projects / zfsonlinux.git / blame
| Commit | Line | Data |
|---|---|---|
| 75b07eca FG |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| 2 | From: Richard Yao <richard.yao@clusterhq.com> | |
| 3 | Date: Tue, 23 Sep 2014 14:29:30 -0400 | |
| 4 | Subject: [PATCH] Implement --enable-debuginfo to force debuginfo | |
| 5 | MIME-Version: 1.0 | |
| 6 | Content-Type: text/plain; charset=UTF-8 | |
| 7 | Content-Transfer-Encoding: 8bit | |
| 8 | ||
| 9 | Inspection of a Ubuntu 14.04 x64 system revealed that the config file | |
| 10 | used to build the kernel image differs from the config file used to | |
| 11 | build kernel modules by the presence of CONFIG_DEBUG_INFO=y: | |
| 12 | ||
| 13 | This in itself is insufficient to show that the kernel is built with | |
| 14 | debuginfo, but a cursory analysis of the debuginfo provided and the | |
| 15 | size of the kernel strongly suggests that it was built with | |
| 16 | CONFIG_DEBUG_INFO=y while the modules were not. Installing | |
| 17 | linux-image-$(uname -r)-dbgsym had no obvious effect on the debuginfo | |
| 18 | provided by either the modules or the kernel. | |
| 19 | ||
| 20 | The consequence is that issue reports from distributions such as Ubuntu | |
| 21 | and its derivatives build kernel modules without debuginfo contain | |
| 22 | nonsensical backtraces. It is therefore desireable to force generation | |
| 23 | of debuginfo, so we implement --enable-debuginfo. Since the build system | |
| 24 | can build both userspace components and kernel modules, the generic | |
| 25 | --enable-debuginfo option will force debuginfo for both. However, it | |
| 26 | also supports --enable-debuginfo=kernel and --enable-debuginfo=user for | |
| 27 | finer grained control. | |
| 28 | ||
| 29 | Enabling debuginfo for the kernel modules works by injecting | |
| 30 | CONFIG_DEBUG_INFO=y into the make environment. This is enables | |
| 31 | generation of debuginfo by the kernel build systems on all Linux | |
| 32 | kernels, but the build environment is slightly different int hat | |
| 33 | CONFIG_DEBUG_INFO has not been in the CPP. Adding -DCONFIG_DEBUG_INFO | |
| 34 | would fix that, but it would also cause build failures on kernels where | |
| 35 | CONFIG_DEBUG_INFO=y is already set. That would complicate its use in | |
| 36 | DKMS environments that support a range of kernels and is therefore | |
| 37 | undesireable. We could write a compatibility shim to enable | |
| 38 | CONFIG_DEBUG_INFO only when it is explicitly disabled, but we forgo | |
| 39 | doing that because it is unnecessary. Nothing in ZoL or the kernel uses | |
| 40 | CONFIG_DEBUG_INFO in the CPP at this time and that is unlikely to | |
| 41 | change. | |
| 42 | ||
| 43 | Enabling debuginfo for the userspace components is done by injecting -g | |
| 44 | into CPPFLAGS. This is not necessary because the build system honors the | |
