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linux_dsm_epyc7002/arch/ia64/kernel/unaligned.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

1550 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* Architecture-specific unaligned trap handling.
*
* Copyright (C) 1999-2002, 2004 Hewlett-Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 2002/12/09 Fix rotating register handling (off-by-1 error, missing fr-rotation). Fix
* get_rse_reg() to not leak kernel bits to user-level (reading an out-of-frame
* stacked register returns an undefined value; it does NOT trigger a
* "rsvd register fault").
* 2001/10/11 Fix unaligned access to rotating registers in s/w pipelined loops.
* 2001/08/13 Correct size of extended floats (float_fsz) from 16 to 10 bytes.
* 2001/01/17 Add support emulation of unaligned kernel accesses.
*/
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/tty.h>
#include <linux/extable.h>
#include <linux/ratelimit.h>
#include <linux/uaccess.h>
#include <asm/intrinsics.h>
#include <asm/processor.h>
#include <asm/rse.h>
#include <asm/exception.h>
#include <asm/unaligned.h>
extern int die_if_kernel(char *str, struct pt_regs *regs, long err);
#undef DEBUG_UNALIGNED_TRAP
#ifdef DEBUG_UNALIGNED_TRAP
# define DPRINT(a...) do { printk("%s %u: ", __func__, __LINE__); printk (a); } while (0)
# define DDUMP(str,vp,len) dump(str, vp, len)
static void
dump (const char *str, void *vp, size_t len)
{
unsigned char *cp = vp;
int i;
printk("%s", str);
for (i = 0; i < len; ++i)
printk (" %02x", *cp++);
printk("\n");
}
#else
# define DPRINT(a...)
# define DDUMP(str,vp,len)
#endif
#define IA64_FIRST_STACKED_GR 32
#define IA64_FIRST_ROTATING_FR 32
#define SIGN_EXT9 0xffffffffffffff00ul
/*
* sysctl settable hook which tells the kernel whether to honor the
* IA64_THREAD_UAC_NOPRINT prctl. Because this is user settable, we want
* to allow the super user to enable/disable this for security reasons
* (i.e. don't allow attacker to fill up logs with unaligned accesses).
*/
int no_unaligned_warning;
int unaligned_dump_stack;
/*
* For M-unit:
*
* opcode | m | x6 |
* --------|------|---------|
* [40-37] | [36] | [35:30] |
* --------|------|---------|
* 4 | 1 | 6 | = 11 bits
* --------------------------
* However bits [31:30] are not directly useful to distinguish between
* load/store so we can use [35:32] instead, which gives the following
* mask ([40:32]) using 9 bits. The 'e' comes from the fact that we defer
* checking the m-bit until later in the load/store emulation.
*/
#define IA64_OPCODE_MASK 0x1ef
#define IA64_OPCODE_SHIFT 32
/*
* Table C-28 Integer Load/Store
*
* We ignore [35:32]= 0x6, 0x7, 0xE, 0xF
*
* ld8.fill, st8.fill MUST be aligned because the RNATs are based on
* the address (bits [8:3]), so we must failed.
*/
#define LD_OP 0x080
#define LDS_OP 0x081
#define LDA_OP 0x082
#define LDSA_OP 0x083
#define LDBIAS_OP 0x084
#define LDACQ_OP 0x085
/* 0x086, 0x087 are not relevant */
#define LDCCLR_OP 0x088
#define LDCNC_OP 0x089
#define LDCCLRACQ_OP 0x08a
#define ST_OP 0x08c
#define STREL_OP 0x08d
/* 0x08e,0x8f are not relevant */
/*
* Table C-29 Integer Load +Reg
*
* we use the ld->m (bit [36:36]) field to determine whether or not we have
* a load/store of this form.
*/
/*
* Table C-30 Integer Load/Store +Imm
*
* We ignore [35:32]= 0x6, 0x7, 0xE, 0xF
*
* ld8.fill, st8.fill must be aligned because the Nat register are based on
* the address, so we must fail and the program must be fixed.
*/
#define LD_IMM_OP 0x0a0
#define LDS_IMM_OP 0x0a1
#define LDA_IMM_OP 0x0a2
#define LDSA_IMM_OP 0x0a3
#define LDBIAS_IMM_OP 0x0a4
#define LDACQ_IMM_OP 0x0a5
/* 0x0a6, 0xa7 are not relevant */
#define LDCCLR_IMM_OP 0x0a8
#define LDCNC_IMM_OP 0x0a9
#define LDCCLRACQ_IMM_OP 0x0aa
#define ST_IMM_OP 0x0ac
#define STREL_IMM_OP 0x0ad
/* 0x0ae,0xaf are not relevant */
/*
* Table C-32 Floating-point Load/Store
*/
#define LDF_OP 0x0c0
#define LDFS_OP 0x0c1
#define LDFA_OP 0x0c2
#define LDFSA_OP 0x0c3
/* 0x0c6 is irrelevant */
#define LDFCCLR_OP 0x0c8
#define LDFCNC_OP 0x0c9
/* 0x0cb is irrelevant */
#define STF_OP 0x0cc
/*
* Table C-33 Floating-point Load +Reg
*
* we use the ld->m (bit [36:36]) field to determine whether or not we have
* a load/store of this form.
*/
/*
* Table C-34 Floating-point Load/Store +Imm
*/
#define LDF_IMM_OP 0x0e0
#define LDFS_IMM_OP 0x0e1
#define LDFA_IMM_OP 0x0e2
#define LDFSA_IMM_OP 0x0e3
/* 0x0e6 is irrelevant */
#define LDFCCLR_IMM_OP 0x0e8
#define LDFCNC_IMM_OP 0x0e9
#define STF_IMM_OP 0x0ec
typedef struct {
unsigned long qp:6; /* [0:5] */
unsigned long r1:7; /* [6:12] */
unsigned long imm:7; /* [13:19] */
unsigned long r3:7; /* [20:26] */
unsigned long x:1; /* [27:27] */
unsigned long hint:2; /* [28:29] */
unsigned long x6_sz:2; /* [30:31] */
unsigned long x6_op:4; /* [32:35], x6 = x6_sz|x6_op */
unsigned long m:1; /* [36:36] */
unsigned long op:4; /* [37:40] */
unsigned long pad:23; /* [41:63] */
} load_store_t;
typedef enum {
UPD_IMMEDIATE, /* ldXZ r1=[r3],imm(9) */
UPD_REG /* ldXZ r1=[r3],r2 */
} update_t;
/*
* We use tables to keep track of the offsets of registers in the saved state.
