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| author | Juergen Gross <jgross@suse.com> | 2023-05-02 14:09:29 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-06-01 15:04:33 +0200 |
| commit | 973df1942068c0cc72244ce7dce5e5aeca03ad5f (patch) | |
| tree | 3fc6230c4acde5b2c7ede986d865766d2a765b1f /arch/x86/kernel | |
| parent | x86/mtrr: Use new cache_map in mtrr_type_lookup() (diff) | |
| download | linux-973df1942068c0cc72244ce7dce5e5aeca03ad5f.tar.xz linux-973df1942068c0cc72244ce7dce5e5aeca03ad5f.zip | |
x86/mtrr: Don't let mtrr_type_lookup() return MTRR_TYPE_INVALID
mtrr_type_lookup() should always return a valid memory type. In case
there is no information available, it should return the default UC.
This will remove the last case where mtrr_type_lookup() can return
MTRR_TYPE_INVALID, so adjust the comment in include/uapi/asm/mtrr.h.
Note that removing the MTRR_TYPE_INVALID #define from that header
could break user code, so it has to stay.
At the same time the mtrr_type_lookup() stub for the !CONFIG_MTRR
case should set uniform to 1, as if the memory range would be
covered by no MTRR at all.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-15-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 4443e71084b8..f6b426d8be4f 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -508,13 +508,13 @@ u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform) if (!mtrr_state_set) { /* Uniformity is unknown. */ *uniform = 0; - return MTRR_TYPE_INVALID; + return MTRR_TYPE_UNCACHABLE; } *uniform = 1; if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED)) - return MTRR_TYPE_INVALID; + return MTRR_TYPE_UNCACHABLE; for (i = 0; i < cache_map_n && start < end; i++) { /* Region after current map entry? -> continue with next one. */ |