arch/tile: Miscellaneous cleanup changes.

This commit is primarily changes caused by reviewing "sparse"
and "checkpatch" output on our sources, so is somewhat noisy, since
things like "printk() -> pr_err()" (or whatever) throughout the
codebase tend to get tedious to read.  Rather than trying to tease
apart precisely which things changed due to which type of code
review, this commit includes various cleanups in the code:

- sparse: Add declarations in headers for globals.
- sparse: Fix __user annotations.
- sparse: Using gfp_t consistently instead of int.
- sparse: removing functions not actually used.
- checkpatch: Clean up printk() warnings by using pr_info(), etc.;
  also avoid partial-line printks except in bootup code.
  - checkpatch: Use exposed structs rather than typedefs.
  - checkpatch: Change some C99 comments to C89 comments.

In addition, a couple of minor other changes are rolled in
to this commit:

- Add support for a "raise" instruction to cause SIGFPE, etc., to be raised.
- Remove some compat code that is unnecessary when we fully eliminate
  some of the deprecated syscalls from the generic syscall ABI.
- Update the tile_defconfig to reflect current config contents.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 41 insertions, 34 deletions

diff --git a/arch/tile/kernel/single_step.c b/arch/tile/kernel/single_step.c
index 266aae123632..5ec4b9c651f2 100644
--- a/arch/tile/kernel/single_step.c
+++ b/arch/tile/kernel/single_step.c
@@ -23,6 +23,7 @@
 #include <linux/uaccess.h>
 #include <linux/mman.h>
 #include <linux/types.h>
+#include <linux/err.h>
 #include <asm/cacheflush.h>
 #include <asm/opcode-tile.h>
 #include <asm/opcode_constants.h>
@@ -39,8 +40,8 @@ static int __init setup_unaligned_printk(char *str)
         if (strict_strtol(str, 0, &val) != 0)
                 return 0;
         unaligned_printk = val;
-        printk("Printk for each unaligned data accesses is %s\n",
-               unaligned_printk ? "enabled" : "disabled");
+        pr_info("Printk for each unaligned data accesses is %s\n",
+                unaligned_printk ? "enabled" : "disabled");
         return 1;
 }
 __setup("unaligned_printk=", setup_unaligned_printk);
@@ -113,7 +114,7 @@ static tile_bundle_bits rewrite_load_store_unaligned(
         enum mem_op mem_op,
         int size, int sign_ext)
 {
-        unsigned char *addr;
+        unsigned char __user *addr;
         int val_reg, addr_reg, err, val;
 
         /* Get address and value registers */
@@ -148,7 +149,7 @@ static tile_bundle_bits rewrite_load_store_unaligned(
                 return bundle;
 
         /* If it's aligned, don't handle it specially */
-        addr = (void *)regs->regs[addr_reg];
+        addr = (void __user *)regs->regs[addr_reg];
         if (((unsigned long)addr % size) == 0)
                 return bundle;
 
@@ -183,7 +184,7 @@ static tile_bundle_bits rewrite_load_store_unaligned(
                 siginfo_t info = {
                         .si_signo = SIGSEGV,
                         .si_code = SEGV_MAPERR,
-                        .si_addr = (void __user *)addr
+                        .si_addr = addr
                 };
                 force_sig_info(info.si_signo, &info, current);
                 return (tile_bundle_bits) 0;
@@ -193,30 +194,33 @@ static tile_bundle_bits rewrite_load_store_unaligned(
                 siginfo_t info = {
                         .si_signo = SIGBUS,
                         .si_code = BUS_ADRALN,
-                        .si_addr = (void __user *)addr
+                        .si_addr = addr
                 };
                 force_sig_info(info.si_signo, &info, current);
                 return (tile_bundle_bits) 0;
         }
 
