![Himangi Saraogi](/assets/img/avatar_default.png)
ARRAY_SIZE is more concise to use when the size of an array is divided by the size of its type or the size of its first element. The semantic patch that makes this change is as follows: // <smpl> @i@ @@ @@ type T; T[] E; @@ - (sizeof(E)/sizeof(T)) + ARRAY_SIZE(E) // </smpl> Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
402 lines
9.8 KiB
C
402 lines
9.8 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/kprobes.h>
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#include <linux/kdebug.h>
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#include <linux/module.h>
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#include <linux/reboot.h>
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#include <linux/uaccess.h>
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#include <linux/ptrace.h>
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#include <asm/stack.h>
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#include <asm/traps.h>
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#include <asm/setup.h>
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#include <arch/interrupts.h>
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#include <arch/spr_def.h>
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#include <arch/opcode.h>
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void __init trap_init(void)
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{
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/* Nothing needed here since we link code at .intrpt */
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}
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int unaligned_fixup = 1;
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static int __init setup_unaligned_fixup(char *str)
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{
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/*
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* Say "=-1" to completely disable it. If you just do "=0", we
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* will still parse the instruction, then fire a SIGBUS with
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* the correct address from inside the single_step code.
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*/
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if (kstrtoint(str, 0, &unaligned_fixup) != 0)
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return 0;
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pr_info("Fixups for unaligned data accesses are %s\n",
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unaligned_fixup >= 0 ?
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(unaligned_fixup ? "enabled" : "disabled") :
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"completely disabled");
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return 1;
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}
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__setup("unaligned_fixup=", setup_unaligned_fixup);
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#if CHIP_HAS_TILE_DMA()
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static int dma_disabled;
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static int __init nodma(char *str)
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{
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pr_info("User-space DMA is disabled\n");
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dma_disabled = 1;
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return 1;
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}
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__setup("nodma", nodma);
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/* How to decode SPR_GPV_REASON */
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#define IRET_ERROR (1U << 31)
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#define MT_ERROR (1U << 30)
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#define MF_ERROR (1U << 29)
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#define SPR_INDEX ((1U << 15) - 1)
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#define SPR_MPL_SHIFT 9 /* starting bit position for MPL encoded in SPR */
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/*
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* See if this GPV is just to notify the kernel of SPR use and we can
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* retry the user instruction after adjusting some MPLs suitably.
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*/
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static int retry_gpv(unsigned int gpv_reason)
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{
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int mpl;
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if (gpv_reason & IRET_ERROR)
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return 0;
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BUG_ON((gpv_reason & (MT_ERROR|MF_ERROR)) == 0);
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mpl = (gpv_reason & SPR_INDEX) >> SPR_MPL_SHIFT;
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if (mpl == INT_DMA_NOTIFY && !dma_disabled) {
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/* User is turning on DMA. Allow it and retry. */
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printk(KERN_DEBUG "Process %d/%s is now enabled for DMA\n",
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current->pid, current->comm);
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BUG_ON(current->thread.tile_dma_state.enabled);
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current->thread.tile_dma_state.enabled = 1;
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grant_dma_mpls();
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return 1;
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}
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return 0;
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}
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#endif /* CHIP_HAS_TILE_DMA() */
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extern tile_bundle_bits bpt_code;
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asm(".pushsection .rodata.bpt_code,\"a\";"
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".align 8;"
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"bpt_code: bpt;"
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".size bpt_code,.-bpt_code;"
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".popsection");
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static int special_ill(tile_bundle_bits bundle, int *sigp, int *codep)
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{
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int sig, code, maxcode;
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if (bundle == bpt_code) {
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*sigp = SIGTRAP;
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*codep = TRAP_BRKPT;
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return 1;
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}
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/* If it's a "raise" bundle, then "ill" must be in pipe X1. */
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#ifdef __tilegx__
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if ((bundle & TILEGX_BUNDLE_MODE_MASK) != 0)
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return 0;
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if (get_Opcode_X1(bundle) != RRR_0_OPCODE_X1)
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return 0;
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if (get_RRROpcodeExtension_X1(bundle) != UNARY_RRR_0_OPCODE_X1)
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return 0;
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if (get_UnaryOpcodeExtension_X1(bundle) != ILL_UNARY_OPCODE_X1)
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return 0;
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#else
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if (bundle & TILEPRO_BUNDLE_Y_ENCODING_MASK)
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return 0;
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if (get_Opcode_X1(bundle) != SHUN_0_OPCODE_X1)
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return 0;
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if (get_UnShOpcodeExtension_X1(bundle) != UN_0_SHUN_0_OPCODE_X1)
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return 0;
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if (get_UnOpcodeExtension_X1(bundle) != ILL_UN_0_SHUN_0_OPCODE_X1)
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return 0;
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#endif
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/* Check that the magic distinguishers are set to mean "raise". */
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if (get_Dest_X1(bundle) != 29 || get_SrcA_X1(bundle) != 37)
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return 0;
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/* There must be an "addli zero, zero, VAL" in X0. */
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if (get_Opcode_X0(bundle) != ADDLI_OPCODE_X0)
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return 0;
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if (get_Dest_X0(bundle) != TREG_ZERO)
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return 0;
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if (get_SrcA_X0(bundle) != TREG_ZERO)
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return 0;
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/*
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* Validate the proposed signal number and si_code value.
