--- /dev/null
+From 459e3a21535ae3c7a9a123650e54f5c882b8fcbf Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Wed, 1 May 2019 11:20:53 -0700
+Subject: gcc-9: properly declare the {pv,hv}clock_page storage
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit 459e3a21535ae3c7a9a123650e54f5c882b8fcbf upstream.
+
+The pvlock_page and hvclock_page variables are (as the name implies)
+addresses to pages, created by the linker script.
+
+But we declared them as just "extern u8" variables, which _works_, but
+now that gcc does some more bounds checking, it causes warnings like
+
+ warning: array subscript 1 is outside array bounds of ‘u8[1]’
+
+when we then access more than one byte from those variables.
+
+Fix this by simply making the declaration of the variables match
+reality, which makes the compiler happy too.
+
+Signed-off-by: Linus Torvalds <torvalds@-linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/entry/vdso/vclock_gettime.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/arch/x86/entry/vdso/vclock_gettime.c
++++ b/arch/x86/entry/vdso/vclock_gettime.c
+@@ -29,12 +29,12 @@ extern int __vdso_gettimeofday(struct ti
+ extern time_t __vdso_time(time_t *t);
+
+ #ifdef CONFIG_PARAVIRT_CLOCK
+-extern u8 pvclock_page
++extern u8 pvclock_page[PAGE_SIZE]
+ __attribute__((visibility("hidden")));
+ #endif
+
+ #ifdef CONFIG_HYPERV_TSCPAGE
+-extern u8 hvclock_page
++extern u8 hvclock_page[PAGE_SIZE]
+ __attribute__((visibility("hidden")));
+ #endif
+
--- /dev/null
+From bcb6fb5da77c2a228adf07cc9cb1a0c2aa2001c6 Mon Sep 17 00:00:00 2001
+From: Josh Poimboeuf <jpoimboe@redhat.com>
+Date: Wed, 31 Oct 2018 21:57:30 -0500
+Subject: objtool: Support GCC 9 cold subfunction naming scheme
+
+From: Josh Poimboeuf <jpoimboe@redhat.com>
+
+commit bcb6fb5da77c2a228adf07cc9cb1a0c2aa2001c6 upstream.
+
+Starting with GCC 8, a lot of unlikely code was moved out of line to
+"cold" subfunctions in .text.unlikely.
+
+For example, the unlikely bits of:
+
+ irq_do_set_affinity()
+
+are moved out to the following subfunction:
+
+ irq_do_set_affinity.cold.49()
+
+Starting with GCC 9, the numbered suffix has been removed. So in the
+above example, the cold subfunction is instead:
+
+ irq_do_set_affinity.cold()
+
+Tweak the objtool subfunction detection logic so that it detects both
+GCC 8 and GCC 9 naming schemes.
+
+Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Link: https://lkml.kernel.org/r/015e9544b1f188d36a7f02fa31e9e95629aa5f50.1541040800.git.jpoimboe@redhat.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ tools/objtool/elf.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/tools/objtool/elf.c
++++ b/tools/objtool/elf.c
+@@ -305,7 +305,7 @@ static int read_symbols(struct elf *elf)
+ if (sym->type != STT_FUNC)
+ continue;
+ sym->pfunc = sym->cfunc = sym;
+- coldstr = strstr(sym->name, ".cold.");
++ coldstr = strstr(sym->name, ".cold");
+ if (!coldstr)
+ continue;
+
ib-mlx5-fix-rss-toeplitz-setup-to-be-aligned-with-the-hw-specification.patch
ib-hfi1-check-for-error-on-call-to-alloc_rsm_map_table.patch
eeprom-at24-make-spd-world-readable-again.patch
+objtool-support-gcc-9-cold-subfunction-naming-scheme.patch
+gcc-9-properly-declare-the-pv-hv-clock_page-storage.patch
+x86-vdso-prevent-segfaults-due-to-hoisted-vclock-reads.patch
--- /dev/null
+From ff17bbe0bb405ad8b36e55815d381841f9fdeebc Mon Sep 17 00:00:00 2001
+From: Andy Lutomirski <luto@kernel.org>
+Date: Fri, 21 Jun 2019 08:43:04 -0700
+Subject: x86/vdso: Prevent segfaults due to hoisted vclock reads
+
+From: Andy Lutomirski <luto@kernel.org>
+
+commit ff17bbe0bb405ad8b36e55815d381841f9fdeebc upstream.
+
+GCC 5.5.0 sometimes cleverly hoists reads of the pvclock and/or hvclock
+pages before the vclock mode checks. This creates a path through
+vclock_gettime() in which no vclock is enabled at all (due to disabled
+TSC on old CPUs, for example) but the pvclock or hvclock page
+nevertheless read. This will segfault on bare metal.
+
+This fixes commit 459e3a21535a ("gcc-9: properly declare the
+{pv,hv}clock_page storage") in the sense that, before that commit, GCC
+didn't seem to generate the offending code. There was nothing wrong
+with that commit per se, and -stable maintainers should backport this to
+all supported kernels regardless of whether the offending commit was
+present, since the same crash could just as easily be triggered by the
+phase of the moon.
+
+On GCC 9.1.1, this doesn't seem to affect the generated code at all, so
+I'm not too concerned about performance regressions from this fix.
+
+Cc: stable@vger.kernel.org
+Cc: x86@kernel.org
+Cc: Borislav Petkov <bp@alien8.de>
+Reported-by: Duncan Roe <duncan_roe@optusnet.com.au>
+Signed-off-by: Andy Lutomirski <luto@kernel.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/entry/vdso/vclock_gettime.c | 15 +++++++++++++--
+ 1 file changed, 13 insertions(+), 2 deletions(-)
+
+--- a/arch/x86/entry/vdso/vclock_gettime.c
++++ b/arch/x86/entry/vdso/vclock_gettime.c
+@@ -191,13 +191,24 @@ notrace static inline u64 vgetsns(int *m
+
+ if (gtod->vclock_mode == VCLOCK_TSC)
+ cycles = vread_tsc();
++
++ /*
++ * For any memory-mapped vclock type, we need to make sure that gcc
++ * doesn't cleverly hoist a load before the mode check. Otherwise we
++ * might end up touching the memory-mapped page even if the vclock in
++ * question isn't enabled, which will segfault. Hence the barriers.
++ */
+ #ifdef CONFIG_PARAVIRT_CLOCK
+- else if (gtod->vclock_mode == VCLOCK_PVCLOCK)
++ else if (gtod->vclock_mode == VCLOCK_PVCLOCK) {
++ barrier();
+ cycles = vread_pvclock(mode);
++ }
+ #endif
+ #ifdef CONFIG_HYPERV_TSCPAGE
+- else if (gtod->vclock_mode == VCLOCK_HVCLOCK)
++ else if (gtod->vclock_mode == VCLOCK_HVCLOCK) {
++ barrier();
+ cycles = vread_hvclock(mode);
++ }
+ #endif
+ else
+ return 0;
projects / thirdparty / kernel / stable-queue.git / commitdiff
