[tip:x86/cleanups] x86/dumpstack: Carve out code-dumping into a function

tip-bot for Borislav Petkov
2018-04-26T14:20:15Z

Commit-ID: f0a1d7c11c3ebe2f601b448d13e7fbc3a0364a03
Gitweb: https://git.kernel.org/tip/f0a1d7c11c3ebe2f601b448d13e7fbc3a0364a03
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Tue, 17 Apr 2018 18:11:18 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 26 Apr 2018 16:15:26 +0200

x86/dumpstack: Carve out code-dumping into a function

No functionality change, carve it out into a separate function for later
changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/20180417161124.5294-4-bp@alien8.de

---
arch/x86/kernel/dumpstack.c | 57 ++++++++++++++++++++++++---------------------
1 file changed, 30 insertions(+), 27 deletions(-)

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 579455c2b91e..eb9d6c00a52f 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -70,6 +70,35 @@ static void printk_stack_address(unsigned long address, int reliable,
printk("%s %s%pB\n", log_lvl, reliable ? "" : "? ", (void *)address);
}

+static void show_opcodes(u8 *rip)
+{
+ unsigned int code_prologue = OPCODE_BUFSIZE * 43 / 64;
+ unsigned int code_len = OPCODE_BUFSIZE;
+ unsigned char c;
+ u8 *ip;
+ int i;
+
+ printk(KERN_DEFAULT "Code: ");
+
+ ip = (u8 *)rip - code_prologue;
+ if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
+ /* try starting at IP */
+ ip = (u8 *)rip;
+ code_len = code_len - code_prologue + 1;
+ }
+ for (i = 0; i < code_len; i++, ip++) {
+ if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
+ pr_cont(" Bad RIP value.");
+ break;
+ }
+ if (ip == (u8 *)rip)
+ pr_cont("<%02x> ", c);
+ else
+ pr_cont("%02x ", c);
+ }
+ pr_cont("\n");
+}
+
void show_iret_regs(struct pt_regs *regs)
{
printk(KERN_DEFAULT "RIP: %04x:%pS\n", (int)regs->cs, (void *)regs->ip);
@@ -359,7 +388,6 @@ void die(const char *str, struct pt_regs *regs, long err)
void show_regs(struct pt_regs *regs)
{
bool all = true;
- int i;

show_regs_print_info(KERN_DEFAULT);

@@ -373,32 +401,7 @@ void show_regs(struct pt_regs *regs)
* time of the fault..
*/
if (!user_mode(regs)) {
- unsigned int code_prologue = OPCODE_BUFSIZE * 43 / 64;
- unsigned int code_len = OPCODE_BUFSIZE;
- unsigned char c;
- u8 *ip;
-
show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);
-
- printk(KERN_DEFAULT "Code: ");
-
- ip = (u8 *)regs->ip - code_prologue;
- if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
- /* try starting at IP */
- ip = (u8 *)regs->ip;
- code_len = code_len - code_prologue + 1;
- }
- for (i = 0; i < code_len; i++, ip++) {
- if (ip < (u8 *)PAGE_OFFSET ||
- probe_kernel_address(ip, c)) {
- pr_cont(" Bad RIP value.");
- break;
- }
- if (ip == (u8 *)regs->ip)
- pr_cont("<%02x> ", c);
- else
- pr_cont("%02x ", c);
- }
+ show_opcodes((u8 *)regs->ip);
}
- pr_cont("\n");
}