diff mbox series

linux-user: Fix sched_get/setaffinity conversion

Message ID 20171228193439.18835-1-samuel.thibault@ens-lyon.org
State New
Headers show
Series linux-user: Fix sched_get/setaffinity conversion | expand

Commit Message

Samuel Thibault Dec. 28, 2017, 7:34 p.m. UTC 
sched_get/setaffinity linux-user syscalls were missing conversions for
little/big endian, which is hairy since longs may not be the same size
either.

For simplicity, this just introduces loops to convert bit by bit like is
done for select.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
---
 linux-user/syscall.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 67 insertions(+), 8 deletions(-)

Comments

no-reply@patchew.org Dec. 28, 2017, 7:48 p.m. UTC | #1 
Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20171228193439.18835-1-samuel.thibault@ens-lyon.org
Subject: [Qemu-devel] [PATCH] linux-user: Fix sched_get/setaffinity conversion

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

git config --local diff.renamelimit 0
git config --local diff.renames True

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
1014702f1b linux-user: Fix sched_get/setaffinity conversion

=== OUTPUT BEGIN ===
Checking PATCH 1/1: linux-user: Fix sched_get/setaffinity conversion...
ERROR: line over 90 characters
#24: FILE: linux-user/syscall.c:7719:
+static int target_to_host_cpu_mask(unsigned long *host_mask, size_t host_size, abi_ulong target_addr, size_t target_size)

ERROR: line over 90 characters
#55: FILE: linux-user/syscall.c:7750:
+static int host_to_target_cpu_mask(const unsigned long *host_mask, size_t host_size, abi_ulong target_addr, size_t target_size)

total: 2 errors, 0 warnings, 101 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

=== OUTPUT END ===

Test command exited with code: 1


---
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Please send your feedback to patchew-devel@freelists.org
Laurent Vivier Jan. 8, 2018, 9:35 a.m. UTC | #2 
Le 28/12/2017 à 20:34, Samuel Thibault a écrit :
> sched_get/setaffinity linux-user syscalls were missing conversions for
> little/big endian, which is hairy since longs may not be the same size
> either.
> 
> For simplicity, this just introduces loops to convert bit by bit like is
> done for select.
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> ---

You should add a version in your subject prefix and a version history of
your patch here.

>  linux-user/syscall.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 67 insertions(+), 8 deletions(-)
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
diff mbox series

Patch

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 11c9116c4a..f806cfb9a7 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7716,6 +7716,67 @@  static TargetFdTrans target_inotify_trans = {
 };
 #endif
 
+static int target_to_host_cpu_mask(unsigned long *host_mask, size_t host_size, abi_ulong target_addr, size_t target_size)
+{
+    unsigned target_bits = sizeof(abi_ulong) * 8;
+    unsigned host_bits = sizeof(*host_mask) * 8;
+    abi_ulong *target_mask;
+    unsigned i, j;
+
+    assert(host_size >= target_size);
+
+    target_mask = lock_user(VERIFY_READ, target_addr, target_size, 1);
+    if (!target_mask) {
+        return -TARGET_EFAULT;
+    }
+    memset(host_mask, 0, host_size);
+
+    for (i = 0 ; i < target_size / sizeof(abi_ulong); i++) {
+        unsigned bit = i * target_bits;
+        abi_ulong val;
+
+        __get_user(val, &target_mask[i]);
+        for (j = 0; j < target_bits; j++, bit++) {
+            if (val & (1UL << j)) {
+                host_mask[bit / host_bits] |= 1UL << (bit % host_bits);
+            }
+        }
+    }
+
+    unlock_user(target_mask, target_addr, 0);
+    return 0;
+}
+
+static int host_to_target_cpu_mask(const unsigned long *host_mask, size_t host_size, abi_ulong target_addr, size_t target_size)
+{
+    unsigned target_bits = sizeof(abi_ulong) * 8;
+    unsigned host_bits = sizeof(*host_mask) * 8;
+    abi_ulong *target_mask;
+    unsigned i, j;
+
+    assert(host_size >= target_size);
+
+    target_mask = lock_user(VERIFY_WRITE, target_addr, target_size, 0);
+    if (!target_mask) {
+        return -TARGET_EFAULT;
+    }
+
+    for (i = 0 ; i < target_size / sizeof(abi_ulong); i++) {
+        unsigned bit = i * target_bits;
+        abi_ulong val = 0;
+
+        for (j = 0; j < target_bits; j++, bit++) {
+            if (host_mask[bit / host_bits] & (1UL << (bit % host_bits))) {
+                val |= 1UL << j;
+            }
+        }
+        __put_user(val, &target_mask[i]);
+    }
+
+    unlock_user(target_mask, target_addr, target_size);
+    return 0;
+}
+
 /* do_syscall() should always have a single exit point at the end so
    that actions, such as logging of syscall results, can be performed.
    All errnos that do_syscall() returns must be -TARGET_<errcode>. */
@@ -10353,6 +10414,7 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             mask_size = (arg2 + (sizeof(*mask) - 1)) & ~(sizeof(*mask) - 1);
 
             mask = alloca(mask_size);
+            memset(mask, 0, mask_size);
             ret = get_errno(sys_sched_getaffinity(arg1, mask_size, mask));
 
             if (!is_error(ret)) {
@@ -10372,9 +10434,7 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
                     ret = arg2;
                 }
 
-                if (copy_to_user(arg3, mask, ret)) {
-                    goto efault;
-                }
+                ret = host_to_target_cpu_mask(mask, mask_size, arg3, arg2);
             }
         }
         break;
@@ -10392,13 +10452,12 @@  abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
                 break;
             }
             mask_size = (arg2 + (sizeof(*mask) - 1)) & ~(sizeof(*mask) - 1);
-
             mask = alloca(mask_size);
-            if (!lock_user_struct(VERIFY_READ, p, arg3, 1)) {
-                goto efault;
+
+            ret = target_to_host_cpu_mask(mask, mask_size, arg3, arg2);
+            if (ret) {
+                break;
             }
-            memcpy(mask, p, arg2);
-            unlock_user_struct(p, arg2, 0);
 
             ret = get_errno(sys_sched_setaffinity(arg1, mask_size, mask));
         }