diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-05-21 22:05:50 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:18 +0200 |
| commit | 9628f26baef262a49d877e3785e8b88d241bc064 (patch) | |
| tree | 332d2f9e3b7b0a538dd1b992a08e6afd08058ae3 | |
| parent | fa95a0cb0423661eb615b6ac1e9882ce9a75719a (diff) | |
| download | linux-9628f26baef262a49d877e3785e8b88d241bc064.tar.gz | |
x86/entry/64: Remove TRACE_IRQS_*_DEBUG
Since INT3/#BP no longer runs on an IST, this workaround is no longer
required.
Tested by running lockdep+ftrace as described in the initial commit:
5963e317b1e9 ("ftrace/x86: Do not change stacks in DEBUG when calling lockdep")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202120.319418546@linutronix.de
| -rw-r--r-- | arch/x86/entry/entry_64.S | 48 |
1 files changed, 3 insertions, 45 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 29a8a83a6f5fdb..fb7f1262834657 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -68,44 +68,6 @@ SYM_CODE_END(native_usergs_sysret64) .endm /* - * When dynamic function tracer is enabled it will add a breakpoint - * to all locations that it is about to modify, sync CPUs, update - * all the code, sync CPUs, then remove the breakpoints. In this time - * if lockdep is enabled, it might jump back into the debug handler - * outside the updating of the IST protection. (TRACE_IRQS_ON/OFF). - * - * We need to change the IDT table before calling TRACE_IRQS_ON/OFF to - * make sure the stack pointer does not get reset back to the top - * of the debug stack, and instead just reuses the current stack. - */ -#if defined(CONFIG_DYNAMIC_FTRACE) && defined(CONFIG_TRACE_IRQFLAGS) - -.macro TRACE_IRQS_OFF_DEBUG - call debug_stack_set_zero - TRACE_IRQS_OFF - call debug_stack_reset -.endm - -.macro TRACE_IRQS_ON_DEBUG - call debug_stack_set_zero - TRACE_IRQS_ON - call debug_stack_reset -.endm - -.macro TRACE_IRQS_IRETQ_DEBUG - btl $9, EFLAGS(%rsp) /* interrupts off? */ - jnc 1f - TRACE_IRQS_ON_DEBUG -1: -.endm - -#else -# define TRACE_IRQS_OFF_DEBUG TRACE_IRQS_OFF -# define TRACE_IRQS_ON_DEBUG TRACE_IRQS_ON -# define TRACE_IRQS_IRETQ_DEBUG TRACE_IRQS_IRETQ -#endif - -/* * 64-bit SYSCALL instruction entry. Up to 6 arguments in registers. * * This is the only entry point used for 64-bit system calls. The @@ -500,11 +462,7 @@ SYM_CODE_START(\asmsym) UNWIND_HINT_REGS - .if \vector == X86_TRAP_DB - TRACE_IRQS_OFF_DEBUG - .else - TRACE_IRQS_OFF - .endif + TRACE_IRQS_OFF movq %rsp, %rdi /* pt_regs pointer */ @@ -924,7 +882,7 @@ SYM_CODE_END(paranoid_entry) SYM_CODE_START_LOCAL(paranoid_exit) UNWIND_HINT_REGS DISABLE_INTERRUPTS(CLBR_ANY) - TRACE_IRQS_OFF_DEBUG + TRACE_IRQS_OFF testl %ebx, %ebx /* swapgs needed? */ jnz .Lparanoid_exit_no_swapgs TRACE_IRQS_IRETQ @@ -933,7 +891,7 @@ SYM_CODE_START_LOCAL(paranoid_exit) SWAPGS_UNSAFE_STACK jmp restore_regs_and_return_to_kernel .Lparanoid_exit_no_swapgs: - TRACE_IRQS_IRETQ_DEBUG + TRACE_IRQS_IRETQ /* Always restore stashed CR3 value (see paranoid_entry) */ RESTORE_CR3 scratch_reg=%rbx save_reg=%r14 jmp restore_regs_and_return_to_kernel |