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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Kees Cook <keescook@chromium.org>
Subject: [PATCH 4.14 35/68] compiler.h: enable builtin overflow checkers and add fallback code
Date: Tue, 29 Jan 2019 12:35:57 +0100
Message-ID: <20190129113134.496215747@linuxfoundation.org> (raw)
In-Reply-To: <20190129113131.751891514@linuxfoundation.org>

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

commit f0907827a8a9152aedac2833ed1b674a7b2a44f2 upstream.

This adds wrappers for the __builtin overflow checkers present in gcc
5.1+ as well as fallback implementations for earlier compilers. It's not
that easy to implement the fully generic __builtin_X_overflow(T1 a, T2
b, T3 *d) in macros, so the fallback code assumes that T1, T2 and T3 are
the same. We obviously don't want the wrappers to have different
semantics depending on $GCC_VERSION, so we also insist on that even when
using the builtins.

There are a few problems with the 'a+b < a' idiom for checking for
overflow: For signed types, it relies on undefined behaviour and is
not actually complete (it doesn't check underflow;
e.g. INT_MIN+INT_MIN == 0 isn't caught). Due to type promotion it
is wrong for all types (signed and unsigned) narrower than
int. Similarly, when a and b does not have the same type, there are
subtle cases like

  u32 a;

  if (a + sizeof(foo) < a)
    return -EOVERFLOW;
  a += sizeof(foo);

where the test is always false on 64 bit platforms. Add to that that it
is not always possible to determine the types involved at a glance.

The new overflow.h is somewhat bulky, but that's mostly a result of
trying to be type-generic, complete (e.g. catching not only overflow
but also signed underflow) and not relying on undefined behaviour.

Linus is of course right [1] that for unsigned subtraction a-b, the
right way to check for overflow (underflow) is "b > a" and not
"__builtin_sub_overflow(a, b, &d)", but that's just one out of six cases
covered here, and included mostly for completeness.

So is it worth it? I think it is, if nothing else for the documentation
value of seeing

  if (check_add_overflow(a, b, &d))
    return -EGOAWAY;
  do_stuff_with(d);

instead of the open-coded (and possibly wrong and/or incomplete and/or
UBsan-tickling)

  if (a+b < a)
    return -EGOAWAY;
  do_stuff_with(a+b);

While gcc does recognize the 'a+b < a' idiom for testing unsigned add
overflow, it doesn't do nearly as good for unsigned multiplication
(there's also no single well-established idiom). So using
check_mul_overflow in kcalloc and friends may also make gcc generate
slightly better code.

[1] https://lkml.org/lkml/2015/11/2/658

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/compiler-clang.h |   14 ++
 include/linux/compiler-gcc.h   |    4 
 include/linux/compiler-intel.h |    4 
 include/linux/overflow.h       |  205 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 227 insertions(+)

--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -24,3 +24,17 @@
 #ifdef __noretpoline
 #undef __noretpoline
 #endif
+
+/*
+ * Not all versions of clang implement the the type-generic versions
+ * of the builtin overflow checkers. Fortunately, clang implements
+ * __has_builtin allowing us to avoid awkward version
+ * checks. Unfortunately, we don't know which version of gcc clang
+ * pretends to be, so the macro may or may not be defined.
+ */
+#undef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
+#if __has_builtin(__builtin_mul_overflow) && \
+    __has_builtin(__builtin_add_overflow) && \
+    __has_builtin(__builtin_sub_overflow)
+#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
+#endif
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -358,3 +358,7 @@
  * code
  */
 #define uninitialized_var(x) x = x
+
+#if GCC_VERSION >= 50100
+#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
+#endif
--- a/include/linux/compiler-intel.h
+++ b/include/linux/compiler-intel.h
@@ -44,3 +44,7 @@
 #define __builtin_bswap16 _bswap16
 #endif
 
