mirror of https://github.com/torvalds/linux.git
508a92741a
This patch fixes a crash caused by an interrupt coming in when an IRQ stack is being torn down. When this happens, handle_signal will loop, setting up the IRQ stack again because the tearing down had finished, and handling whatever signals had come in. However, to_irq_stack returns a mask of pending signals to be handled, plus bit zero is set if the IRQ stack was already active, and thus shouldn't be torn down. This causes a problem because when handle_signal goes around the loop, sig will be zero, and to_irq_stack will duly set bit zero in the returned mask, faking handle_signal into believing that it shouldn't tear down the IRQ stack and return thread_info pointers back to their original values. This will eventually cause a crash, as the IRQ stack thread_info will continue pointing to the original task_struct and an interrupt will look into it after it has been freed. The fix is to stop passing a signal number into to_irq_stack. Rather, the pending signals mask is initialized beforehand with the bit for sig already set. References to sig in to_irq_stack can be replaced with references to the mask. [akpm@linux-foundation.org: use UL] Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| drivers | ||
| include | ||
| skas | ||
| sys-i386 | ||
| sys-x86_64 | ||
| Makefile | ||
| aio.c | ||
| elf_aux.c | ||
| execvp.c | ||
| file.c | ||
| helper.c | ||
| irq.c | ||
| main.c | ||
| mem.c | ||
| process.c | ||
| sigio.c | ||
| signal.c | ||
| start_up.c | ||
| time.c | ||
| tls.c | ||
| trap.c | ||
| tt.c | ||
| tty.c | ||
| tty_log.c | ||
| uaccess.c | ||
| umid.c | ||
| user_syms.c | ||
| util.c | ||