diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-06-10 08:37:01 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:29 +0200 |
| commit | f0178fc01fe46bab6a95415f5647d1a74efcad1b (patch) | |
| tree | bf263d8cacf2ada33dea4cbc16ee5fd46b0109d4 /arch/x86/kernel | |
| parent | x86/entry: __always_inline CR2 for noinstr (diff) | |
| download | linux-f0178fc01fe46bab6a95415f5647d1a74efcad1b.tar.xz linux-f0178fc01fe46bab6a95415f5647d1a74efcad1b.zip | |
x86/entry: Unbreak __irqentry_text_start/end magic
The entry rework moved interrupt entry code from the irqentry to the
noinstr section which made the irqentry section empty.
This breaks boundary checks which rely on the __irqentry_text_start/end
markers to find out whether a function in a stack trace is
interrupt/exception entry code. This affects the function graph tracer and
filter_irq_stacks().
As the IDT entry points are all sequentialy emitted this is rather simple
to unbreak by injecting __irqentry_text_start/end as global labels.
To make this work correctly:
- Remove the IRQENTRY_TEXT section from the x86 linker script
- Define __irqentry so it breaks the build if it's used
- Adjust the entry mirroring in PTI
- Remove the redundant kprobes and unwinder bound checks
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/unwind_frame.c | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 1 |
4 files changed, 2 insertions, 18 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 85de8fa69b24..3bafe1bd4dc7 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1073,13 +1073,6 @@ NOKPROBE_SYMBOL(kprobe_fault_handler); int __init arch_populate_kprobe_blacklist(void) { - int ret; - - ret = kprobe_add_area_blacklist((unsigned long)__irqentry_text_start, - (unsigned long)__irqentry_text_end); - if (ret) - return ret; - return kprobe_add_area_blacklist((unsigned long)__entry_text_start, (unsigned long)__entry_text_end); } diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 234f58e0fe8c..321c19950285 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -286,9 +286,7 @@ static int can_optimize(unsigned long paddr) * stack handling and registers setup. */ if (((paddr >= (unsigned long)__entry_text_start) && - (paddr < (unsigned long)__entry_text_end)) || - ((paddr >= (unsigned long)__irqentry_text_start) && - (paddr < (unsigned long)__irqentry_text_end))) + (paddr < (unsigned long)__entry_text_end))) return 0; /* Check there is enough space for a relative jump. */ diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 54226110bc7f..722a85f3b2dd 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -74,13 +74,7 @@ static bool in_entry_code(unsigned long ip) { char *addr = (char *)ip; - if (addr >= __entry_text_start && addr < __entry_text_end) - return true; - - if (addr >= __irqentry_text_start && addr < __irqentry_text_end) - return true; - - return false; + return addr >= __entry_text_start && addr < __entry_text_end; } static inline unsigned long *last_frame(struct unwind_state *state) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 1bf7e312361f..b4c6b6f35548 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -134,7 +134,6 @@ SECTIONS KPROBES_TEXT ALIGN_ENTRY_TEXT_BEGIN ENTRY_TEXT - IRQENTRY_TEXT ALIGN_ENTRY_TEXT_END SOFTIRQENTRY_TEXT *(.fixup) |