+/*
+ * icc defines __GNUC__, but does not implement the builtin overflow checkers.
+ */
+#undef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
--- /dev/null
+++ b/include/linux/overflow.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+#ifndef __LINUX_OVERFLOW_H
+#define __LINUX_OVERFLOW_H
+
+#include <linux/compiler.h>
+
+/*
+ * In the fallback code below, we need to compute the minimum and
+ * maximum values representable in a given type. These macros may also
+ * be useful elsewhere, so we provide them outside the
+ * COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW block.
+ *
+ * It would seem more obvious to do something like
+ *
+ * #define type_min(T) (T)(is_signed_type(T) ? (T)1 << (8*sizeof(T)-1) : 0)
+ * #define type_max(T) (T)(is_signed_type(T) ? ((T)1 << (8*sizeof(T)-1)) - 1 : ~(T)0)
+ *
+ * Unfortunately, the middle expressions, strictly speaking, have
+ * undefined behaviour, and at least some versions of gcc warn about
+ * the type_max expression (but not if -fsanitize=undefined is in
+ * effect; in that case, the warning is deferred to runtime...).
+ *
+ * The slightly excessive casting in type_min is to make sure the
+ * macros also produce sensible values for the exotic type _Bool. [The
+ * overflow checkers only almost work for _Bool, but that's
+ * a-feature-not-a-bug, since people shouldn't be doing arithmetic on
+ * _Bools. Besides, the gcc builtins don't allow _Bool* as third
+ * argument.]
+ *
+ * Idea stolen from
+ * https://mail-index.netbsd.org/tech-misc/2007/02/05/0000.html -
+ * credit to Christian Biere.
+ */
+#define is_signed_type(type)       (((type)(-1)) < (type)1)
+#define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type)))
+#define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T)))
+#define type_min(T) ((T)((T)-type_max(T)-(T)1))
+
+
+#ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
+/*
+ * For simplicity and code hygiene, the fallback code below insists on
+ * a, b and *d having the same type (similar to the min() and max()
+ * macros), whereas gcc's type-generic overflow checkers accept
+ * different types. Hence we don't just make check_add_overflow an
+ * alias for __builtin_add_overflow, but add type checks similar to
+ * below.
+ */
+#define check_add_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	__builtin_add_overflow(__a, __b, __d);	\
+})
+
+#define check_sub_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	__builtin_sub_overflow(__a, __b, __d);	\
+})
+
+#define check_mul_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	__builtin_mul_overflow(__a, __b, __d);	\
+})
+
+#else
+
+
+/* Checking for unsigned overflow is relatively easy without causing UB. */
+#define __unsigned_add_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = __a + __b;			\
+	*__d < __a;				\
+})
+#define __unsigned_sub_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = __a - __b;			\
+	__a < __b;				\
+})
+/*
+ * If one of a or b is a compile-time constant, this avoids a division.
+ */
+#define __unsigned_mul_overflow(a, b, d) ({		\
+	typeof(a) __a = (a);				\
+	typeof(b) __b = (b);				\
+	typeof(d) __d = (d);				\
+	(void) (&__a == &__b);				\
+	(void) (&__a == __d);				\
+	*__d = __a * __b;				\
+	__builtin_constant_p(__b) ?			\
