f23699c93b
The exception table fixup adjusts a failed page fault's interrupt return location if it was taken at an address specified in the exception table, to a corresponding fixup handler address. Introduce a variation of that idea which adds a fixup table for NMIs and soft-masked asynchronous interrupts. This will be used to protect certain critical sections that are sensitive to being clobbered by interrupts coming in (due to using the same SPRs and/or irq soft-mask state). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-10-npiggin@gmail.com
31 lines
732 B
C
31 lines
732 B
C
#include <asm/interrupt.h>
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#include <asm/kprobes.h>
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struct restart_table_entry {
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unsigned long start;
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unsigned long end;
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unsigned long fixup;
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};
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extern struct restart_table_entry __start___restart_table[];
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extern struct restart_table_entry __stop___restart_table[];
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/* Given an address, look for it in the kernel exception table */
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unsigned long search_kernel_restart_table(unsigned long addr)
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{
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struct restart_table_entry *rte = __start___restart_table;
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while (rte < __stop___restart_table) {
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unsigned long start = rte->start;
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unsigned long end = rte->end;
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unsigned long fixup = rte->fixup;
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if (addr >= start && addr < end)
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return fixup;
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rte++;
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}
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return 0;
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}
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NOKPROBE_SYMBOL(search_kernel_restart_table);
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