[systemd-commits] 3 commits - src/libsystemd-terminal src/locale src/shared
David Herrmann
dvdhrm at kemper.freedesktop.org
Mon Nov 3 23:28:38 PST 2014
src/libsystemd-terminal/grdev-drm.c | 8 ++++----
src/locale/localectl.c | 2 +-
src/shared/missing.h | 11 +++++++++--
src/shared/util.h | 9 +++++++++
4 files changed, 23 insertions(+), 7 deletions(-)
New commits:
commit 44dd2c6e861316d26a78848eb0f6b35bd3b82d4b
Author: David Herrmann <dh.herrmann at gmail.com>
Date: Mon Nov 3 18:23:28 2014 +0100
util: introduce negative_errno()
Imagine a constructor like this:
int object_new(void **out) {
void *my_object;
int r;
...
r = ioctl(...);
if (r < 0)
return -errno;
...
*out = my_object;
return 0;
}
We have a lot of those in systemd. If you now call those, gcc might inline
the call and optimize it. However, gcc cannot know that "errno" is
negative if "r" is. Therefore, a caller like this will produce warnings:
r = object_new(&obj);
if (r < 0)
return r;
obj->xyz = "foobar";
In case the ioctl in the constructor fails, gcc might assume "errno" is 0
and thus the error-handling is not triggered. Therefore, "obj" is
uninitialized, but accessed. Gcc will warn about that.
The new negative_errno() helper can be used to mitigate those warnings.
The helper is guaranteed to return a negative integer. Furthermore, it
spills out runtime warnings if "errno" is non-negative.
Instead of returning "-errno", you can use:
return negative_errno();
gcc will no longer assume that this can return >=0, thus, it will not warn
about it.
Use this new helper in libsystemd-terminal to fix some grdev-drm warnings.
diff --git a/src/libsystemd-terminal/grdev-drm.c b/src/libsystemd-terminal/grdev-drm.c
index dba6db2..48f8e9c 100644
--- a/src/libsystemd-terminal/grdev-drm.c
+++ b/src/libsystemd-terminal/grdev-drm.c
@@ -1393,7 +1393,7 @@ static int grdrm_fb_new(grdrm_fb **out, grdrm_card *card, const struct drm_mode_
r = ioctl(card->fd, DRM_IOCTL_MODE_CREATE_DUMB, &create_dumb);
if (r < 0) {
- r = -errno;
+ r = negative_errno();
log_debug("grdrm: %s: cannot create dumb buffer %" PRIu32 "x%" PRIu32": %m",
card->base.name, fb->base.width, fb->base.height);
return r;
@@ -1407,7 +1407,7 @@ static int grdrm_fb_new(grdrm_fb **out, grdrm_card *card, const struct drm_mode_
r = ioctl(card->fd, DRM_IOCTL_MODE_MAP_DUMB, &map_dumb);
if (r < 0) {
- r = -errno;
+ r = negative_errno();
log_debug("grdrm: %s: cannot map dumb buffer %" PRIu32 "x%" PRIu32": %m",
card->base.name, fb->base.width, fb->base.height);
return r;
@@ -1415,7 +1415,7 @@ static int grdrm_fb_new(grdrm_fb **out, grdrm_card *card, const struct drm_mode_
fb->base.maps[0] = mmap(0, fb->sizes[0], PROT_WRITE, MAP_SHARED, card->fd, map_dumb.offset);
if (fb->base.maps[0] == MAP_FAILED) {
- r = -errno;
+ r = negative_errno();
log_debug("grdrm: %s: cannot memory-map dumb buffer %" PRIu32 "x%" PRIu32": %m",
card->base.name, fb->base.width, fb->base.height);
return r;
@@ -1433,7 +1433,7 @@ static int grdrm_fb_new(grdrm_fb **out, grdrm_card *card, const struct drm_mode_
r = ioctl(card->fd, DRM_IOCTL_MODE_ADDFB2, &add_fb);
if (r < 0) {
- r = -errno;
+ r = negative_errno();
log_debug("grdrm: %s: cannot add framebuffer %" PRIu32 "x%" PRIu32": %m",
card->base.name, fb->base.width, fb->base.height);
return r;
diff --git a/src/shared/util.h b/src/shared/util.h
index e405b02..af589b6 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -794,6 +794,15 @@ static inline void _reset_errno_(int *saved_errno) {
#define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
+static inline int negative_errno(void) {
+ /* This helper should be used to shut up gcc if you know 'errno' is
+ * negative. Instead of "return -errno;", use "return negative_errno();"
+ * It will suppress bogus gcc warnings in case it assumes 'errno' might
+ * be 0 and thus the caller's error-handling might not be triggered. */
+ assert_return(errno > 0, -EINVAL);
+ return -errno;
+}
+
struct _umask_struct_ {
mode_t mask;
bool quit;
commit e6c019026b8cfd27a997e6e6ed1349f8f289b7e2
Author: Vicente Olivert Riera <Vincent.Riera at imgtec.com>
Date: Mon Nov 3 14:48:35 2014 +0000
Properly define the __NR_memfd_create macro for MIPS
This macro exists for MIPS since v3.17:
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=42944521af97a3b25516f15f3149aec3779656dc
diff --git a/src/shared/missing.h b/src/shared/missing.h
index cc81c98..ecd32ba 100644
--- a/src/shared/missing.h
+++ b/src/shared/missing.h
@@ -126,8 +126,15 @@ static inline int pivot_root(const char *new_root, const char *put_old) {
# elif defined __arm__
# define __NR_memfd_create 385
# elif defined _MIPS_SIM
-# warning "__NR_memfd_create not yet defined for MIPS"
-# define __NR_memfd_create 0xffffffff
+# if _MIPS_SIM == _MIPS_SIM_ABI32
+# define __NR_memfd_create 4354
+# endif
+# if _MIPS_SIM == _MIPS_SIM_NABI32
+# define __NR_memfd_create 6318
+# endif
+# if _MIPS_SIM == _MIPS_SIM_ABI64
+# define __NR_memfd_create 5314
+# endif
# else
# define __NR_memfd_create 356
# endif
commit 31cf921abbeafc9dae2d5c777f3e2285e6f4c19d
Author: Jan Synacek <jsynacek at redhat.com>
Date: Mon Nov 3 14:01:04 2014 +0100
localectl: fix localectl set-x11-keymap syntax description
This complements the fix in:
commit cd4c6fb12598435fe24431f1dd616f9582f0e3bd
Author: Jan Synacek <jsynacek at redhat.com>
Date: Mon Oct 20 12:43:39 2014 +0200
man: fix localectl set-x11-keymap syntax description
diff --git a/src/locale/localectl.c b/src/locale/localectl.c
index 3690f9f..d4a2d29 100644
--- a/src/locale/localectl.c
+++ b/src/locale/localectl.c
@@ -505,7 +505,7 @@ static void help(void) {
" list-locales Show known locales\n"
" set-keymap MAP [MAP] Set virtual console keyboard mapping\n"
" list-keymaps Show known virtual console keyboard mappings\n"
- " set-x11-keymap LAYOUT [MODEL] [VARIANT] [OPTIONS]\n"
+ " set-x11-keymap LAYOUT [MODEL [VARIANT [OPTIONS]]]\n"
" Set X11 keyboard mapping\n"
" list-x11-keymap-models Show known X11 keyboard mapping models\n"
" list-x11-keymap-layouts Show known X11 keyboard mapping layouts\n"
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