Andrew Cooper 3bc5887b0a x86/fred: Correct speculative safety in fred_extint() ...

[ Upstream commit aa280a08e7 ]

array_index_nospec() is no use if the result gets spilled to the stack, as
it makes the believed safe-under-speculation value subject to memory
predictions.

For all practical purposes, this means array_index_nospec() must be used in
the expression that accesses the array.

As the code currently stands, it's the wrong side of irqentry_enter(), and
'index' is put into %ebp across the function call.

Remove the index variable and reposition array_index_nospec(), so it's
calculated immediately before the array access.

Fixes: 14619d912b ("x86/fred: FRED entry/exit and dispatch code")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260106131504.679932-1-andrew.cooper3@citrix.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

2026-03-13 17:20:17 +01:00

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syscalls

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vdso

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vsyscall

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calling.h

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common.c

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entry_32.S

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entry_64_compat.S

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entry_64_fred.S

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entry_64.S

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entry_fred.c

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entry.S

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Makefile

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syscall_32.c

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syscall_64.c

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syscall_x32.c

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thunk.S

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