* This way we save having big switch/case statements.
*
* We use bit 0 to indicate switch_stack or pt_regs.
* The offset is simply shifted by 1 bit.
* A 2-byte value should be enough to hold any kind of offset
*
* In case the calling convention changes (and thus pt_regs/switch_stack)
* simply use RSW instead of RPT or vice-versa.
*/
#define RPO(x) ((size_t) &((struct pt_regs *)0)->x)
#define RSO(x) ((size_t) &((struct switch_stack *)0)->x)
#define RPT(x) (RPO(x) << 1)
#define RSW(x) (1| RSO(x)<<1)
#define GR_OFFS(x) (gr_info[x]>>1)
#define GR_IN_SW(x) (gr_info[x] & 0x1)
#define FR_OFFS(x) (fr_info[x]>>1)
#define FR_IN_SW(x) (fr_info[x] & 0x1)
static u16 gr_info[32]={
0, /* r0 is read-only : WE SHOULD NEVER GET THIS */
RPT(r1), RPT(r2), RPT(r3),
RSW(r4), RSW(r5), RSW(r6), RSW(r7),
RPT(r8), RPT(r9), RPT(r10), RPT(r11),
RPT(r12), RPT(r13), RPT(r14), RPT(r15),
RPT(r16), RPT(r17), RPT(r18), RPT(r19),
RPT(r20), RPT(r21), RPT(r22), RPT(r23),
RPT(r24), RPT(r25), RPT(r26), RPT(r27),
RPT(r28), RPT(r29), RPT(r30), RPT(r31)
};
static u16 fr_info[32]={
0, /* constant : WE SHOULD NEVER GET THIS */
0, /* constant : WE SHOULD NEVER GET THIS */
RSW(f2), RSW(f3), RSW(f4), RSW(f5),
RPT(f6), RPT(f7), RPT(f8), RPT(f9),
RPT(f10), RPT(f11),
RSW(f12), RSW(f13), RSW(f14),
RSW(f15), RSW(f16), RSW(f17), RSW(f18), RSW(f19),
RSW(f20), RSW(f21), RSW(f22), RSW(f23), RSW(f24),
RSW(f25), RSW(f26), RSW(f27), RSW(f28), RSW(f29),
RSW(f30), RSW(f31)
};
/* Invalidate ALAT entry for integer register REGNO. */
static void
invala_gr (int regno)
{
# define F(reg) case reg: ia64_invala_gr(reg); break
switch (regno) {
F( 0); F( 1); F( 2); F( 3); F( 4); F( 5); F( 6); F( 7);
F( 8); F( 9); F( 10); F( 11); F( 12); F( 13); F( 14); F( 15);
F( 16); F( 17); F( 18); F( 19); F( 20); F( 21); F( 22); F( 23);
F( 24); F( 25); F( 26); F( 27); F( 28); F( 29); F( 30); F( 31);
F( 32); F( 33); F( 34); F( 35); F( 36); F( 37); F( 38); F( 39);
F( 40); F( 41); F( 42); F( 43); F( 44); F( 45); F( 46); F( 47);
F( 48); F( 49); F( 50); F( 51); F( 52); F( 53); F( 54); F( 55);
F( 56); F( 57); F( 58); F( 59); F( 60); F( 61); F( 62); F( 63);
F( 64); F( 65); F( 66); F( 67); F( 68); F( 69); F( 70); F( 71);
F( 72); F( 73); F( 74); F( 75); F( 76); F( 77); F( 78); F( 79);
F( 80); F( 81); F( 82); F( 83); F( 84); F( 85); F( 86); F( 87);
F( 88); F( 89); F( 90); F( 91); F( 92); F( 93); F( 94); F( 95);
F( 96); F( 97); F( 98); F( 99); F(100); F(101); F(102); F(103);
F(104); F(105); F(106); F(107); F(108); F(109); F(110); F(111);
F(112); F(113); F(114); F(115); F(116); F(117); F(118); F(119);
F(120); F(121); F(122); F(123); F(124); F(125); F(126); F(127);
}
# undef F
}
/* Invalidate ALAT entry for floating-point register REGNO. */
static void
invala_fr (int regno)
{
# define F(reg) case reg: ia64_invala_fr(reg); break
switch (regno) {
F( 0); F( 1); F( 2); F( 3); F( 4); F( 5); F( 6); F( 7);
F( 8); F( 9); F( 10); F( 11); F( 12); F( 13); F( 14); F( 15);
F( 16); F( 17); F( 18); F( 19); F( 20); F( 21); F( 22); F( 23);
F( 24); F( 25); F( 26); F( 27); F( 28); F( 29); F( 30); F( 31);
F( 32); F( 33); F( 34); F( 35); F( 36); F( 37); F( 38); F( 39);
F( 40); F( 41); F( 42); F( 43); F( 44); F( 45); F( 46); F( 47);
F( 48); F( 49); F( 50); F( 51); F( 52); F( 53); F( 54); F( 55);
F( 56); F( 57); F( 58); F( 59); F( 60); F( 61); F( 62); F( 63);
F( 64); F( 65); F( 66); F( 67); F( 68); F( 69); F( 70); F( 71);
F( 72); F( 73); F( 74); F( 75); F( 76); F( 77); F( 78); F( 79);
F( 80); F( 81); F( 82); F( 83); F( 84); F( 85); F( 86); F( 87);
F( 88); F( 89); F( 90); F( 91); F( 92); F( 93); F( 94); F( 95);
F( 96); F( 97); F( 98); F( 99); F(100); F(101); F(102); F(103);
F(104); F(105); F(106); F(107); F(108); F(109); F(110); F(111);
F(112); F(113); F(114); F(115); F(116); F(117); F(118); F(119);
F(120); F(121); F(122); F(123); F(124); F(125); F(126); F(127);
}
# undef F
}
static inline unsigned long
rotate_reg (unsigned long sor, unsigned long rrb, unsigned long reg)
{
reg += rrb;
if (reg >= sor)
reg -= sor;
return reg;
}
static void
set_rse_reg (struct pt_regs *regs, unsigned long r1, unsigned long val, int nat)
{
struct switch_stack *sw = (struct switch_stack *) regs - 1;
unsigned long *bsp, *bspstore, *addr, *rnat_addr, *ubs_end;
unsigned long *kbs = (void *) current + IA64_RBS_OFFSET;
unsigned long rnats, nat_mask;
unsigned long on_kbs;
long sof = (regs->cr_ifs) & 0x7f;
long sor = 8 * ((regs->cr_ifs >> 14) & 0xf);
long rrb_gr = (regs->cr_ifs >> 18) & 0x7f;
