diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-06-18 01:51:08 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-25 00:06:56 +1000 |
| commit | f23699c93becd746295aaa506537882a46a62219 (patch) | |
| tree | ea44289996524915c83e6876b39babbe6a640ff8 /arch/powerpc/include | |
| parent | 63e40806eea984f770c992120bbfd71b589ea580 (diff) | |
powerpc/64: allow alternate return locations for soft-masked interrupts
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
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/interrupt.h | 13 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/ppc_asm.h | 8 |
2 files changed, 21 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h index de36fb5d9c51..a4bf6c0013bb 100644 --- a/arch/powerpc/include/asm/interrupt.h +++ b/arch/powerpc/include/asm/interrupt.h @@ -73,6 +73,11 @@ #include <asm/kprobes.h> #include <asm/runlatch.h> +#ifdef CONFIG_PPC64 +extern char __end_soft_masked[]; +unsigned long search_kernel_restart_table(unsigned long addr); +#endif + #ifdef CONFIG_PPC_BOOK3S_64 static inline void srr_regs_clobbered(void) { @@ -270,6 +275,14 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter */ #ifdef CONFIG_PPC64 + if (arch_irq_disabled_regs(regs)) { + unsigned long rst = search_kernel_restart_table(regs->nip); + if (rst) + regs_set_return_ip(regs, rst); + } +#endif + +#ifdef CONFIG_PPC64 if (nmi_disables_ftrace(regs)) this_cpu_set_ftrace_enabled(state->ftrace_enabled); diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index d6739d700f0a..c9c2c36c1f8f 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -762,6 +762,14 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96) stringify_in_c(.long (_target) - . ;) \ stringify_in_c(.previous) +#define RESTART_TABLE(_start, _end, _target) \ + stringify_in_c(.section __restart_table,"a";)\ + stringify_in_c(.balign 8;) \ + stringify_in_c(.llong (_start);) \ + stringify_in_c(.llong (_end);) \ + stringify_in_c(.llong (_target);) \ + stringify_in_c(.previous) + #ifdef CONFIG_PPC_FSL_BOOK3E #define BTB_FLUSH(reg) \ lis reg,BUCSR_INIT@h; \ |