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| author | Will Deacon <will.deacon@arm.com> | 2019-02-26 15:35:00 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-09 12:21:13 +0200 |
| commit | a22d570aee77ae626e4d3532478ae8058a24bdb3 (patch) | |
| tree | 0e56e10e67dab8e3cc56fa4add1aa28c2c146e65 /arch/arm64/kernel/debug-monitors.c | |
| parent | arm64: debug: Separate debug hooks based on target exception level (diff) | |
| download | linux-a22d570aee77ae626e4d3532478ae8058a24bdb3.tar.xz linux-a22d570aee77ae626e4d3532478ae8058a24bdb3.zip | |
arm64: kprobes: Avoid calling kprobes debug handlers explicitly
Kprobes bypasses our debug hook registration code so that it doesn't
get tangled up with recursive debug exceptions from things like lockdep:
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-February/324385.html
However, since then, (a) the hook list has become RCU protected and (b)
the kprobes hooks were found not to filter out exceptions from userspace
correctly. On top of that, the step handler is invoked directly from
single_step_handler(), which *does* use the debug hook list, so it's
clearly not the end of the world.
For now, have kprobes use the debug hook registration API like everybody
else. We can revisit this in the future if this is found to limit
coverage significantly.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/debug-monitors.c')
| -rw-r--r-- | arch/arm64/kernel/debug-monitors.c | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index 9b3fd7fa5b43..f4d8cda8830d 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -258,10 +258,6 @@ static int single_step_handler(unsigned long unused, unsigned int esr, if (!reinstall_suspended_bps(regs)) return 0; -#ifdef CONFIG_KPROBES - if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED) - handler_found = true; -#endif if (!handler_found && call_step_hook(regs, esr) == DBG_HOOK_HANDLED) handler_found = true; @@ -337,12 +333,6 @@ static int brk_handler(unsigned long unused, unsigned int esr, { bool handler_found = false; -#ifdef CONFIG_KPROBES - if ((esr & BRK64_ESR_MASK) == BRK64_ESR_KPROBES) { - if (kprobe_breakpoint_handler(regs, esr) == DBG_HOOK_HANDLED) - handler_found = true; - } -#endif if (!handler_found && call_break_hook(regs, esr) == DBG_HOOK_HANDLED) handler_found = true; |