long ridx = r1 - 32;
if (ridx >= sof) {
/* this should never happen, as the "rsvd register fault" has higher priority */
DPRINT("ignoring write to r%lu; only %lu registers are allocated!\n", r1, sof);
return;
}
if (ridx < sor)
ridx = rotate_reg(sor, rrb_gr, ridx);
DPRINT("r%lu, sw.bspstore=%lx pt.bspstore=%lx sof=%ld sol=%ld ridx=%ld\n",
r1, sw->ar_bspstore, regs->ar_bspstore, sof, (regs->cr_ifs >> 7) & 0x7f, ridx);
on_kbs = ia64_rse_num_regs(kbs, (unsigned long *) sw->ar_bspstore);
addr = ia64_rse_skip_regs((unsigned long *) sw->ar_bspstore, -sof + ridx);
if (addr >= kbs) {
/* the register is on the kernel backing store: easy... */
rnat_addr = ia64_rse_rnat_addr(addr);
if ((unsigned long) rnat_addr >= sw->ar_bspstore)
rnat_addr = &sw->ar_rnat;
nat_mask = 1UL << ia64_rse_slot_num(addr);
*addr = val;
if (nat)
*rnat_addr |= nat_mask;
else
*rnat_addr &= ~nat_mask;
return;
}
if (!user_stack(current, regs)) {
DPRINT("ignoring kernel write to r%lu; register isn't on the kernel RBS!", r1);
return;
}
bspstore = (unsigned long *)regs->ar_bspstore;
ubs_end = ia64_rse_skip_regs(bspstore, on_kbs);
bsp = ia64_rse_skip_regs(ubs_end, -sof);
addr = ia64_rse_skip_regs(bsp, ridx);
DPRINT("ubs_end=%p bsp=%p addr=%p\n", (void *) ubs_end, (void *) bsp, (void *) addr);
ia64_poke(current, sw, (unsigned long) ubs_end, (unsigned long) addr, val);
rnat_addr = ia64_rse_rnat_addr(addr);
ia64_peek(current, sw, (unsigned long) ubs_end, (unsigned long) rnat_addr, &rnats);
DPRINT("rnat @%p = 0x%lx nat=%d old nat=%ld\n",
(void *) rnat_addr, rnats, nat, (rnats >> ia64_rse_slot_num(addr)) & 1);
nat_mask = 1UL << ia64_rse_slot_num(addr);
if (nat)
rnats |= nat_mask;
else
rnats &= ~nat_mask;
ia64_poke(current, sw, (unsigned long) ubs_end, (unsigned long) rnat_addr, rnats);
DPRINT("rnat changed to @%p = 0x%lx\n", (void *) rnat_addr, rnats);
}
static void
get_rse_reg (struct pt_regs *regs, unsigned long r1, unsigned long *val, int *nat)
{
struct switch_stack *sw = (struct switch_stack *) regs - 1;
unsigned long *bsp, *addr, *rnat_addr, *ubs_end, *bspstore;
unsigned long *kbs = (void *) current + IA64_RBS_OFFSET;
unsigned long rnats, nat_mask;
unsigned long on_kbs;
long sof = (regs->cr_ifs) & 0x7f;
long sor = 8 * ((regs->cr_ifs >> 14) & 0xf);
long rrb_gr = (regs->cr_ifs >> 18) & 0x7f;
long ridx = r1 - 32;
if (ridx >= sof) {
/* read of out-of-frame register returns an undefined value; 0 in our case. */
DPRINT("ignoring read from r%lu; only %lu registers are allocated!\n", r1, sof);
goto fail;
}
if (ridx < sor)
ridx = rotate_reg(sor, rrb_gr, ridx);
DPRINT("r%lu, sw.bspstore=%lx pt.bspstore=%lx sof=%ld sol=%ld ridx=%ld\n",
r1, sw->ar_bspstore, regs->ar_bspstore, sof, (regs->cr_ifs >> 7) & 0x7f, ridx);
on_kbs = ia64_rse_num_regs(kbs, (unsigned long *) sw->ar_bspstore);
addr = ia64_rse_skip_regs((unsigned long *) sw->ar_bspstore, -sof + ridx);
if (addr >= kbs) {
/* the register is on the kernel backing store: easy... */
*val = *addr;
if (nat) {
rnat_addr = ia64_rse_rnat_addr(addr);
if ((unsigned long) rnat_addr >= sw->ar_bspstore)
rnat_addr = &sw->ar_rnat;
nat_mask = 1UL << ia64_rse_slot_num(addr);
*nat = (*rnat_addr & nat_mask) != 0;
}
return;
}
if (!user_stack(current, regs)) {
DPRINT("ignoring kernel read of r%lu; register isn't on the RBS!", r1);
goto fail;
}
bspstore = (unsigned long *)regs->ar_bspstore;
ubs_end = ia64_rse_skip_regs(bspstore, on_kbs);
bsp = ia64_rse_skip_regs(ubs_end, -sof);
addr = ia64_rse_skip_regs(bsp, ridx);
DPRINT("ubs_end=%p bsp=%p addr=%p\n", (void *) ubs_end, (void *) bsp, (void *) addr);
ia64_peek(current, sw, (unsigned long) ubs_end, (unsigned long) addr, val);
if (nat) {
rnat_addr = ia64_rse_rnat_addr(addr);
nat_mask = 1UL << ia64_rse_slot_num(addr);
DPRINT("rnat @%p = 0x%lx\n", (void *) rnat_addr, rnats);
ia64_peek(current, sw, (unsigned long) ubs_end, (unsigned long) rnat_addr, &rnats);
*nat = (rnats & nat_mask) != 0;
}
return;
fail:
*val = 0;
if (nat)
*nat = 0;
return;
}
static void
setreg (unsigned long regnum, unsigned long val, int nat, struct pt_regs *regs)
{
struct switch_stack *sw = (struct switch_stack *) regs - 1;
unsigned long addr;
unsigned long bitmask;
unsigned long *unat;
/*
* First takes care of stacked registers
*/
if (regnum >= IA64_FIRST_STACKED_GR) {
set_rse_reg(regs, regnum, val, nat);
return;
}
/*
* Using r0 as a target raises a General Exception fault which has higher priority
* than the Unaligned Reference fault.