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* Note that we embed these in the static instruction itself
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* so that we perturb the register state as little as possible
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* at the time of the actual fault; it's unlikely you'd ever
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* need to dynamically choose which kind of fault to raise
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* from user space.
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*/
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sig = get_Imm16_X0(bundle) & 0x3f;
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switch (sig) {
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case SIGILL:
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maxcode = NSIGILL;
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break;
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case SIGFPE:
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maxcode = NSIGFPE;
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break;
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case SIGSEGV:
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maxcode = NSIGSEGV;
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break;
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case SIGBUS:
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maxcode = NSIGBUS;
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break;
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case SIGTRAP:
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maxcode = NSIGTRAP;
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break;
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default:
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return 0;
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}
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code = (get_Imm16_X0(bundle) >> 6) & 0xf;
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if (code <= 0 || code > maxcode)
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return 0;
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/* Make it the requested signal. */
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*sigp = sig;
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*codep = code | __SI_FAULT;
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return 1;
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}
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static const char *const int_name[] = {
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[INT_MEM_ERROR] = "Memory error",
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[INT_ILL] = "Illegal instruction",
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[INT_GPV] = "General protection violation",
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[INT_UDN_ACCESS] = "UDN access",
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[INT_IDN_ACCESS] = "IDN access",
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#if CHIP_HAS_SN()
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[INT_SN_ACCESS] = "SN access",
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#endif
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[INT_SWINT_3] = "Software interrupt 3",
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[INT_SWINT_2] = "Software interrupt 2",
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[INT_SWINT_0] = "Software interrupt 0",
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[INT_UNALIGN_DATA] = "Unaligned data",
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[INT_DOUBLE_FAULT] = "Double fault",
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#ifdef __tilegx__
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[INT_ILL_TRANS] = "Illegal virtual address",
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#endif
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};
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static int do_bpt(struct pt_regs *regs)
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{
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unsigned long bundle, bcode, bpt;
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bundle = *(unsigned long *)instruction_pointer(regs);
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/*
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* bpt shoule be { bpt; nop }, which is 0x286a44ae51485000ULL.
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* we encode the unused least significant bits for other purpose.
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*/
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bpt = bundle & ~((1ULL << 12) - 1);
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if (bpt != TILE_BPT_BUNDLE)
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return 0;
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bcode = bundle & ((1ULL << 12) - 1);
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/*
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* notify the kprobe handlers, if instruction is likely to
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* pertain to them.
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*/
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switch (bcode) {
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/* breakpoint_insn */
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case 0:
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notify_die(DIE_BREAK, "debug", regs, bundle,
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INT_ILL, SIGTRAP);
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break;
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/* compiled_bpt */
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case DIE_COMPILED_BPT:
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notify_die(DIE_COMPILED_BPT, "debug", regs, bundle,
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INT_ILL, SIGTRAP);
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break;
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/* breakpoint2_insn */
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case DIE_SSTEPBP:
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notify_die(DIE_SSTEPBP, "single_step", regs, bundle,
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INT_ILL, SIGTRAP);
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break;
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default:
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return 0;
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}
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return 1;
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}
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void __kprobes do_trap(struct pt_regs *regs, int fault_num,
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unsigned long reason)
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{
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siginfo_t info = { 0 };
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int signo, code;
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unsigned long address = 0;
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tile_bundle_bits instr;
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int is_kernel = !user_mode(regs);
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/* Handle breakpoints, etc. */
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if (is_kernel && fault_num == INT_ILL && do_bpt(regs))
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return;
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/* Re-enable interrupts, if they were previously enabled. */
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if (!(regs->flags & PT_FLAGS_DISABLE_IRQ))
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local_irq_enable();
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/*
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* If it hits in kernel mode and we can't fix it up, just exit the
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* current process and hope for the best.
