linux/arch/sparc/kernel/unaligned_32.c

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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>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* unaligned.c: Unaligned load/store trap handling with special
* cases for the kernel to do them more quickly.
*
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/mm.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <linux/smp.h>
#include <linux/perf_event.h>
#include <asm/setup.h>
#include "kernel.h"
enum direction {
load, /* ld, ldd, ldh, ldsh */
store, /* st, std, sth, stsh */
both, /* Swap, ldstub, etc. */
fpload,
fpstore,
invalid,
};
static inline enum direction decode_direction(unsigned int insn)
{
unsigned long tmp = (insn >> 21) & 1;
if(!tmp)
return load;
else {
if(((insn>>19)&0x3f) == 15)
return both;
else
return store;
}
}
/* 8 = double-word, 4 = word, 2 = half-word */
static inline int decode_access_size(unsigned int insn)
{
insn = (insn >> 19) & 3;
if(!insn)
return 4;
else if(insn == 3)
return 8;
else if(insn == 2)
return 2;
else {
printk("Impossible unaligned trap. insn=%08x\n", insn);
die_if_kernel("Byte sized unaligned access?!?!", current->thread.kregs);
return 4; /* just to keep gcc happy. */
}
}
/* 0x400000 = signed, 0 = unsigned */
static inline int decode_signedness(unsigned int insn)
{
return (insn & 0x400000);
}
static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
unsigned int rd)
{
if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
/* Wheee... */
__asm__ __volatile__("save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"restore; restore; restore; restore;\n\t"
"restore; restore; restore;\n\t");
}
}
static inline int sign_extend_imm13(int imm)
{
return imm << 19 >> 19;
}
static inline unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
{
struct reg_window32 *win;
if(reg < 16)
return (!reg ? 0 : regs->u_regs[reg]);
/* Ho hum, the slightly complicated case. */
win = (struct reg_window32 *) regs->u_regs[UREG_FP];
return win->locals[reg - 16]; /* yes, I know what this does... */
}
static inline unsigned long safe_fetch_reg(unsigned int reg, struct pt_regs *regs)
{
struct reg_window32 __user *win;
unsigned long ret;
if (reg < 16)
return (!reg ? 0 : regs->u_regs[reg]);
/* Ho hum, the slightly complicated case. */
win = (struct reg_window32 __user *) regs->u_regs[UREG_FP];
if ((unsigned long)win & 3)
return -1;
if (get_user(ret, &win->locals[reg - 16]))
return -1;
return ret;
}
static inline unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
{
struct reg_window32 *win;
if(reg < 16)
return &regs->u_regs[reg];
win = (struct reg_window32 *) regs->u_regs[UREG_FP];
return &win->locals[reg - 16];
}
static unsigned long compute_effective_address(struct pt_regs *regs,
unsigned int insn)
{
unsigned int rs1 = (insn >> 14) & 0x1f;
unsigned int rs2 = insn & 0x1f;
unsigned int rd = (insn >> 25) & 0x1f;
if(insn & 0x2000) {
maybe_flush_windows(rs1, 0, rd);
return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
} else {
maybe_flush_windows(rs1, rs2, rd);
return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
}
}
unsigned long safe_compute_effective_address(struct pt_regs *regs,
unsigned int insn)
{
unsigned int rs1 = (insn >> 14) & 0x1f;
unsigned int rs2 = insn & 0x1f;
unsigned int rd = (insn >> 25) & 0x1f;
if(insn & 0x2000) {
maybe_flush_windows(rs1, 0, rd);
return (safe_fetch_reg(rs1, regs) + sign_extend_imm13(insn));
} else {
maybe_flush_windows(rs1, rs2, rd);
return (safe_fetch_reg(rs1, regs) + safe_fetch_reg(rs2, regs));
}
}
/* This is just to make gcc think panic does return... */
static void unaligned_panic(char *str)
{
panic("%s", str);
}
/* una_asm.S */
extern int do_int_load(unsigned long *dest_reg, int size,
unsigned long *saddr, int is_signed);
extern int __do_int_store(unsigned long *dst_addr, int size,
unsigned long *src_val);
static int do_int_store(int reg_num, int size, unsigned long *dst_addr,
struct pt_regs *regs)
{
unsigned long zero[2] = { 0, 0 };
unsigned long *src_val;
if (reg_num)
src_val = fetch_reg_addr(reg_num, regs);
else {
src_val = &zero[0];
if (size == 8)
zero[1] = fetch_reg(1, regs);
}
return __do_int_store(dst_addr, size, src_val);
}
extern void smp_capture(void);
extern void smp_release(void);
