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| author | David Herrmann <dh.herrmann@gmail.com> | 2016-11-15 15:01:57 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-11-16 11:38:22 +0300 |
| commit | 9164b4ceb7b492a77c7fe770a4b9d1375c9cd45a (patch) | |
| tree | b4a665157bc8148a14bfd148a5aeaf4f70b7f90e /arch/x86/kernel/sysfb_simplefb.c | |
| parent | 81bcfe5e48f9b8c42cf547f1c74c7f60c44c34c8 (diff) | |
| download | linux-9164b4ceb7b492a77c7fe770a4b9d1375c9cd45a.tar.xz | |
x86/sysfb: Add support for 64bit EFI lfb_base
The screen_info object was extended to support 64-bit lfb_base addresses
in:
ae2ee627dc87 ("efifb: Add support for 64-bit frame buffer addresses")
However, the x86 simple-framebuffer setup code never made use of it. Fix
it to properly assemble and verify the lfb_base before advertising
simple-framebuffer devices.
In particular, this means if VIDEO_CAPABILITY_64BIT_BASE is set, the
screen_info->ext_lfb_base field will contain the upper 32bit of the
actual lfb_base. Make sure the address is not 0 (i.e., unset), as well as
does not overflow the physical address type.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Gundersen <teg@jklm.no>
Link: http://lkml.kernel.org/r/20161115120158.15388-2-dh.herrmann@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/sysfb_simplefb.c')
| -rw-r--r-- | arch/x86/kernel/sysfb_simplefb.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c index 764a29f84de7..35b86415871f 100644 --- a/arch/x86/kernel/sysfb_simplefb.c +++ b/arch/x86/kernel/sysfb_simplefb.c @@ -67,6 +67,20 @@ __init int create_simplefb(const struct screen_info *si, struct platform_device *pd; struct resource res; unsigned long len; + u64 base; + + /* + * If the 64BIT_BASE capability is set, ext_lfb_base will contain the + * upper half of the base address. Assemble the address, then make sure + * it is valid and we can actually access it. + */ + base = si->lfb_base; + if (si->capabilities & VIDEO_CAPABILITY_64BIT_BASE) + base |= (u64)si->ext_lfb_base << 32; + if (!base || (u64)(resource_size_t)base != base) { + printk(KERN_DEBUG "sysfb: inaccessible VRAM base\n"); + return -EINVAL; + } /* don't use lfb_size as it may contain the whole VMEM instead of only * the part that is occupied by the framebuffer */ @@ -81,8 +95,8 @@ __init int create_simplefb(const struct screen_info *si, memset(&res, 0, sizeof(res)); res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; res.name = simplefb_resname; - res.start = si->lfb_base; - res.end = si->lfb_base + len - 1; + res.start = base; + res.end = res.start + len - 1; if (res.end <= res.start) return -EINVAL; |