Commit-ID: c1c355ce14c037666fbcb9453d9067c86bbdda5c Gitweb: http://git.kernel.org/tip/c1c355ce14c037666fbcb9453d9067c86bbdda5c Author: Josh Poimboeuf <[email protected]> AuthorDate: Thu, 21 Jan 2016 16:49:28 -0600 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 24 Feb 2016 08:35:44 +0100
x86/kprobes: Get rid of kretprobe_trampoline_holder() The kretprobe_trampoline_holder() wrapper around kretprobe_trampoline() isn't used anywhere and adds some unnecessary frame pointer instructions which never execute. Instead, just make kretprobe_trampoline() a proper ELF function. Signed-off-by: Josh Poimboeuf <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Anil S Keshavamurthy <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Bernd Petrovitsch <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Chris J Arges <[email protected]> Cc: David S. Miller <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michal Marek <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Pedro Alves <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/92d921b102fb865a7c254cfde9e4a0a72b9a781e.1453405861.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/kprobes/core.c | 57 +++++++++++++++++++++--------------------- 1 file changed, 28 insertions(+), 29 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 1deffe6..5b187df 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -671,38 +671,37 @@ NOKPROBE_SYMBOL(kprobe_int3_handler); * When a retprobed function returns, this code saves registers and * calls trampoline_handler() runs, which calls the kretprobe's handler. */ -static void __used kretprobe_trampoline_holder(void) -{ - asm volatile ( - ".global kretprobe_trampoline\n" - "kretprobe_trampoline: \n" +asm( + ".global kretprobe_trampoline\n" + ".type kretprobe_trampoline, @function\n" + "kretprobe_trampoline:\n" #ifdef CONFIG_X86_64 - /* We don't bother saving the ss register */ - " pushq %rsp\n" - " pushfq\n" - SAVE_REGS_STRING - " movq %rsp, %rdi\n" - " call trampoline_handler\n" - /* Replace saved sp with true return address. */ - " movq %rax, 152(%rsp)\n" - RESTORE_REGS_STRING - " popfq\n" + /* We don't bother saving the ss register */ + " pushq %rsp\n" + " pushfq\n" + SAVE_REGS_STRING + " movq %rsp, %rdi\n" + " call trampoline_handler\n" + /* Replace saved sp with true return address. */ + " movq %rax, 152(%rsp)\n" + RESTORE_REGS_STRING + " popfq\n" #else - " pushf\n" - SAVE_REGS_STRING - " movl %esp, %eax\n" - " call trampoline_handler\n" - /* Move flags to cs */ - " movl 56(%esp), %edx\n" - " movl %edx, 52(%esp)\n" - /* Replace saved flags with true return address. */ - " movl %eax, 56(%esp)\n" - RESTORE_REGS_STRING - " popf\n" + " pushf\n" + SAVE_REGS_STRING + " movl %esp, %eax\n" + " call trampoline_handler\n" + /* Move flags to cs */ + " movl 56(%esp), %edx\n" + " movl %edx, 52(%esp)\n" + /* Replace saved flags with true return address. */ + " movl %eax, 56(%esp)\n" + RESTORE_REGS_STRING + " popf\n" #endif - " ret\n"); -} -NOKPROBE_SYMBOL(kretprobe_trampoline_holder); + " ret\n" + ".size kretprobe_trampoline, .-kretprobe_trampoline\n" +); NOKPROBE_SYMBOL(kretprobe_trampoline); /*
