 74 1a 8b 55 c0 85 d2 74 13 <80> 38 55 75 0e 80 78 01 aa 0f 84 a4 03 00 00 8d 74 26 00 68 dc 06 EAX: 3e8ed03c EBX: 00000000 ECX: 3e8ed03c EDX: 00010000 ESI: 00040000 EDI: eec04000 EBP: eef3fc60 ESP: eef3fbe0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206 CR0: 80050033 CR2: 3e8ed03c CR3: 2ec77000 CR4: 000006d0 Call Trace: r520_init+0x26/0x240 [radeon] radeon_device_init+0x533/0xa50 [radeon] radeon_driver_load_kms+0x80/0x220 [radeon] drm_dev_register+0xa7/0x180 [drm] radeon_pci_probe+0x10f/0x1a0 [radeon] pci_device_probe+0xd4/0x140
Fix the issue by updating all drivers which can access a platform provided ROM. Instead of calling the helper function pci_platform_rom() which uses phys_to_virt(), call ioremap() directly on the pdev->rom.
radeon_read_platform_bios() previously directly accessed an __iomem pointer. Avoid this by calling memcpy_fromio() instead of kmemdup().
pci_platform_rom() now has no remaining callers, so remove it.
Link: https://lore.kernel.org/r/20200319021623.5426-1-mikel@mikelr.com Signed-off-by: Mikel Rychliski mikel@mikelr.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Acked-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 31 +++++++++++-------- .../drm/nouveau/nvkm/subdev/bios/shadowpci.c | 17 ++++++++-- drivers/gpu/drm/radeon/radeon_bios.c | 30 +++++++++++------- drivers/pci/rom.c | 17 ---------- include/linux/pci.h | 1 - 5 files changed, 52 insertions(+), 44 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c index 50dff69a0f6e3..b1172d93c99c3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c @@ -192,30 +192,35 @@ static bool amdgpu_read_bios_from_rom(struct amdgpu_device *adev)
static bool amdgpu_read_platform_bios(struct amdgpu_device *adev) { - uint8_t __iomem *bios; - size_t size; + phys_addr_t rom = adev->pdev->rom; + size_t romlen = adev->pdev->romlen; + void __iomem *bios;
adev->bios = NULL;
- bios = pci_platform_rom(adev->pdev, &size); - if (!bios) { + if (!rom || romlen == 0) return false; - }
- adev->bios = kzalloc(size, GFP_KERNEL); - if (adev->bios == NULL) + adev->bios = kzalloc(romlen, GFP_KERNEL); + if (!adev->bios) return false;
- memcpy_fromio(adev->bios, bios, size); + bios = ioremap(rom, romlen); + if (!bios) + goto free_bios;
- if (!check_atom_bios(adev->bios, size)) { - kfree(adev->bios); - return false; - } + memcpy_fromio(adev->bios, bios, romlen); + iounmap(bios);
- adev->bios_size = size; + if (!check_atom_bios(adev->bios, romlen)) + goto free_bios; + + adev->bios_size = romlen;
return true; +free_bios: + kfree(adev->bios); + return false; }
#ifdef CONFIG_ACPI diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c index 9b91da09dc5f8..8d9812a51ef63 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c @@ -101,9 +101,13 @@ platform_init(struct nvkm_bios *bios, const char *name) else return ERR_PTR(-ENODEV);
+ if (!pdev->rom || pdev->romlen == 0) + return ERR_PTR(-ENODEV); + if ((priv = kmalloc(sizeof(*priv), GFP_KERNEL))) { + priv->size = pdev->romlen; if (ret = -ENODEV, - (priv->rom = pci_platform_rom(pdev, &priv->size))) + (priv->rom = ioremap(pdev->rom, pdev->romlen))) return priv; kfree(priv); } @@ -111,11 +115,20 @@ platform_init(struct nvkm_bios *bios, const char *name) return ERR_PTR(ret); }
+static void +platform_fini(void *data) +{ + struct priv *priv = data; + + iounmap(priv->rom); + kfree(priv); +} + const struct nvbios_source nvbios_platform = { .name = "PLATFORM", .init = platform_init, - .fini = (void(*)(void *))kfree, + .fini = platform_fini, .read = pcirom_read, .rw = true, }; diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c index c42f73fad3e31..bb29cf02974d1 100644 --- a/drivers/gpu/drm/radeon/radeon_bios.c +++ b/drivers/gpu/drm/radeon/radeon_bios.c @@ -108,25 +108,33 @@ static bool radeon_read_bios(struct radeon_device *rdev)
static bool radeon_read_platform_bios(struct radeon_device *rdev) { - uint8_t __iomem *bios; - size_t size; + phys_addr_t rom = rdev->pdev->rom; + size_t romlen = rdev->pdev->romlen; + void __iomem *bios;
rdev->bios = NULL;
- bios = pci_platform_rom(rdev->pdev, &size); - if (!bios) { + if (!rom || romlen == 0) return false; - }
- if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) { + rdev->bios = kzalloc(romlen, GFP_KERNEL); + if (!rdev->bios) return false; - } - rdev->bios = kmemdup(bios, size, GFP_KERNEL); - if (rdev->bios == NULL) { - return false; - } + + bios = ioremap(rom, romlen); + if (!bios) + goto free_bios; + + memcpy_fromio(rdev->bios, bios, romlen); + iounmap(bios); + + if (rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) + goto free_bios;
return true; +free_bios: + kfree(rdev->bios); + return false; }
#ifdef CONFIG_ACPI diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c index 137bf0cee897c..8fc9a4e911e3a 100644 --- a/drivers/pci/rom.c +++ b/drivers/pci/rom.c @@ -195,20 +195,3 @@ void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom) pci_disable_rom(pdev); } EXPORT_SYMBOL(pci_unmap_rom); - -/** - * pci_platform_rom - provides a pointer to any ROM image provided by the - * platform - * @pdev: pointer to pci device struct - * @size: pointer to receive size of pci window over ROM - */ -void __iomem *pci_platform_rom(struct pci_dev *pdev, size_t *size) -{ - if (pdev->rom && pdev->romlen) { - *size = pdev->romlen; - return phys_to_virt((phys_addr_t)pdev->rom); - } - - return NULL; -} -EXPORT_SYMBOL(pci_platform_rom); diff --git a/include/linux/pci.h b/include/linux/pci.h index 3840a541a9de5..7268dcf1f23e9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1214,7 +1214,6 @@ int pci_enable_rom(struct pci_dev *pdev); void pci_disable_rom(struct pci_dev *pdev); void __iomem __must_check *pci_map_rom(struct pci_dev *pdev, size_t *size); void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom); -void __iomem __must_check *pci_platform_rom(struct pci_dev *pdev, size_t *size);
/* Power management related routines */ int pci_save_state(struct pci_dev *dev);