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Commit9d1988ca87("powerpc/64: treat low kernel text as irqs soft-masked") ends up catching too much code, including ret_from_fork, and parts of interrupt and syscall return that do not expect to be interrupts to be soft-masked. If an interrupt gets marked pending, and then the code proceeds out of the implicit soft-masked region it will fail to deal with the pending interrupt. Fix this by adding a new table of addresses which explicitly marks the regions of code that are soft masked. This table is only checked for interrupts that below __end_soft_masked, so most kernel interrupts will not have the overhead of the table search. Fixes:9d1988ca87("powerpc/64: treat low kernel text as irqs soft-masked") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210630074621.2109197-5-npiggin@gmail.com
56 lines
1.3 KiB
C
56 lines
1.3 KiB
C
#include <asm/interrupt.h>
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#include <asm/kprobes.h>
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struct soft_mask_table_entry {
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unsigned long start;
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unsigned long end;
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};
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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 soft_mask_table_entry __start___soft_mask_table[];
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extern struct soft_mask_table_entry __stop___soft_mask_table[];
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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 soft mask table */
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bool search_kernel_soft_mask_table(unsigned long addr)
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{
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struct soft_mask_table_entry *smte = __start___soft_mask_table;
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while (smte < __stop___soft_mask_table) {
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unsigned long start = smte->start;
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unsigned long end = smte->end;
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if (addr >= start && addr < end)
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return true;
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smte++;
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}
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return false;
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}
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NOKPROBE_SYMBOL(search_kernel_soft_mask_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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