*/
/*
* Now look at registers in [0-31] range and init correct UNAT
*/
if (GR_IN_SW(regnum)) {
addr = (unsigned long)sw;
unat = &sw->ar_unat;
} else {
addr = (unsigned long)regs;
unat = &sw->caller_unat;
}
DPRINT("tmp_base=%lx switch_stack=%s offset=%d\n",
addr, unat==&sw->ar_unat ? "yes":"no", GR_OFFS(regnum));
/*
* add offset from base of struct
* and do it !
*/
addr += GR_OFFS(regnum);
*(unsigned long *)addr = val;
/*
* We need to clear the corresponding UNAT bit to fully emulate the load
* UNAT bit_pos = GR[r3]{8:3} form EAS-2.4
*/
bitmask = 1UL << (addr >> 3 & 0x3f);
DPRINT("*0x%lx=0x%lx NaT=%d prev_unat @%p=%lx\n", addr, val, nat, (void *) unat, *unat);
if (nat) {
*unat |= bitmask;
} else {
*unat &= ~bitmask;
}
DPRINT("*0x%lx=0x%lx NaT=%d new unat: %p=%lx\n", addr, val, nat, (void *) unat,*unat);
}
/*
* Return the (rotated) index for floating point register REGNUM (REGNUM must be in the
* range from 32-127, result is in the range from 0-95.
*/
static inline unsigned long
fph_index (struct pt_regs *regs, long regnum)
{
unsigned long rrb_fr = (regs->cr_ifs >> 25) & 0x7f;
return rotate_reg(96, rrb_fr, (regnum - IA64_FIRST_ROTATING_FR));
}
static void
setfpreg (unsigned long regnum, struct ia64_fpreg *fpval, struct pt_regs *regs)
{
struct switch_stack *sw = (struct switch_stack *)regs - 1;
unsigned long addr;
/*
* From EAS-2.5: FPDisableFault has higher priority than Unaligned
* Fault. Thus, when we get here, we know the partition is enabled.
* To update f32-f127, there are three choices:
*
* (1) save f32-f127 to thread.fph and update the values there
* (2) use a gigantic switch statement to directly access the registers
* (3) generate code on the fly to update the desired register
*
* For now, we are using approach (1).
*/
if (regnum >= IA64_FIRST_ROTATING_FR) {
ia64_sync_fph(current);
current->thread.fph[fph_index(regs, regnum)] = *fpval;
} else {
/*
* pt_regs or switch_stack ?
*/
if (FR_IN_SW(regnum)) {
addr = (unsigned long)sw;
} else {
addr = (unsigned long)regs;
}
DPRINT("tmp_base=%lx offset=%d\n", addr, FR_OFFS(regnum));
addr += FR_OFFS(regnum);
*(struct ia64_fpreg *)addr = *fpval;
/*
* mark the low partition as being used now
*
* It is highly unlikely that this bit is not already set, but
* let's do it for safety.
*/
regs->cr_ipsr |= IA64_PSR_MFL;
}
}
/*
* Those 2 inline functions generate the spilled versions of the constant floating point
* registers which can be used with stfX
*/
static inline void
float_spill_f0 (struct ia64_fpreg *final)
{
ia64_stf_spill(final, 0);
}
static inline void
float_spill_f1 (struct ia64_fpreg *final)
{
ia64_stf_spill(final, 1);
}
static void
getfpreg (unsigned long regnum, struct ia64_fpreg *fpval, struct pt_regs *regs)
{
struct switch_stack *sw = (struct switch_stack *) regs - 1;
unsigned long addr;
/*
* From EAS-2.5: FPDisableFault has higher priority than
* Unaligned Fault. Thus, when we get here, we know the partition is
* enabled.
*
* When regnum > 31, the register is still live and we need to force a save
* to current->thread.fph to get access to it. See discussion in setfpreg()
* for reasons and other ways of doing this.
*/
if (regnum >= IA64_FIRST_ROTATING_FR) {
ia64_flush_fph(current);
*fpval = current->thread.fph[fph_index(regs, regnum)];
} else {
/*
* f0 = 0.0, f1= 1.0. Those registers are constant and are thus
* not saved, we must generate their spilled form on the fly
*/
switch(regnum) {
case 0:
float_spill_f0(fpval);
break;
case 1:
float_spill_f1(fpval);
break;
default:
/*
* pt_regs or switch_stack ?
*/
addr = FR_IN_SW(regnum) ? (unsigned long)sw
: (unsigned long)regs;
DPRINT("is_sw=%d tmp_base=%lx offset=0x%x\n",
FR_IN_SW(regnum), addr, FR_OFFS(regnum));
addr += FR_OFFS(regnum);
*fpval = *(struct ia64_fpreg *)addr;
}
}
}
static void
getreg (unsigned long regnum, unsigned long *val, int *nat, struct pt_regs *regs)
{
struct switch_stack *sw = (struct switch_stack *) regs - 1;
unsigned long addr, *unat;
if (regnum >= IA64_FIRST_STACKED_GR) {
get_rse_reg(regs, regnum, val, nat);
return;
}
/*
* take care of r0 (read-only always evaluate to 0)
*/
if (regnum == 0) {
*val = 0;
if (nat)
*nat = 0;
return;
}
/*
* Now look at registers in [0-31] range and init correct UNAT
*/
if (GR_IN_SW(regnum)) {
addr = (unsigned long)sw;
unat = &sw->ar_unat;
} else {
addr = (unsigned long)regs;
unat = &sw->caller_unat;
}
DPRINT("addr_base=%lx offset=0x%x\n", addr, GR_OFFS(regnum));
addr += GR_OFFS(regnum);
*val = *(unsigned long *)addr;
/*
* do it only when requested
*/
if (nat)
*nat = (*unat >> (addr >> 3 & 0x3f)) & 0x1UL;
}
static void
emulate_load_updates (update_t type, load_store_t ld, struct pt_regs *regs, unsigned long ifa)
{
/*
* IMPORTANT:
* Given the way we handle unaligned speculative loads, we should
* not get to this point in the code but we keep this sanity check,
* just in case.