         if (unaligned_printk || unaligned_fixup_count == 0) {
-                printk("Process %d/%s: PC %#lx: Fixup of"
-                       " unaligned %s at %#lx.\n",
-                       current->pid, current->comm, regs->pc,
-                       (mem_op == MEMOP_LOAD || mem_op == MEMOP_LOAD_POSTINCR) ?
-                         "load" : "store",
-                       (unsigned long)addr);
+                pr_info("Process %d/%s: PC %#lx: Fixup of"
+                        " unaligned %s at %#lx.\n",
+                        current->pid, current->comm, regs->pc,
+                        (mem_op == MEMOP_LOAD ||
+                         mem_op == MEMOP_LOAD_POSTINCR) ?
+                        "load" : "store",
+                        (unsigned long)addr);
                 if (!unaligned_printk) {
-                        printk("\n"
-"Unaligned fixups in the kernel will slow your application considerably.\n"
-"You can find them by writing \"1\" to /proc/sys/tile/unaligned_fixup/printk,\n"
-"which requests the kernel show all unaligned fixups, or writing a \"0\"\n"
-"to /proc/sys/tile/unaligned_fixup/enabled, in which case each unaligned\n"
-"access will become a SIGBUS you can debug. No further warnings will be\n"
-"shown so as to avoid additional slowdown, but you can track the number\n"
-"of fixups performed via /proc/sys/tile/unaligned_fixup/count.\n"
-"Use the tile-addr2line command (see \"info addr2line\") to decode PCs.\n"
-                                "\n");
+#define P pr_info
+P("\n");
+P("Unaligned fixups in the kernel will slow your application considerably.\n");
+P("To find them, write a \"1\" to /proc/sys/tile/unaligned_fixup/printk,\n");
+P("which requests the kernel show all unaligned fixups, or write a \"0\"\n");
+P("to /proc/sys/tile/unaligned_fixup/enabled, in which case each unaligned\n");
+P("access will become a SIGBUS you can debug. No further warnings will be\n");
+P("shown so as to avoid additional slowdown, but you can track the number\n");
+P("of fixups performed via /proc/sys/tile/unaligned_fixup/count.\n");
+P("Use the tile-addr2line command (see \"info addr2line\") to decode PCs.\n");
+P("\n");
+#undef P
                 }
         }
         ++unaligned_fixup_count;
@@ -276,7 +280,7 @@ void single_step_once(struct pt_regs *regs)
         struct thread_info *info = (void *)current_thread_info();
         struct single_step_state *state = info->step_state;
         int is_single_step = test_ti_thread_flag(info, TIF_SINGLESTEP);
-        tile_bundle_bits *buffer, *pc;
+        tile_bundle_bits __user *buffer, *pc;
         tile_bundle_bits bundle;
         int temp_reg;
         int target_reg = TREG_LR;
@@ -306,21 +310,21 @@ void single_step_once(struct pt_regs *regs)
                 /* allocate a page of writable, executable memory */
                 state = kmalloc(sizeof(struct single_step_state), GFP_KERNEL);
                 if (state == NULL) {
-                        printk("Out of kernel memory trying to single-step\n");
+                        pr_err("Out of kernel memory trying to single-step\n");
                         return;
                 }
 
                 /* allocate a cache line of writable, executable memory */
                 down_write(&current->mm->mmap_sem);
-                buffer = (void *) do_mmap(0, 0, 64,
+                buffer = (void __user *) do_mmap(NULL, 0, 64,
                                           PROT_EXEC | PROT_READ | PROT_WRITE,
                                           MAP_PRIVATE | MAP_ANONYMOUS,
                                           0);
                 up_write(&current->mm->mmap_sem);
 
-                if ((int)buffer < 0 && (int)buffer > -PAGE_SIZE) {
+                if (IS_ERR((void __force *)buffer)) {
                         kfree(state);
-                        printk("Out of kernel pages trying to single-step\n");
+                        pr_err("Out of kernel pages trying to single-step\n");
                         return;
                 }
 
@@ -349,11 +353,14 @@ void single_step_once(struct pt_regs *regs)
         if (regs->faultnum == INT_SWINT_1)
                 regs->pc -= 8;
 
-        pc = (tile_bundle_bits *)(regs->pc);
-        bundle = pc[0];
+        pc = (tile_bundle_bits __user *)(regs->pc);
+        if (get_user(bundle, pc) != 0) {
+                pr_err("Couldn't read instruction at %p trying to step\n", pc);
+                return;
+        }
 
         /* We'll follow the instruction with 2 ill op bundles */
-        state->orig_pc = (unsigned long) pc;
+        state->orig_pc = (unsigned long)pc;
         state->next_pc = (unsigned long)(pc + 1);
         state->branch_next_pc = 0;
         state->update = 0;
@@ -633,7 +640,7 @@ void single_step_once(struct pt_regs *regs)
         }
 
         if (err) {
-                printk("Fault when writing to single-step buffer\n");
+                pr_err("Fault when writing to single-step buffer\n");
                 return;
         }
 
@@ -641,12 +648,12 @@ void single_step_once(struct pt_regs *regs)
          * Flush the buffer.
          * We do a local flush only, since this is a thread-specific buffer.
          */
-        __flush_icache_range((unsigned long) state->buffer,
-                             (unsigned long) buffer);
+        __flush_icache_range((unsigned long)state->buffer,
+                             (unsigned long)buffer);
 
         /* Indicate enabled */
         state->is_enabled = is_single_step;
-        regs->pc = (unsigned long) state->buffer;
+        regs->pc = (unsigned long)state->buffer;
 
         /* Fault immediately if we are coming back from a syscall. */
         if (regs->faultnum == INT_SWINT_1)