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a994eddb94
Currently psw_idle does not allocate a stack frame and does not save its r14 and r15 into the save area. Even though this is valid from call ABI point of view, because psw_idle does not make any calls explicitly, in reality psw_idle is an entry point for controlled transition into serving interrupts. So, in practice, psw_idle stack frame is analyzed during stack unwinding. Depending on build options that r14 slot in the save area of psw_idle might either contain a value saved by previous sibling call or complete garbage. [task 0000038000003c28] do_ext_irq+0xd6/0x160 [task 0000038000003c78] ext_int_handler+0xba/0xe8 [task *0000038000003dd8] psw_idle_exit+0x0/0x8 <-- pt_regs ([task 0000038000003dd8] 0x0) [task 0000038000003e10] default_idle_call+0x42/0x148 [task 0000038000003e30] do_idle+0xce/0x160 [task 0000038000003e70] cpu_startup_entry+0x36/0x40 [task 0000038000003ea0] arch_call_rest_init+0x76/0x80 So, to make a stacktrace nicer and actually point for the real caller of psw_idle in this frequently occurring case, make psw_idle save its r14. [task 0000038000003c28] do_ext_irq+0xd6/0x160 [task 0000038000003c78] ext_int_handler+0xba/0xe8 [task *0000038000003dd8] psw_idle_exit+0x0/0x6 <-- pt_regs ([task 0000038000003dd8] arch_cpu_idle+0x3c/0xd0) [task 0000038000003e10] default_idle_call+0x42/0x148 [task 0000038000003e30] do_idle+0xce/0x160 [task 0000038000003e70] cpu_startup_entry+0x36/0x40 [task 0000038000003ea0] arch_call_rest_init+0x76/0x80 Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> |
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| appldata | ||
| boot | ||
| configs | ||
| crypto | ||
| hypfs | ||
| include | ||
| kernel | ||
| kvm | ||
| lib | ||
| mm | ||
| net | ||
| pci | ||
| purgatory | ||
| tools | ||
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| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||