4dcc29e157
Problem: An application violating the architectural rules regarding operation dependencies and having specific Register Stack Engine (RSE) state at the time of the violation, may result in an illegal operation fault and invalid RSE state. Such faults may initiate a cascade of repeated illegal operation faults within OS interruption handlers. The specific behavior is OS dependent. Implication: An application causing an illegal operation fault with specific RSE state may result in a series of illegal operation faults and an eventual OS stack overflow condition. Workaround: OS interruption handlers that switch to kernel backing store implement a check for invalid RSE state to avoid the series of illegal operation faults. The core of the workaround is the RSE_WORKAROUND code sequence inserted into each invocation of the SAVE_MIN_WITH_COVER and SAVE_MIN_WITH_COVER_R19 macros. This sequence includes hard-coded constants that depend on the number of stacked physical registers being 96. The rest of this patch consists of code to disable this workaround should this not be the case (with the presumption that if a future Itanium processor increases the number of registers, it would also remove the need for this patch). Move the start of the RBS up to a mod32 boundary to avoid some corner cases. The dispatch_illegal_op_fault code outgrew the spot it was squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y Move it out to the end of the ivt. Signed-off-by: Tony Luck <tony.luck@intel.com>
237 lines
6.4 KiB
C
237 lines
6.4 KiB
C
/*
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* Instruction-patching support.
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*
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* Copyright (C) 2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*/
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#include <linux/init.h>
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#include <linux/string.h>
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#include <asm/patch.h>
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#include <asm/processor.h>
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#include <asm/sections.h>
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#include <asm/system.h>
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#include <asm/unistd.h>
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/*
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* This was adapted from code written by Tony Luck:
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*
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* The 64-bit value in a "movl reg=value" is scattered between the two words of the bundle
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* like this:
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*
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* 6 6 5 4 3 2 1
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* 3210987654321098765432109876543210987654321098765432109876543210
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* ABBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCDEEEEEFFFFFFFFFGGGGGGG
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*
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* CCCCCCCCCCCCCCCCCCxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
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* xxxxAFFFFFFFFFEEEEEDxGGGGGGGxxxxxxxxxxxxxBBBBBBBBBBBBBBBBBBBBBBB
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*/
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static u64
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get_imm64 (u64 insn_addr)
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{
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u64 *p = (u64 *) (insn_addr & -16); /* mask out slot number */
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return ( (p[1] & 0x0800000000000000UL) << 4) | /*A*/
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((p[1] & 0x00000000007fffffUL) << 40) | /*B*/
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((p[0] & 0xffffc00000000000UL) >> 24) | /*C*/
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((p[1] & 0x0000100000000000UL) >> 23) | /*D*/
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((p[1] & 0x0003e00000000000UL) >> 29) | /*E*/
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((p[1] & 0x07fc000000000000UL) >> 43) | /*F*/
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((p[1] & 0x000007f000000000UL) >> 36); /*G*/
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}
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/* Patch instruction with "val" where "mask" has 1 bits. */
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void
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ia64_patch (u64 insn_addr, u64 mask, u64 val)
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{
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u64 m0, m1, v0, v1, b0, b1, *b = (u64 *) (insn_addr & -16);
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# define insn_mask ((1UL << 41) - 1)
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unsigned long shift;
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b0 = b[0]; b1 = b[1];
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shift = 5 + 41 * (insn_addr % 16); /* 5 bits of template, then 3 x 41-bit instructions */
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if (shift >= 64) {
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m1 = mask << (shift - 64);
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v1 = val << (shift - 64);
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} else {
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m0 = mask << shift; m1 = mask >> (64 - shift);
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v0 = val << shift; v1 = val >> (64 - shift);
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b[0] = (b0 & ~m0) | (v0 & m0);
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}
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b[1] = (b1 & ~m1) | (v1 & m1);
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}
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void
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ia64_patch_imm64 (u64 insn_addr, u64 val)
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{
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/* The assembler may generate offset pointing to either slot 1
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or slot 2 for a long (2-slot) instruction, occupying slots 1
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and 2. */
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insn_addr &= -16UL;
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ia64_patch(insn_addr + 2,
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0x01fffefe000UL, ( ((val & 0x8000000000000000UL) >> 27) /* bit 63 -> 36 */
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| ((val & 0x0000000000200000UL) << 0) /* bit 21 -> 21 */
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| ((val & 0x00000000001f0000UL) << 6) /* bit 16 -> 22 */
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| ((val & 0x000000000000ff80UL) << 20) /* bit 7 -> 27 */
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| ((val & 0x000000000000007fUL) << 13) /* bit 0 -> 13 */));
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ia64_patch(insn_addr + 1, 0x1ffffffffffUL, val >> 22);
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}
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void
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ia64_patch_imm60 (u64 insn_addr, u64 val)
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{
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/* The assembler may generate offset pointing to either slot 1
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or slot 2 for a long (2-slot) instruction, occupying slots 1
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and 2. */
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insn_addr &= -16UL;
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ia64_patch(insn_addr + 2,
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0x011ffffe000UL, ( ((val & 0x0800000000000000UL) >> 23) /* bit 59 -> 36 */
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| ((val & 0x00000000000fffffUL) << 13) /* bit 0 -> 13 */));
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ia64_patch(insn_addr + 1, 0x1fffffffffcUL, val >> 18);
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}
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/*
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* We need sometimes to load the physical address of a kernel
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* object. Often we can convert the virtual address to physical
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* at execution time, but sometimes (either for performance reasons
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* or during error recovery) we cannot to this. Patch the marked
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* bundles to load the physical address.
