Re: [PATCH v2 01/59] x86/paravirt: Ensure proper alignment

From: Juergen Gross
Date: Fri Sep 02 2022 - 12:11:39 EST


On 02.09.22 15:06, Peter Zijlstra wrote:
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

The entries in the .parainstr sections are 8 byte aligned and the
corresponding C struct makes the array offset 16 bytes.

Though the pushed entries are only using 12 bytes. .parainstr_end is
therefore 4 bytes short.

That works by chance because it's only used in a loop:

for (p = start; p < end; p++)

But this falls flat when calculating the number of elements:

n = end - start

That's obviously off by one.

Ensure that the gap is filled and the last entry is occupying 16 bytes.

Cc: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Juergen

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