*/
if (ld.x6_op == 1 || ld.x6_op == 3) {
printk(KERN_ERR "%s: register update on speculative load, error\n", __func__);
if (die_if_kernel("unaligned reference on speculative load with register update\n",
regs, 30))
return;
}
/*
* at this point, we know that the base register to update is valid i.e.,
* it's not r0
*/
if (type == UPD_IMMEDIATE) {
unsigned long imm;
/*
* Load +Imm: ldXZ r1=[r3],imm(9)
*
*
* form imm9: [13:19] contain the first 7 bits
*/
imm = ld.x << 7 | ld.imm;
/*
* sign extend (1+8bits) if m set
*/
if (ld.m) imm |= SIGN_EXT9;
/*
* ifa == r3 and we know that the NaT bit on r3 was clear so
* we can directly use ifa.
*/
ifa += imm;
setreg(ld.r3, ifa, 0, regs);
DPRINT("ld.x=%d ld.m=%d imm=%ld r3=0x%lx\n", ld.x, ld.m, imm, ifa);
} else if (ld.m) {
unsigned long r2;
int nat_r2;
/*
* Load +Reg Opcode: ldXZ r1=[r3],r2
*
* Note: that we update r3 even in the case of ldfX.a
* (where the load does not happen)
*
* The way the load algorithm works, we know that r3 does not
* have its NaT bit set (would have gotten NaT consumption
* before getting the unaligned fault). So we can use ifa
* which equals r3 at this point.
*
* IMPORTANT:
* The above statement holds ONLY because we know that we
* never reach this code when trying to do a ldX.s.
* If we ever make it to here on an ldfX.s then
*/
getreg(ld.imm, &r2, &nat_r2, regs);
ifa += r2;
/*
* propagate Nat r2 -> r3
*/
setreg(ld.r3, ifa, nat_r2, regs);
DPRINT("imm=%d r2=%ld r3=0x%lx nat_r2=%d\n",ld.imm, r2, ifa, nat_r2);
}
}
static int
emulate_load_int (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
{
unsigned int len = 1 << ld.x6_sz;
unsigned long val = 0;
/*
* r0, as target, doesn't need to be checked because Illegal Instruction
* faults have higher priority than unaligned faults.
*
* r0 cannot be found as the base as it would never generate an
* unaligned reference.
*/
/*
* ldX.a we will emulate load and also invalidate the ALAT entry.
* See comment below for explanation on how we handle ldX.a
*/
if (len != 2 && len != 4 && len != 8) {
DPRINT("unknown size: x6=%d\n", ld.x6_sz);
return -1;
}
/* this assumes little-endian byte-order: */
if (copy_from_user(&val, (void __user *) ifa, len))
return -1;
setreg(ld.r1, val, 0, regs);
/*
* check for updates on any kind of loads
*/
if (ld.op == 0x5 || ld.m)
emulate_load_updates(ld.op == 0x5 ? UPD_IMMEDIATE: UPD_REG, ld, regs, ifa);
/*
* handling of various loads (based on EAS2.4):
*
* ldX.acq (ordered load):
* - acquire semantics would have been used, so force fence instead.
*
* ldX.c.clr (check load and clear):
* - if we get to this handler, it's because the entry was not in the ALAT.
* Therefore the operation reverts to a normal load
*
* ldX.c.nc (check load no clear):
* - same as previous one
*
* ldX.c.clr.acq (ordered check load and clear):
* - same as above for c.clr part. The load needs to have acquire semantics. So
* we use the fence semantics which is stronger and thus ensures correctness.
*
* ldX.a (advanced load):
* - suppose ldX.a r1=[r3]. If we get to the unaligned trap it's because the
* address doesn't match requested size alignment. This means that we would
* possibly need more than one load to get the result.
*
* The load part can be handled just like a normal load, however the difficult
* part is to get the right thing into the ALAT. The critical piece of information
* in the base address of the load & size. To do that, a ld.a must be executed,
* clearly any address can be pushed into the table by using ld1.a r1=[r3]. Now
* if we use the same target register, we will be okay for the check.a instruction.
* If we look at the store, basically a stX [r3]=r1 checks the ALAT for any entry
* which would overlap within [r3,r3+X] (the size of the load was store in the
* ALAT). If such an entry is found the entry is invalidated. But this is not good
* enough, take the following example:
* r3=3
* ld4.a r1=[r3]
*
* Could be emulated by doing:
* ld1.a r1=[r3],1
* store to temporary;
* ld1.a r1=[r3],1
* store & shift to temporary;
* ld1.a r1=[r3],1
* store & shift to temporary;
* ld1.a r1=[r3]
* store & shift to temporary;
* r1=temporary
*
* So in this case, you would get the right value is r1 but the wrong info in
* the ALAT. Notice that you could do it in reverse to finish with address 3
* but you would still get the size wrong. To get the size right, one needs to
* execute exactly the same kind of load. You could do it from a aligned
* temporary location, but you would get the address wrong.
*
* So no matter what, it is not possible to emulate an advanced load
* correctly. But is that really critical ?
*
* We will always convert ld.a into a normal load with ALAT invalidated. This
* will enable compiler to do optimization where certain code path after ld.a
* is not required to have ld.c/chk.a, e.g., code path with no intervening stores.
*
* If there is a store after the advanced load, one must either do a ld.c.* or
* chk.a.* to reuse the value stored in the ALAT. Both can "fail" (meaning no
* entry found in ALAT), and that's perfectly ok because:
*
* - ld.c.*, if the entry is not present a normal load is executed
* - chk.a.*, if the entry is not present, execution jumps to recovery code
*
* In either case, the load can be potentially retried in another form.
*
* ALAT must be invalidated for the register (so that chk.a or ld.c don't pick
* up a stale entry later). The register base update MUST also be performed.
*/
/*
* when the load has the .acq completer then
* use ordering fence.
