linux-kernel - [RFC PATCH 07/14] powerpc/ftrace: Remove dead code

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]

Date:   Thu, 26 Nov 2020 23:38:44 +0530
From:   "Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>
To:     Steven Rostedt <rostedt@...dmis.org>,
        Michael Ellerman <mpe@...erman.id.au>
Cc:     <linux-kernel@...r.kernel.org>, <linuxppc-dev@...ts.ozlabs.org>
Subject: [RFC PATCH 07/14] powerpc/ftrace: Remove dead code

ftrace_plt_tramps[] was intended to speed up skipping plt branches, but
the code wasn't completed. It is also not significantly better than
reading and decoding the instruction. Remove the same.

Signed-off-by: Naveen N. Rao <naveen.n.rao@...ux.vnet.ibm.com>
---
 arch/powerpc/kernel/trace/ftrace.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 42761ebec9f755..4fe5f373172fd2 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -332,7 +332,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	struct ppc_inst op;
 	unsigned long ptr;
 	struct ppc_inst instr;
-	static unsigned long ftrace_plt_tramps[NUM_FTRACE_TRAMPS];
 
 	/* Is this a known long jump tramp? */
 	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
@@ -341,13 +340,6 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 		else if (ftrace_tramps[i] == tramp)
 			return 0;
 
-	/* Is this a known plt tramp? */
-	for (i = 0; i < NUM_FTRACE_TRAMPS; i++)
-		if (!ftrace_plt_tramps[i])
-			break;
-		else if (ftrace_plt_tramps[i] == tramp)
-			return -1;
-
 	/* New trampoline -- read where this goes */
 	if (probe_kernel_read_inst(&op, (void *)tramp)) {
 		pr_debug("Fetching opcode failed.\n");
-- 
2.25.4