1. 01 Apr, 2020 3 commits
    • Nicholas Piggin's avatar
      powerpc/64s/exception: Introduce INT_DEFINE parameter block for code generation · a42a239d
      Nicholas Piggin authored
      The code generation macro arguments are difficult to read, and
      defaults can't easily be used.
      
      This introduces a block where parameters can be set for interrupt
      handler code generation by the subsequent macros, and adds the first
      generation macro for interrupt entry.
      
      One interrupt handler is converted to the new macros to demonstrate
      the change, the rest will be coverted all at once.
      
      No generated code change.
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/20200225173541.1549955-2-npiggin@gmail.com
      a42a239d
    • Nicholas Piggin's avatar
      powerpc/64: mark emergency stacks valid to unwind · a2e36683
      Nicholas Piggin authored
      Before:
      
        WARNING: CPU: 0 PID: 494 at arch/powerpc/kernel/irq.c:343
        CPU: 0 PID: 494 Comm: a Tainted: G        W
        NIP:  c00000000001ed2c LR: c000000000d13190 CTR: c00000000003f910
        REGS: c0000001fffd3870 TRAP: 0700   Tainted: G        W
        MSR:  8000000000021003 <SF,ME,RI,LE>  CR: 28000488  XER: 00000000
        CFAR: c00000000001ec90 IRQMASK: 0
        GPR00: c000000000aeb12c c0000001fffd3b00 c0000000012ba300 0000000000000000
        GPR04: 0000000000000000 0000000000000000 000000010bd207c8 6b00696e74657272
        GPR08: 0000000000000000 0000000000000000 0000000000000000 efbeadde00000000
        GPR12: 0000000000000000 c0000000014a0000 0000000000000000 0000000000000000
        GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
        GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
        GPR24: 0000000000000000 0000000000000000 0000000000000000 000000010bd207bc
        GPR28: 0000000000000000 c00000000148a898 0000000000000000 c0000001ffff3f50
        NIP [c00000000001ed2c] arch_local_irq_restore.part.0+0xac/0x100
        LR [c000000000d13190] _raw_spin_unlock_irqrestore+0x50/0xc0
        Call Trace:
        Instruction dump:
        60000000 7d2000a6 71298000 41820068 39200002 7d210164 4bffff9c 60000000
        60000000 7d2000a6 71298000 4c820020 <0fe00000> 4e800020 60000000 60000000
      
      After:
      
        WARNING: CPU: 0 PID: 499 at arch/powerpc/kernel/irq.c:343
        CPU: 0 PID: 499 Comm: a Not tainted
        NIP:  c00000000001ed2c LR: c000000000d13210 CTR: c00000000003f980
        REGS: c0000001fffd3870 TRAP: 0700   Not tainted
        MSR:  8000000000021003 <SF,ME,RI,LE>  CR: 28000488  XER: 00000000
        CFAR: c00000000001ec90 IRQMASK: 0
        GPR00: c000000000aeb1ac c0000001fffd3b00 c0000000012ba300 0000000000000000
        GPR04: 0000000000000000 0000000000000000 00000001347607c8 6b00696e74657272
        GPR08: 0000000000000000 0000000000000000 0000000000000000 efbeadde00000000
        GPR12: 0000000000000000 c0000000014a0000 0000000000000000 0000000000000000
        GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
        GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
        GPR24: 0000000000000000 0000000000000000 0000000000000000 00000001347607bc
        GPR28: 0000000000000000 c00000000148a898 0000000000000000 c0000001ffff3f50
        NIP [c00000000001ed2c] arch_local_irq_restore.part.0+0xac/0x100
        LR [c000000000d13210] _raw_spin_unlock_irqrestore+0x50/0xc0
        Call Trace:
        [c0000001fffd3b20] [c000000000aeb1ac] of_find_property+0x6c/0x90
        [c0000001fffd3b70] [c000000000aeb1f0] of_get_property+0x20/0x40
        [c0000001fffd3b90] [c000000000042cdc] rtas_token+0x3c/0x70
        [c0000001fffd3bb0] [c0000000000dc318] fwnmi_release_errinfo+0x28/0x70
        [c0000001fffd3c10] [c0000000000dcd8c] pseries_machine_check_realmode+0x1dc/0x540
        [c0000001fffd3cd0] [c00000000003fe04] machine_check_early+0x54/0x70
        [c0000001fffd3d00] [c000000000008384] machine_check_early_common+0x134/0x1f0
        --- interrupt: 200 at 0x1347607c8
            LR = 0x7fffafbd8328
        Instruction dump:
        60000000 7d2000a6 71298000 41820068 39200002 7d210164 4bffff9c 60000000
        60000000 7d2000a6 71298000 4c820020 <0fe00000> 4e800020 60000000 60000000
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/20200325104144.158362-1-npiggin@gmail.com
      a2e36683
    • Michael Ellerman's avatar
      powerpc/64/tm: Don't let userspace set regs->trap via sigreturn · c7def7fb
      Michael Ellerman authored
      In restore_tm_sigcontexts() we take the trap value directly from the
      user sigcontext with no checking:
      
      	err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
      
      This means we can be in the kernel with an arbitrary regs->trap value.
      
      Although that's not immediately problematic, there is a risk we could
      trigger one of the uses of CHECK_FULL_REGS():
      
      	#define CHECK_FULL_REGS(regs)	BUG_ON(regs->trap & 1)
      
      It can also cause us to unnecessarily save non-volatile GPRs again in
      save_nvgprs(), which shouldn't be problematic but is still wrong.
      
      It's also possible it could trick the syscall restart machinery, which
      relies on regs->trap not being == 0xc00 (see 9a81c16b ("powerpc:
      fix double syscall restarts")), though I haven't been able to make
      that happen.
      
      Finally it doesn't match the behaviour of the non-TM case, in
      restore_sigcontext() which zeroes regs->trap.
      
      So change restore_tm_sigcontexts() to zero regs->trap.
      
      This was discovered while testing Nick's upcoming rewrite of the
      syscall entry path. In that series the call to save_nvgprs() prior to
      signal handling (do_notify_resume()) is removed, which leaves the
      low-bit of regs->trap uncleared which can then trigger the FULL_REGS()
      WARNs in setup_tm_sigcontexts().
      
      Fixes: 2b0a576d ("powerpc: Add new transactional memory state to the signal context")
      Cc: stable@vger.kernel.org # v3.9+
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/20200401023836.3286664-1-mpe@ellerman.id.au
      c7def7fb
  2. 27 Mar, 2020 3 commits
  3. 26 Mar, 2020 17 commits
  4. 25 Mar, 2020 17 commits