static inline void advance(struct pt_regs *regs)
{
regs->pc = regs->npc;
regs->npc += 4;
}
static inline int floating_point_load_or_store_p(unsigned int insn)
{
return (insn >> 24) & 1;
}
static inline int ok_for_kernel(unsigned int insn)
{
return !floating_point_load_or_store_p(insn);
}
static void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
{
unsigned long g2 = regs->u_regs [UREG_G2];
unsigned long fixup = search_extables_range(regs->pc, &g2);
if (!fixup) {
unsigned long address = compute_effective_address(regs, insn);
if(address < PAGE_SIZE) {
printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference in mna handler");
} else
printk(KERN_ALERT "Unable to handle kernel paging request in mna handler");
printk(KERN_ALERT " at virtual address %08lx\n",address);
printk(KERN_ALERT "current->{mm,active_mm}->context = %08lx\n",
(current->mm ? current->mm->context :
current->active_mm->context));
printk(KERN_ALERT "current->{mm,active_mm}->pgd = %08lx\n",
(current->mm ? (unsigned long) current->mm->pgd :
(unsigned long) current->active_mm->pgd));
die_if_kernel("Oops", regs);
/* Not reached */
}
regs->pc = fixup;
regs->npc = regs->pc + 4;
regs->u_regs [UREG_G2] = g2;
}
asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
{
enum direction dir = decode_direction(insn);
int size = decode_access_size(insn);
if(!ok_for_kernel(insn) || dir == both) {
printk("Unsupported unaligned load/store trap for kernel at <%08lx>.\n",
regs->pc);
unaligned_panic("Wheee. Kernel does fpu/atomic unaligned load/store.");
} else {
unsigned long addr = compute_effective_address(regs, insn);
int err;
perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
switch (dir) {
case load:
err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
regs),
size, (unsigned long *) addr,
decode_signedness(insn));
break;
case store:
err = do_int_store(((insn>>25)&0x1f), size,
(unsigned long *) addr, regs);
break;
default:
panic("Impossible kernel unaligned trap.");
/* Not reached... */
}
if (err)
kernel_mna_trap_fault(regs, insn);
else
advance(regs);
}
}
static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,
enum direction dir)
{
unsigned int reg;
int check = (dir == load) ? VERIFY_READ : VERIFY_WRITE;
int size = ((insn >> 19) & 3) == 3 ? 8 : 4;
if ((regs->pc | regs->npc) & 3)
return 0;
/* Must access_ok() in all the necessary places. */
#define WINREG_ADDR(regnum) \
((void __user *)(((unsigned long *)regs->u_regs[UREG_FP])+(regnum)))
reg = (insn >> 25) & 0x1f;
if (reg >= 16) {
if (!access_ok(check, WINREG_ADDR(reg - 16), size))
return -EFAULT;
}
reg = (insn >> 14) & 0x1f;
if (reg >= 16) {
if (!access_ok(check, WINREG_ADDR(reg - 16), size))
return -EFAULT;
}
if (!(insn & 0x2000)) {
reg = (insn & 0x1f);
if (reg >= 16) {
if (!access_ok(check, WINREG_ADDR(reg - 16), size))
return -EFAULT;
}
}
#undef WINREG_ADDR
return 0;
}
static void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
{
siginfo_t info;
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRALN;
info.si_addr = (void __user *)safe_compute_effective_address(regs, insn);
info.si_trapno = 0;
send_sig_info(SIGBUS, &info, current);
}
asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
{
enum direction dir;
if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
(((insn >> 30) & 3) != 3))
goto kill_user;
dir = decode_direction(insn);
if(!ok_for_user(regs, insn, dir)) {
goto kill_user;
} else {
int err, size = decode_access_size(insn);
unsigned long addr;
if(floating_point_load_or_store_p(insn)) {
printk("User FPU load/store unaligned unsupported.\n");
goto kill_user;
}
addr = compute_effective_address(regs, insn);
perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
switch(dir) {
case load:
err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
regs),
size, (unsigned long *) addr,
decode_signedness(insn));
break;
case store:
err = do_int_store(((insn>>25)&0x1f), size,
(unsigned long *) addr, regs);
break;
case both:
/*
* This was supported in 2.4. However, we question
* the value of SWAP instruction across word boundaries.
*/
printk("Unaligned SWAP unsupported.\n");
err = -EFAULT;
break;
default:
unaligned_panic("Impossible user unaligned trap.");
goto out;
}
if (err)
goto kill_user;
else
advance(regs);
goto out;
}
kill_user:
user_mna_trap_fault(regs, insn);
out:
;
}