*/
if (ld.x6_op == 0x5 || ld.x6_op == 0xa)
mb();
/*
* invalidate ALAT entry in case of advanced load
*/
if (ld.x6_op == 0x2)
invala_gr(ld.r1);
return 0;
}
static int
emulate_store_int (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
{
unsigned long r2;
unsigned int len = 1 << ld.x6_sz;
/*
* if we get to this handler, Nat bits on both r3 and r2 have already
* been checked. so we don't need to do it
*
* extract the value to be stored
*/
getreg(ld.imm, &r2, NULL, regs);
/*
* we rely on the macros in unaligned.h for now i.e.,
* we let the compiler figure out how to read memory gracefully.
*
* We need this switch/case because the way the inline function
* works. The code is optimized by the compiler and looks like
* a single switch/case.
*/
DPRINT("st%d [%lx]=%lx\n", len, ifa, r2);
if (len != 2 && len != 4 && len != 8) {
DPRINT("unknown size: x6=%d\n", ld.x6_sz);
return -1;
}
/* this assumes little-endian byte-order: */
if (copy_to_user((void __user *) ifa, &r2, len))
return -1;
/*
* stX [r3]=r2,imm(9)
*
* NOTE:
* ld.r3 can never be r0, because r0 would not generate an
* unaligned access.
*/
if (ld.op == 0x5) {
unsigned long imm;
/*
* form imm9: [12:6] contain first 7bits
*/
imm = ld.x << 7 | ld.r1;
/*
* sign extend (8bits) if m set
*/
if (ld.m) imm |= SIGN_EXT9;
/*
* ifa == r3 (NaT is necessarily cleared)
*/
ifa += imm;
DPRINT("imm=%lx r3=%lx\n", imm, ifa);
setreg(ld.r3, ifa, 0, regs);
}
/*
* we don't have alat_invalidate_multiple() so we need
* to do the complete flush :-<<
*/
ia64_invala();
/*
* stX.rel: use fence instead of release
*/
if (ld.x6_op == 0xd)
mb();
return 0;
}
/*
* floating point operations sizes in bytes
*/
static const unsigned char float_fsz[4]={
10, /* extended precision (e) */
8, /* integer (8) */
4, /* single precision (s) */
8 /* double precision (d) */
};
static inline void
mem2float_extended (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldfe(6, init);
ia64_stop();
ia64_stf_spill(final, 6);
}
static inline void
mem2float_integer (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldf8(6, init);
ia64_stop();
ia64_stf_spill(final, 6);
}
static inline void
mem2float_single (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldfs(6, init);
ia64_stop();
ia64_stf_spill(final, 6);
}
static inline void
mem2float_double (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldfd(6, init);
ia64_stop();
ia64_stf_spill(final, 6);
}
static inline void
float2mem_extended (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldf_fill(6, init);
ia64_stop();
ia64_stfe(final, 6);
}
static inline void
float2mem_integer (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldf_fill(6, init);
ia64_stop();
ia64_stf8(final, 6);
}
static inline void
float2mem_single (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldf_fill(6, init);
ia64_stop();
ia64_stfs(final, 6);
}
static inline void
float2mem_double (struct ia64_fpreg *init, struct ia64_fpreg *final)
{
ia64_ldf_fill(6, init);
ia64_stop();
ia64_stfd(final, 6);
}
static int
emulate_load_floatpair (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
{
struct ia64_fpreg fpr_init[2];
struct ia64_fpreg fpr_final[2];
unsigned long len = float_fsz[ld.x6_sz];
/*
* fr0 & fr1 don't need to be checked because Illegal Instruction faults have
* higher priority than unaligned faults.
*
* r0 cannot be found as the base as it would never generate an unaligned
* reference.
*/
/*
* make sure we get clean buffers
*/
memset(&fpr_init, 0, sizeof(fpr_init));
memset(&fpr_final, 0, sizeof(fpr_final));
/*
* ldfpX.a: we don't try to emulate anything but we must
* invalidate the ALAT entry and execute updates, if any.
*/
if (ld.x6_op != 0x2) {
/*
* This assumes little-endian byte-order. Note that there is no "ldfpe"
* instruction:
*/
if (copy_from_user(&fpr_init[0], (void __user *) ifa, len)
|| copy_from_user(&fpr_init[1], (void __user *) (ifa + len), len))
return -1;
DPRINT("ld.r1=%d ld.imm=%d x6_sz=%d\n", ld.r1, ld.imm, ld.x6_sz);
DDUMP("frp_init =", &fpr_init, 2*len);
/*
* XXX fixme
* Could optimize inlines by using ldfpX & 2 spills
*/
switch( ld.x6_sz ) {
case 0:
mem2float_extended(&fpr_init[0], &fpr_final[0]);
mem2float_extended(&fpr_init[1], &fpr_final[1]);
break;
case 1:
mem2float_integer(&fpr_init[0], &fpr_final[0]);
mem2float_integer(&fpr_init[1], &fpr_final[1]);
break;
case 2:
mem2float_single(&fpr_init[0], &fpr_final[0]);
mem2float_single(&fpr_init[1], &fpr_final[1]);
break;
case 3:
mem2float_double(&fpr_init[0], &fpr_final[0]);
mem2float_double(&fpr_init[1], &fpr_final[1]);
break;
}
DDUMP("fpr_final =", &fpr_final, 2*len);
/*
* XXX fixme
*
* A possible optimization would be to drop fpr_final and directly
* use the storage from the saved context i.e., the actual final
* destination (pt_regs, switch_stack or thread structure).
*/
setfpreg(ld.r1, &fpr_final[0], regs);
setfpreg(ld.imm, &fpr_final[1], regs);
}
/*
* Check for updates: only immediate updates are available for this
* instruction.
*/
if (ld.m) {
/*
* the immediate is implicit given the ldsz of the operation:
* single: 8 (2x4) and for all others it's 16 (2x8)
*/
ifa += len<<1;
/*
* IMPORTANT:
* the fact that we force the NaT of r3 to zero is ONLY valid
* as long as we don't come here with a ldfpX.s.
* For this reason we keep this sanity check
*/
if (ld.x6_op == 1 || ld.x6_op == 3)
printk(KERN_ERR "%s: register update on speculative load pair, error\n",
__func__);
setreg(ld.r3, ifa, 0, regs);
}
/*
* Invalidate ALAT entries, if any, for both registers.