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*/
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void __init
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ia64_patch_vtop (unsigned long start, unsigned long end)
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{
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s32 *offp = (s32 *) start;
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u64 ip;
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while (offp < (s32 *) end) {
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ip = (u64) offp + *offp;
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/* replace virtual address with corresponding physical address: */
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ia64_patch_imm64(ip, ia64_tpa(get_imm64(ip)));
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ia64_fc((void *) ip);
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++offp;
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}
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ia64_sync_i();
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ia64_srlz_i();
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}
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/*
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* Disable the RSE workaround by turning the conditional branch
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* that we tagged in each place the workaround was used into an
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* unconditional branch.
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*/
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void __init
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ia64_patch_rse (unsigned long start, unsigned long end)
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{
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s32 *offp = (s32 *) start;
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u64 ip, *b;
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while (offp < (s32 *) end) {
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ip = (u64) offp + *offp;
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b = (u64 *)(ip & -16);
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b[1] &= ~0xf800000L;
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ia64_fc((void *) ip);
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++offp;
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}
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ia64_sync_i();
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ia64_srlz_i();
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}
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void __init
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ia64_patch_mckinley_e9 (unsigned long start, unsigned long end)
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{
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static int first_time = 1;
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int need_workaround;
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s32 *offp = (s32 *) start;
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u64 *wp;
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need_workaround = (local_cpu_data->family == 0x1f && local_cpu_data->model == 0);
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if (first_time) {
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first_time = 0;
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if (need_workaround)
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printk(KERN_INFO "Leaving McKinley Errata 9 workaround enabled\n");
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}
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if (need_workaround)
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return;
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while (offp < (s32 *) end) {
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wp = (u64 *) ia64_imva((char *) offp + *offp);
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wp[0] = 0x0000000100000011UL; /* nop.m 0; nop.i 0; br.ret.sptk.many b6 */
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wp[1] = 0x0084006880000200UL;
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wp[2] = 0x0000000100000000UL; /* nop.m 0; nop.i 0; nop.i 0 */
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wp[3] = 0x0004000000000200UL;
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ia64_fc(wp); ia64_fc(wp + 2);
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++offp;
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}
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ia64_sync_i();
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ia64_srlz_i();
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}
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static void __init
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patch_fsyscall_table (unsigned long start, unsigned long end)
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{
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extern unsigned long fsyscall_table[NR_syscalls];
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s32 *offp = (s32 *) start;
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u64 ip;
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while (offp < (s32 *) end) {
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ip = (u64) ia64_imva((char *) offp + *offp);
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ia64_patch_imm64(ip, (u64) fsyscall_table);
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ia64_fc((void *) ip);
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++offp;
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}
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ia64_sync_i();
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ia64_srlz_i();
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}
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static void __init
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patch_brl_fsys_bubble_down (unsigned long start, unsigned long end)
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{
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extern char fsys_bubble_down[];
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s32 *offp = (s32 *) start;
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u64 ip;
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while (offp < (s32 *) end) {
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ip = (u64) offp + *offp;
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ia64_patch_imm60((u64) ia64_imva((void *) ip),
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(u64) (fsys_bubble_down - (ip & -16)) / 16);
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ia64_fc((void *) ip);
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++offp;
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}
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ia64_sync_i();
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ia64_srlz_i();
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}
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void __init
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ia64_patch_gate (void)
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{
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# define START(name) ((unsigned long) __start_gate_##name##_patchlist)
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# define END(name) ((unsigned long)__end_gate_##name##_patchlist)
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patch_fsyscall_table(START(fsyscall), END(fsyscall));
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patch_brl_fsys_bubble_down(START(brl_fsys_bubble_down), END(brl_fsys_bubble_down));
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ia64_patch_vtop(START(vtop), END(vtop));
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ia64_patch_mckinley_e9(START(mckinley_e9), END(mckinley_e9));
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}
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void ia64_patch_phys_stack_reg(unsigned long val)
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{
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s32 * offp = (s32 *) __start___phys_stack_reg_patchlist;
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s32 * end = (s32 *) __end___phys_stack_reg_patchlist;
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u64 ip, mask, imm;
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/* see instruction format A4: adds r1 = imm13, r3 */
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mask = (0x3fUL << 27) | (0x7f << 13);
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imm = (((val >> 7) & 0x3f) << 27) | (val & 0x7f) << 13;
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while (offp < end) {
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ip = (u64) offp + *offp;
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ia64_patch(ip, mask, imm);
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ia64_fc(ip);
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++offp;
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}
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ia64_sync_i();
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ia64_srlz_i();
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}
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