| 45 | environment's CPPFLAGS by appending them to the actual CPPFLAGS used, | |
| 46 | but it is supported for consistency. | |
| 47 | ||
| 48 | Reviewed-by: Chunwei Chen <tuxoko@gmail.com> | |
| 49 | Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> | |
| 50 | Signed-off-by: Richard Yao <richard.yao@clusterhq.com> | |
| 51 | Closes #2734 | |
| 52 | (cherry picked from commit 834815e9f767c9c5e7220ff84f29b1f069822a4d) | |
| 53 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
| 54 | --- | |
| 55 | configure.ac | 1 + | |
| 56 | config/zfs-build.m4 | 33 ++++++++++++++++++++++++++++++++- | |
| 57 | 2 files changed, 33 insertions(+), 1 deletion(-) | |
| 58 | ||
| 59 | diff --git a/configure.ac b/configure.ac | |
| 60 | index 0c7977ef8..e145aa370 100644 | |
| 61 | --- a/configure.ac | |
| 62 | +++ b/configure.ac | |
| 63 | @@ -55,6 +55,7 @@ ZFS_AC_LICENSE | |
| 64 | ZFS_AC_PACKAGE | |
| 65 | ZFS_AC_CONFIG | |
| 66 | ZFS_AC_DEBUG | |
| 67 | +ZFS_AC_DEBUGINFO | |
| 68 | ||
| 69 | AC_CONFIG_FILES([ | |
| 70 | Makefile | |
| 71 | diff --git a/config/zfs-build.m4 b/config/zfs-build.m4 | |
| 72 | index 78a87aef7..a8609b829 100644 | |
| 73 | --- a/config/zfs-build.m4 | |
| 74 | +++ b/config/zfs-build.m4 | |
| 75 | @@ -38,12 +38,43 @@ AC_DEFUN([ZFS_AC_DEBUG], [ | |
| 76 | [ZFS_AC_DEBUG_DISABLE], | |
| 77 | [AC_MSG_ERROR([Unknown option $enable_debug])]) | |
| 78 | ||
| 79 | - AC_SUBST(DEBUG_CFLAGS) | |
| 80 | AC_SUBST(DEBUG_STACKFLAGS) | |
| 81 | AC_SUBST(DEBUG_ZFS) | |
| 82 | AC_MSG_RESULT([$enable_debug]) | |
| 83 | ]) | |
| 84 | ||
| 85 | +AC_DEFUN([ZFS_AC_DEBUGINFO_KERNEL], [ | |
| 86 | + KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS CONFIG_DEBUG_INFO=y" | |
| 87 | +]) | |
| 88 | + | |
| 89 | +AC_DEFUN([ZFS_AC_DEBUGINFO_USER], [ | |
| 90 | + DEBUG_CFLAGS="$DEBUG_CFLAGS -g" | |
| 91 | +]) | |
| 92 | + | |
| 93 | +AC_DEFUN([ZFS_AC_DEBUGINFO], [ | |
| 94 | + AC_MSG_CHECKING([whether debuginfo support will be forced]) | |
| 95 | + AC_ARG_ENABLE([debuginfo], | |
| 96 | + [AS_HELP_STRING([--enable-debuginfo], | |
| 97 | + [Force generation of debuginfo @<:@default=no@:>@])], | |
| 98 | + [], | |
| 99 | + [enable_debuginfo=no]) | |
| 100 | + | |
| 101 | + AS_CASE(["x$enable_debuginfo"], | |
| 102 | + ["xyes"], | |
| 103 | + [ZFS_AC_DEBUGINFO_KERNEL | |
| 104 | + ZFS_AC_DEBUGINFO_USER], | |
| 105 | + ["xkernel"], | |
| 106 | + [ZFS_AC_DEBUGINFO_KERNEL], | |
| 107 | + ["xuser"], | |
| 108 | + [ZFS_AC_DEBUGINFO_USER], | |
| 109 | + ["xno"], | |
| 110 | + [], | |
| 111 | + [AC_MSG_ERROR([Unknown option $enable_debug])]) | |
| 112 | + | |
| 113 | + AC_SUBST(DEBUG_CFLAGS) | |
| 114 | + AC_MSG_RESULT([$enable_debuginfo]) | |
| 115 | +]) | |
| 116 | + | |
| 117 | AC_DEFUN([ZFS_AC_CONFIG_ALWAYS], [ | |
| 118 | ZFS_AC_CONFIG_ALWAYS_NO_UNUSED_BUT_SET_VARIABLE | |
| 119 | ZFS_AC_CONFIG_ALWAYS_NO_BOOL_COMPARE | |
| 120 | -- | |
| 121 | 2.14.2 | |
| 122 |