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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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abc7e40c81
If a interrupt chip utilizes chip->buslock then free_irq() can deadlock in the following way: CPU0 CPU1 interrupt(X) (Shared or spurious) free_irq(X) interrupt_thread(X) chip_bus_lock(X) irq_finalize_oneshot(X) chip_bus_lock(X) synchronize_irq(X) synchronize_irq() waits for the interrupt thread to complete, i.e. forever. Solution is simple: Drop chip_bus_lock() before calling synchronize_irq() as we do with the irq_desc lock. There is nothing to be protected after the point where irq_desc lock has been released. This adds chip_bus_lock/unlock() to the remove_irq() code path, but that's actually correct in the case where remove_irq() is called on such an interrupt. The current users of remove_irq() are not affected as none of those interrupts is on a chip which requires buslock. Reported-by: Fredrik Markström <fredrik.markstrom@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org |
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| .. | ||
| autoprobe.c | ||
| chip.c | ||
| cpuhotplug.c | ||
| debug.h | ||
| devres.c | ||
| dummychip.c | ||
| generic-chip.c | ||
| handle.c | ||
| internals.h | ||
| irqdesc.c | ||
| irqdomain.c | ||
| Kconfig | ||
| Makefile | ||
| manage.c | ||
| migration.c | ||
| msi.c | ||
| pm.c | ||
| proc.c | ||
| resend.c | ||
| settings.h | ||
| spurious.c | ||