| Date | Fri, 02 Sep 2022 15:06:26 +0200 | From | Peter Zijlstra <> | Subject | [PATCH v2 01/59] x86/paravirt: Ensure proper alignment |
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From: Thomas Gleixner <tglx@linutronix.de>
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@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- arch/x86/include/asm/paravirt.h | 1 + arch/x86/include/asm/paravirt_types.h | 1 + 2 files changed, 2 insertions(+)
--- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -743,6 +743,7 @@ extern void default_banner(void); word 771b; \ .byte ptype; \ .byte 772b-771b; \ + _ASM_ALIGN; \ .popsection --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -294,6 +294,7 @@ extern struct paravirt_patch_template pv " .byte " type "\n" \ " .byte 772b-771b\n" \ " .short " clobber "\n" \ + _ASM_ALIGN "\n" \ ".popsection\n" /* Generate patchable code, with the default asm parameters. */
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