*/
if (ld.x6_op == 0x2) {
invala_fr(ld.r1);
invala_fr(ld.imm);
}
return 0;
}
static int
emulate_load_float (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
{
struct ia64_fpreg fpr_init;
struct ia64_fpreg fpr_final;
unsigned long len = float_fsz[ld.x6_sz];
/*
* fr0 & fr1 don't need to be checked because Illegal Instruction
* faults have higher priority than unaligned faults.
*
* r0 cannot be found as the base as it would never generate an
* unaligned reference.
*/
/*
* make sure we get clean buffers
*/
memset(&fpr_init,0, sizeof(fpr_init));
memset(&fpr_final,0, sizeof(fpr_final));
/*
* ldfX.a we don't try to emulate anything but we must
* invalidate the ALAT entry.
* See comments in ldX for descriptions on how the various loads are handled.
*/
if (ld.x6_op != 0x2) {
if (copy_from_user(&fpr_init, (void __user *) ifa, len))
return -1;
DPRINT("ld.r1=%d x6_sz=%d\n", ld.r1, ld.x6_sz);
DDUMP("fpr_init =", &fpr_init, len);
/*
* we only do something for x6_op={0,8,9}
*/
switch( ld.x6_sz ) {
case 0:
mem2float_extended(&fpr_init, &fpr_final);
break;
case 1:
mem2float_integer(&fpr_init, &fpr_final);
break;
case 2:
mem2float_single(&fpr_init, &fpr_final);
break;
case 3:
mem2float_double(&fpr_init, &fpr_final);
break;
}
DDUMP("fpr_final =", &fpr_final, len);
/*
* XXX fixme
*
* A possible optimization would be to drop fpr_final and directly
* use the storage from the saved context i.e., the actual final
* destination (pt_regs, switch_stack or thread structure).
*/
setfpreg(ld.r1, &fpr_final, regs);
}
/*
* check for updates on any loads
*/
if (ld.op == 0x7 || ld.m)
emulate_load_updates(ld.op == 0x7 ? UPD_IMMEDIATE: UPD_REG, ld, regs, ifa);
/*
* invalidate ALAT entry in case of advanced floating point loads
*/
if (ld.x6_op == 0x2)
invala_fr(ld.r1);
return 0;
}
static int
emulate_store_float (unsigned long ifa, load_store_t ld, struct pt_regs *regs)
{
struct ia64_fpreg fpr_init;
struct ia64_fpreg fpr_final;
unsigned long len = float_fsz[ld.x6_sz];
/*
* make sure we get clean buffers
*/
memset(&fpr_init,0, sizeof(fpr_init));
memset(&fpr_final,0, sizeof(fpr_final));
/*
* if we get to this handler, Nat bits on both r3 and r2 have already
* been checked. so we don't need to do it
*
* extract the value to be stored
*/
getfpreg(ld.imm, &fpr_init, regs);
/*
* during this step, we extract the spilled registers from the saved
* context i.e., we refill. Then we store (no spill) to temporary
* aligned location
*/
switch( ld.x6_sz ) {
case 0:
float2mem_extended(&fpr_init, &fpr_final);
break;
case 1:
float2mem_integer(&fpr_init, &fpr_final);
break;
case 2:
float2mem_single(&fpr_init, &fpr_final);
break;
case 3:
float2mem_double(&fpr_init, &fpr_final);
break;
}
DPRINT("ld.r1=%d x6_sz=%d\n", ld.r1, ld.x6_sz);
DDUMP("fpr_init =", &fpr_init, len);
DDUMP("fpr_final =", &fpr_final, len);
if (copy_to_user((void __user *) ifa, &fpr_final, len))
return -1;
/*
* stfX [r3]=r2,imm(9)
*
* NOTE:
* ld.r3 can never be r0, because r0 would not generate an
* unaligned access.
*/
if (ld.op == 0x7) {
unsigned long imm;
/*
* form imm9: [12:6] contain first 7bits
*/
imm = ld.x << 7 | ld.r1;
/*
* sign extend (8bits) if m set
*/
if (ld.m)
imm |= SIGN_EXT9;
/*
* ifa == r3 (NaT is necessarily cleared)
*/
ifa += imm;
DPRINT("imm=%lx r3=%lx\n", imm, ifa);
setreg(ld.r3, ifa, 0, regs);
}
/*
* we don't have alat_invalidate_multiple() so we need
* to do the complete flush :-<<
*/
ia64_invala();
return 0;
}
/*
* Make sure we log the unaligned access, so that user/sysadmin can notice it and
* eventually fix the program. However, we don't want to do that for every access so we
* pace it with jiffies.
*/
static DEFINE_RATELIMIT_STATE(logging_rate_limit, 5 * HZ, 5);
void
ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs)
{
struct ia64_psr *ipsr = ia64_psr(regs);
mm_segment_t old_fs = get_fs();
unsigned long bundle[2];
unsigned long opcode;
struct siginfo si;
const struct exception_table_entry *eh = NULL;
union {
unsigned long l;
load_store_t insn;
} u;
int ret = -1;
if (ia64_psr(regs)->be) {
/* we don't support big-endian accesses */
if (die_if_kernel("big-endian unaligned accesses are not supported", regs, 0))
return;
goto force_sigbus;
}
/*
* Treat kernel accesses for which there is an exception handler entry the same as
* user-level unaligned accesses. Otherwise, a clever program could trick this
* handler into reading an arbitrary kernel addresses...
*/
if (!user_mode(regs))
eh = search_exception_tables(regs->cr_iip + ia64_psr(regs)->ri);
if (user_mode(regs) || eh) {
if ((current->thread.flags & IA64_THREAD_UAC_SIGBUS) != 0)
goto force_sigbus;
if (!no_unaligned_warning &&
!(current->thread.flags & IA64_THREAD_UAC_NOPRINT) &&
__ratelimit(&logging_rate_limit))
{
char buf[200]; /* comm[] is at most 16 bytes... */
size_t len;
len = sprintf(buf, "%s(%d): unaligned access to 0x%016lx, "
"ip=0x%016lx\n\r", current->comm,
task_pid_nr(current),
ifa, regs->cr_iip + ipsr->ri);
/*
* Don't call tty_write_message() if we're in the kernel; we might
* be holding locks...