+	  __b > 0 && __a > type_max(typeof(__a)) / __b : \
+	  __a > 0 && __b > type_max(typeof(__b)) / __a;	 \
+})
+
+/*
+ * For signed types, detecting overflow is much harder, especially if
+ * we want to avoid UB. But the interface of these macros is such that
+ * we must provide a result in *d, and in fact we must produce the
+ * result promised by gcc's builtins, which is simply the possibly
+ * wrapped-around value. Fortunately, we can just formally do the
+ * operations in the widest relevant unsigned type (u64) and then
+ * truncate the result - gcc is smart enough to generate the same code
+ * with and without the (u64) casts.
+ */
+
+/*
+ * Adding two signed integers can overflow only if they have the same
+ * sign, and overflow has happened iff the result has the opposite
+ * sign.
+ */
+#define __signed_add_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = (u64)__a + (u64)__b;		\
+	(((~(__a ^ __b)) & (*__d ^ __a))	\
+		& type_min(typeof(__a))) != 0;	\
+})
+
+/*
+ * Subtraction is similar, except that overflow can now happen only
+ * when the signs are opposite. In this case, overflow has happened if
+ * the result has the opposite sign of a.
+ */
+#define __signed_sub_overflow(a, b, d) ({	\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	typeof(d) __d = (d);			\
+	(void) (&__a == &__b);			\
+	(void) (&__a == __d);			\
+	*__d = (u64)__a - (u64)__b;		\
+	((((__a ^ __b)) & (*__d ^ __a))		\
+		& type_min(typeof(__a))) != 0;	\
+})
+
+/*
+ * Signed multiplication is rather hard. gcc always follows C99, so
+ * division is truncated towards 0. This means that we can write the
+ * overflow check like this:
+ *
+ * (a > 0 && (b > MAX/a || b < MIN/a)) ||
+ * (a < -1 && (b > MIN/a || b < MAX/a) ||
+ * (a == -1 && b == MIN)
+ *
+ * The redundant casts of -1 are to silence an annoying -Wtype-limits
+ * (included in -Wextra) warning: When the type is u8 or u16, the
+ * __b_c_e in check_mul_overflow obviously selects
+ * __unsigned_mul_overflow, but unfortunately gcc still parses this
+ * code and warns about the limited range of __b.
+ */
+
+#define __signed_mul_overflow(a, b, d) ({				\
+	typeof(a) __a = (a);						\
+	typeof(b) __b = (b);						\
+	typeof(d) __d = (d);						\
+	typeof(a) __tmax = type_max(typeof(a));				\
+	typeof(a) __tmin = type_min(typeof(a));				\
+	(void) (&__a == &__b);						\
+	(void) (&__a == __d);						\
+	*__d = (u64)__a * (u64)__b;					\
+	(__b > 0   && (__a > __tmax/__b || __a < __tmin/__b)) ||	\
+	(__b < (typeof(__b))-1  && (__a > __tmin/__b || __a < __tmax/__b)) || \
+	(__b == (typeof(__b))-1 && __a == __tmin);			\
+})
+
+
+#define check_add_overflow(a, b, d)					\
+	__builtin_choose_expr(is_signed_type(typeof(a)),		\
+			__signed_add_overflow(a, b, d),			\
+			__unsigned_add_overflow(a, b, d))
+
+#define check_sub_overflow(a, b, d)					\
+	__builtin_choose_expr(is_signed_type(typeof(a)),		\
+			__signed_sub_overflow(a, b, d),			\
+			__unsigned_sub_overflow(a, b, d))
+
+#define check_mul_overflow(a, b, d)					\
+	__builtin_choose_expr(is_signed_type(typeof(a)),		\
+			__signed_mul_overflow(a, b, d),			\
+			__unsigned_mul_overflow(a, b, d))
+
+
+#endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */
+
+#endif /* __LINUX_OVERFLOW_H */



