linux-kernel - [RFC PATCH tip/master 2/8] kprobes/x86: Fix the description of __copy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <149049874967.5373.17469037610998139025.stgit@devbox>
Date:   Sun, 26 Mar 2017 12:25:59 +0900
From:   Masami Hiramatsu <mhiramat@...nel.org>
To:     linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...hat.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Ananth N Mavinakayanahalli <ananth@...ux.vnet.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@...el.com>,
        "David S . Miller" <davem@...emloft.net>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>, mhiramat@...nel.org
Subject: [RFC PATCH tip/master 2/8] kprobes/x86: Fix the description of __copy_instruction()

Fix the description comment of __copy_instruction() function
since it has already been changed to return the length of
copied instruction.

Signed-off-by: Masami Hiramatsu <mhiramat@...nel.org>
---
 arch/x86/kernel/kprobes/core.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 9eae5a6..81d4dc7 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -350,11 +350,10 @@ static int is_IF_modifier(kprobe_opcode_t *insn)
 }
 
 /*
- * Copy an instruction and adjust the displacement if the instruction
- * uses the %rip-relative addressing mode.
- * If it does, Return the address of the 32-bit displacement word.
- * If not, return null.
- * Only applicable to 64-bit x86.
+ * Copy an instruction with recovering modified instruction by kprobes
+ * and adjust the displacement if the instruction uses the %rip-relative
+ * addressing mode.
+ * This returns the length of copied instruction, or 0 if it has an error.
  */
 int __copy_instruction(u8 *dest, u8 *src)
 {
@@ -376,6 +375,7 @@ int __copy_instruction(u8 *dest, u8 *src)
 	memcpy(dest, insn.kaddr, length);
 
 #ifdef CONFIG_X86_64
+	/* Only x86_64 has RIP relative instructions */
 	if (insn_rip_relative(&insn)) {
 		s64 newdisp;
 		u8 *disp;