[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20220915111142.992398801@infradead.org>
Date: Thu, 15 Sep 2022 13:10:40 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: linux-kernel@...r.kernel.org, peterz@...radead.org, x86@...nel.org,
Linus Torvalds <torvalds@...ux-foundation.org>,
Tim Chen <tim.c.chen@...ux.intel.com>,
Josh Poimboeuf <jpoimboe@...nel.org>,
Andrew Cooper <Andrew.Cooper3@...rix.com>,
Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
Johannes Wikner <kwikner@...z.ch>,
Alyssa Milburn <alyssa.milburn@...ux.intel.com>,
Jann Horn <jannh@...gle.com>, "H.J. Lu" <hjl.tools@...il.com>,
Joao Moreira <joao.moreira@...el.com>,
Joseph Nuzman <joseph.nuzman@...el.com>,
Steven Rostedt <rostedt@...dmis.org>,
Juergen Gross <jgross@...e.com>,
Masami Hiramatsu <mhiramat@...nel.org>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
K Prateek Nayak <kprateek.nayak@....com>,
Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH v3 01/59] x86/paravirt: Ensure proper alignment
From: Thomas Gleixner <tglx@...utronix.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.
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Juergen Gross <jgross@...e.com>
---
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. */
Powered by blists - more mailing lists