  parent reply index

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-29 11:35 [PATCH 4.14 00/68] 4.14.97-stable review Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 01/68] amd-xgbe: Fix mdio access for non-zero ports and clause 45 PHYs Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 02/68] net: bridge: Fix ethernet header pointer before check skb forwardable Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 03/68] net: Fix usage of pskb_trim_rcsum Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 04/68] net: phy: mdio_bus: add missing device_del() in mdiobus_register() error handling Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 05/68] net_sched: refetch skb protocol for each filter Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 06/68] openvswitch: Avoid OOB read when parsing flow nlattrs Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 07/68] vhost: log dirty page correctly Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 08/68] net: ipv4: Fix memory leak in network namespace dismantle Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 09/68] tcp: allow MSG_ZEROCOPY transmission also in CLOSE_WAIT state Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 10/68] ipfrag: really prevent allocation on netns exit Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 11/68] mmc: Kconfig: Enable CONFIG_MMC_SDHCI_IO_ACCESSORS Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 12/68] mei: me: add denverton innovation engine device IDs Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 13/68] USB: serial: simple: add Motorola Tetra TPG2200 device id Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 14/68] USB: serial: pl2303: add new PID to support PL2303TB Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 15/68] ASoC: atom: fix a missing check of snd_pcm_lib_malloc_pages Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 16/68] ASoC: rt5514-spi: Fix potential NULL pointer dereference Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 17/68] ALSA: hda - Add mute LED support for HP ProBook 470 G5 Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 18/68] ARCv2: lib: memeset: fix doing prefetchw outside of buffer Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 19/68] ARC: adjust memblock_reserve of kernel memory Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 20/68] ARC: perf: map generic branches to correct hardware condition Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 21/68] s390/early: improve machine detection Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 22/68] s390/smp: fix CPU hotplug deadlock with CPU rescan Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 23/68] char/mwave: fix potential Spectre v1 vulnerability Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 24/68] staging: rtl8188eu: Add device code for D-Link DWA-121 rev B1 Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 25/68] tty: Handle problem if line discipline does not have receive_buf Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 26/68] uart: Fix crash in uart_write and uart_put_char Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 27/68] tty/n_hdlc: fix __might_sleep warning Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 28/68] hv_balloon: avoid touching uninitialized struct page during tail onlining Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 29/68] Drivers: hv: vmbus: Check for ring when getting debug info Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 30/68] CIFS: Fix possible hang during async MTU reads and writes Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 31/68] CIFS: Fix credits calculations for reads with errors Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 32/68] CIFS: Fix credit calculation for encrypted " Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 33/68] CIFS: Do not reconnect TCP session in add_credits() Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 34/68] Input: xpad - add support for SteelSeries Stratus Duo Greg Kroah-Hartman
2019-01-29 11:35 ` Greg Kroah-Hartman [this message]
2019-01-29 11:35 ` [PATCH 4.14 36/68] Input: uinput - fix undefined behavior in uinput_validate_absinfo() Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 37/68] acpi/nfit: Block function zero DSMs Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 38/68] acpi/nfit: Fix command-supported detection Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 39/68] dm thin: fix passdown_double_checking_shared_status() Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 40/68] dm crypt: fix parsing of extended IV arguments Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 41/68] KVM: x86: Fix single-step debugging Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 42/68] x86/pkeys: Properly copy pkey state at fork() Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 43/68] x86/selftests/pkeys: Fork() to check for state being preserved Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 44/68] x86/kaslr: Fix incorrect i8254 outb() parameters Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 45/68] posix-cpu-timers: Unbreak timer rearming Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 46/68] irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 47/68] can: dev: __can_get_echo_skb(): fix bogous check for non-existing skb by removing it Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 48/68] can: bcm: check timer values before ktime conversion Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 49/68] vt: invoke notifier on screen size change Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 50/68] perf unwind: Unwind with libdw doesnt take symfs into account Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 51/68] perf unwind: Take pgoff into account when reporting elf to libdwfl Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 52/68] Revert "seccomp: add a selftest for get_metadata" Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 53/68] net: stmmac: Use correct values in TQS/RQS fields Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 54/68] KVM: x86: Fix a 4.14 backport regression related to userspace/guest FPU Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 55/68] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 56/68] nvmet-rdma: Add unlikely for response allocated check Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 57/68] nvmet-rdma: fix null dereference under heavy load Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 58/68] usb: dwc3: gadget: Clear req->needs_extra_trb flag on cleanup Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 59/68] xhci: Fix leaking USB3 shared_hcd at xhci removal Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 60/68] ptp_kvm: probe for kvm guest availability Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 61/68] x86/pvclock: add setter for pvclock_pvti_cpu0_va Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 62/68] x86/xen/time: set pvclock flags on xen_time_init() Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 63/68] x86/xen/time: setup vcpu 0 time info page Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 64/68] x86/xen/time: Output xen sched_clock time from 0 Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 65/68] xen: Fix x86 sched_clock() interface for xen Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 66/68] f2fs: read page index before freeing Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 67/68] btrfs: fix error handling in btrfs_dev_replace_start Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 68/68] btrfs: dev-replace: go back to suspended state if target device is missing Greg Kroah-Hartman
2019-01-30  2:06 ` [PATCH 4.14 00/68] 4.14.97-stable review shuah
2019-01-30 12:51 ` Jon Hunter
2019-01-31  7:51   ` Greg Kroah-Hartman
2019-01-30 12:55 ` Naresh Kamboju
2019-01-30 18:49   ` Amir Goldstein
2019-01-30 19:32     ` Greg Kroah-Hartman
2019-02-04 10:12       ` Amir Goldstein
2019-02-04 10:35         ` Greg Kroah-Hartman
2019-01-30 22:13 ` Guenter Roeck

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LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git