*/
if (user_mode(regs)) {
struct tty_struct *tty = get_current_tty();
tty_write_message(tty, buf);
tty_kref_put(tty);
}
buf[len-1] = '\0'; /* drop '\r' */
/* watch for command names containing %s */
printk(KERN_WARNING "%s", buf);
} else {
if (no_unaligned_warning) {
printk_once(KERN_WARNING "%s(%d) encountered an "
"unaligned exception which required\n"
"kernel assistance, which degrades "
"the performance of the application.\n"
"Unaligned exception warnings have "
"been disabled by the system "
"administrator\n"
"echo 0 > /proc/sys/kernel/ignore-"
"unaligned-usertrap to re-enable\n",
current->comm, task_pid_nr(current));
}
}
} else {
if (__ratelimit(&logging_rate_limit)) {
printk(KERN_WARNING "kernel unaligned access to 0x%016lx, ip=0x%016lx\n",
ifa, regs->cr_iip + ipsr->ri);
if (unaligned_dump_stack)
dump_stack();
}
set_fs(KERNEL_DS);
}
DPRINT("iip=%lx ifa=%lx isr=%lx (ei=%d, sp=%d)\n",
regs->cr_iip, ifa, regs->cr_ipsr, ipsr->ri, ipsr->it);
if (__copy_from_user(bundle, (void __user *) regs->cr_iip, 16))
goto failure;
/*
* extract the instruction from the bundle given the slot number
*/
switch (ipsr->ri) {
default:
case 0: u.l = (bundle[0] >> 5); break;
case 1: u.l = (bundle[0] >> 46) | (bundle[1] << 18); break;
case 2: u.l = (bundle[1] >> 23); break;
}
opcode = (u.l >> IA64_OPCODE_SHIFT) & IA64_OPCODE_MASK;
DPRINT("opcode=%lx ld.qp=%d ld.r1=%d ld.imm=%d ld.r3=%d ld.x=%d ld.hint=%d "
"ld.x6=0x%x ld.m=%d ld.op=%d\n", opcode, u.insn.qp, u.insn.r1, u.insn.imm,
u.insn.r3, u.insn.x, u.insn.hint, u.insn.x6_sz, u.insn.m, u.insn.op);
/*
* IMPORTANT:
* Notice that the switch statement DOES not cover all possible instructions
* that DO generate unaligned references. This is made on purpose because for some
* instructions it DOES NOT make sense to try and emulate the access. Sometimes it
* is WRONG to try and emulate. Here is a list of instruction we don't emulate i.e.,
* the program will get a signal and die:
*
* load/store:
* - ldX.spill
* - stX.spill
* Reason: RNATs are based on addresses
* - ld16
* - st16
* Reason: ld16 and st16 are supposed to occur in a single
* memory op
*
* synchronization:
* - cmpxchg
* - fetchadd
* - xchg
* Reason: ATOMIC operations cannot be emulated properly using multiple
* instructions.
*
* speculative loads:
* - ldX.sZ
* Reason: side effects, code must be ready to deal with failure so simpler
* to let the load fail.
* ---------------------------------------------------------------------------------
* XXX fixme
*
* I would like to get rid of this switch case and do something
* more elegant.
*/
switch (opcode) {
case LDS_OP:
case LDSA_OP:
if (u.insn.x)
/* oops, really a semaphore op (cmpxchg, etc) */
goto failure;
/* no break */
case LDS_IMM_OP:
case LDSA_IMM_OP:
case LDFS_OP:
case LDFSA_OP:
case LDFS_IMM_OP:
/*
* The instruction will be retried with deferred exceptions turned on, and
* we should get Nat bit installed
*
* IMPORTANT: When PSR_ED is set, the register & immediate update forms
* are actually executed even though the operation failed. So we don't
* need to take care of this.
*/
DPRINT("forcing PSR_ED\n");
regs->cr_ipsr |= IA64_PSR_ED;
goto done;
case LD_OP:
case LDA_OP:
case LDBIAS_OP:
case LDACQ_OP:
case LDCCLR_OP:
case LDCNC_OP:
case LDCCLRACQ_OP:
if (u.insn.x)
/* oops, really a semaphore op (cmpxchg, etc) */
goto failure;
/* no break */
case LD_IMM_OP:
case LDA_IMM_OP:
case LDBIAS_IMM_OP:
case LDACQ_IMM_OP:
case LDCCLR_IMM_OP:
case LDCNC_IMM_OP:
case LDCCLRACQ_IMM_OP:
ret = emulate_load_int(ifa, u.insn, regs);
break;
case ST_OP:
case STREL_OP:
if (u.insn.x)
/* oops, really a semaphore op (cmpxchg, etc) */
goto failure;
/* no break */
case ST_IMM_OP:
case STREL_IMM_OP:
ret = emulate_store_int(ifa, u.insn, regs);
break;
case LDF_OP:
case LDFA_OP:
case LDFCCLR_OP:
case LDFCNC_OP:
if (u.insn.x)
ret = emulate_load_floatpair(ifa, u.insn, regs);
else
ret = emulate_load_float(ifa, u.insn, regs);
break;
case LDF_IMM_OP:
case LDFA_IMM_OP:
case LDFCCLR_IMM_OP:
case LDFCNC_IMM_OP:
ret = emulate_load_float(ifa, u.insn, regs);
break;
case STF_OP:
case STF_IMM_OP:
ret = emulate_store_float(ifa, u.insn, regs);
break;
default:
goto failure;
}
DPRINT("ret=%d\n", ret);
if (ret)
goto failure;
if (ipsr->ri == 2)
/*
* given today's architecture this case is not likely to happen because a
* memory access instruction (M) can never be in the last slot of a
* bundle. But let's keep it for now.
*/
regs->cr_iip += 16;
ipsr->ri = (ipsr->ri + 1) & 0x3;
DPRINT("ipsr->ri=%d iip=%lx\n", ipsr->ri, regs->cr_iip);
done:
set_fs(old_fs); /* restore original address limit */
return;
failure:
/* something went wrong... */
if (!user_mode(regs)) {
if (eh) {
ia64_handle_exception(regs, eh);
goto done;
}
if (die_if_kernel("error during unaligned kernel access\n", regs, ret))
return;
/* NOT_REACHED */
}
force_sigbus:
si.si_signo = SIGBUS;
si.si_errno = 0;
si.si_code = BUS_ADRALN;
si.si_addr = (void __user *) ifa;
si.si_flags = 0;
si.si_isr = 0;
si.si_imm = 0;
force_sig_info(SIGBUS, &si, current);
goto done;
}
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