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*/
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if (is_kernel) {
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const char *name;
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char buf[100];
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if (fixup_exception(regs)) /* ILL_TRANS or UNALIGN_DATA */
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return;
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if (fault_num >= 0 &&
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fault_num < ARRAY_SIZE(int_name) &&
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int_name[fault_num] != NULL)
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name = int_name[fault_num];
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else
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name = "Unknown interrupt";
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if (fault_num == INT_GPV)
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snprintf(buf, sizeof(buf), "; GPV_REASON %#lx", reason);
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#ifdef __tilegx__
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else if (fault_num == INT_ILL_TRANS)
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snprintf(buf, sizeof(buf), "; address %#lx", reason);
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#endif
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else
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buf[0] = '\0';
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pr_alert("Kernel took bad trap %d (%s) at PC %#lx%s\n",
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fault_num, name, regs->pc, buf);
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show_regs(regs);
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do_exit(SIGKILL); /* FIXME: implement i386 die() */
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return;
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}
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switch (fault_num) {
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case INT_MEM_ERROR:
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signo = SIGBUS;
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code = BUS_OBJERR;
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break;
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case INT_ILL:
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if (copy_from_user(&instr, (void __user *)regs->pc,
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sizeof(instr))) {
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pr_err("Unreadable instruction for INT_ILL:"
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" %#lx\n", regs->pc);
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do_exit(SIGKILL);
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return;
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}
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if (!special_ill(instr, &signo, &code)) {
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signo = SIGILL;
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code = ILL_ILLOPC;
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}
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address = regs->pc;
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break;
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case INT_GPV:
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#if CHIP_HAS_TILE_DMA()
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if (retry_gpv(reason))
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return;
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#endif
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/*FALLTHROUGH*/
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case INT_UDN_ACCESS:
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case INT_IDN_ACCESS:
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#if CHIP_HAS_SN()
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case INT_SN_ACCESS:
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#endif
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signo = SIGILL;
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code = ILL_PRVREG;
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address = regs->pc;
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break;
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case INT_SWINT_3:
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case INT_SWINT_2:
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case INT_SWINT_0:
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signo = SIGILL;
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code = ILL_ILLTRP;
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address = regs->pc;
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break;
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case INT_UNALIGN_DATA:
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#ifndef __tilegx__ /* Emulated support for single step debugging */
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if (unaligned_fixup >= 0) {
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struct single_step_state *state =
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current_thread_info()->step_state;
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if (!state ||
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(void __user *)(regs->pc) != state->buffer) {
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single_step_once(regs);
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return;
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}
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}
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#endif
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signo = SIGBUS;
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code = BUS_ADRALN;
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address = 0;
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break;
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case INT_DOUBLE_FAULT:
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/*
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* For double fault, "reason" is actually passed as
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* SYSTEM_SAVE_K_2, the hypervisor's double-fault info, so
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* we can provide the original fault number rather than
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* the uninteresting "INT_DOUBLE_FAULT" so the user can
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* learn what actually struck while PL0 ICS was set.
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*/
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fault_num = reason;
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signo = SIGILL;
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code = ILL_DBLFLT;
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address = regs->pc;
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break;
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#ifdef __tilegx__
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case INT_ILL_TRANS: {
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/* Avoid a hardware erratum with the return address stack. */
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fill_ra_stack();
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signo = SIGSEGV;
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address = reason;
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code = SEGV_MAPERR;
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break;
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}
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#endif
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default:
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panic("Unexpected do_trap interrupt number %d", fault_num);
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return;
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}
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info.si_signo = signo;
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info.si_code = code;
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info.si_addr = (void __user *)address;
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if (signo == SIGILL)
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info.si_trapno = fault_num;
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if (signo != SIGTRAP)
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trace_unhandled_signal("trap", regs, address, signo);
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force_sig_info(signo, &info, current);
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}
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void kernel_double_fault(int dummy, ulong pc, ulong lr, ulong sp, ulong r52)
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{
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_dump_stack(dummy, pc, lr, sp, r52);
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pr_emerg("Double fault: exiting\n");
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machine_halt();
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}
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