6.6-stable patches

added patches:
	x86-speculation-objtool-use-absolute-relocations-for-annotations.patch

diff --git a/queue-6.6/series b/queue-6.6/series
index 9b3d5457558fcc28d1455a8196f4be7ceec697a9..a65ce66ed12ff89b28be76b4c874c270585dfdfa 100644 (file)
--- a/queue-6.6/series
+++ b/queue-6.6/series
@@ -162,3 +162,4 @@ ring-buffer-fix-writing-to-the-buffer-with-max_data_size.patch
 ring-buffer-fix-a-race-in-rb_time_cmpxchg-for-32-bit-archs.patch
 ring-buffer-do-not-try-to-put-back-write_stamp.patch
 ring-buffer-have-rb_time_cmpxchg-set-the-msb-counter-too.patch
+x86-speculation-objtool-use-absolute-relocations-for-annotations.patch

diff --git a/queue-6.6/x86-speculation-objtool-use-absolute-relocations-for-annotations.patch b/queue-6.6/x86-speculation-objtool-use-absolute-relocations-for-annotations.patch
new file mode 100644 (file)
index 0000000..b9b8df4
--- /dev/null
+++ b/queue-6.6/x86-speculation-objtool-use-absolute-relocations-for-annotations.patch
@@ -0,0 +1,131 @@
+From b8ec60e1186cdcfce41e7db4c827cb107e459002 Mon Sep 17 00:00:00 2001
+From: Fangrui Song <maskray@google.com>
+Date: Tue, 19 Sep 2023 17:17:28 -0700
+Subject: x86/speculation, objtool: Use absolute relocations for annotations
+
+From: Fangrui Song <maskray@google.com>
+
+commit b8ec60e1186cdcfce41e7db4c827cb107e459002 upstream.
+
+.discard.retpoline_safe sections do not have the SHF_ALLOC flag.  These
+sections referencing text sections' STT_SECTION symbols with PC-relative
+relocations like R_386_PC32 [0] is conceptually not suitable.  Newer
+LLD will report warnings for REL relocations even for relocatable links [1]:
+
+    ld.lld: warning: vmlinux.a(drivers/i2c/busses/i2c-i801.o):(.discard.retpoline_safe+0x120): has non-ABS relocation R_386_PC32 against symbol ''
+
+Switch to absolute relocations instead, which indicate link-time
+addresses.  In a relocatable link, these addresses are also output
+section offsets, used by checks in tools/objtool/check.c.  When linking
+vmlinux, these .discard.* sections will be discarded, therefore it is
+not a problem that R_X86_64_32 cannot represent a kernel address.
+
+Alternatively, we could set the SHF_ALLOC flag for .discard.* sections,
+but I think non-SHF_ALLOC for sections to be discarded makes more sense.
+
+Note: if we decide to never support REL architectures (e.g. arm, i386),
+we can utilize R_*_NONE relocations (.reloc ., BFD_RELOC_NONE, sym),
+making .discard.* sections zero-sized.  That said, the section content
+waste is 4 bytes per entry, much smaller than sizeof(Elf{32,64}_Rel).
+
+  [0] commit 1c0c1faf5692 ("objtool: Use relative pointers for annotations")
+  [1] https://github.com/ClangBuiltLinux/linux/issues/1937
+
+Signed-off-by: Fangrui Song <maskray@google.com>
+Signed-off-by: Ingo Molnar <mingo@kernel.org>
+Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Cc: Josh Poimboeuf <jpoimboe@redhat.com>
+Link: https://lore.kernel.org/r/20230920001728.1439947-1-maskray@google.com
+Cc: Nathan Chancellor <nathan@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/include/asm/alternative.h   |    4 ++--
+ arch/x86/include/asm/nospec-branch.h |    4 ++--
+ include/linux/objtool.h              |   10 +++++-----
+ 3 files changed, 9 insertions(+), 9 deletions(-)
+
+--- a/arch/x86/include/asm/alternative.h
++++ b/arch/x86/include/asm/alternative.h
+@@ -58,7 +58,7 @@
+ #define ANNOTATE_IGNORE_ALTERNATIVE                           \
+       "999:\n\t"                                              \
+       ".pushsection .discard.ignore_alts\n\t"                 \
+-      ".long 999b - .\n\t"                                    \
++      ".long 999b\n\t"                                        \
+       ".popsection\n\t"
+ 
+ /*
+@@ -352,7 +352,7 @@ static inline int alternatives_text_rese
+ .macro ANNOTATE_IGNORE_ALTERNATIVE
+       .Lannotate_\@:
+       .pushsection .discard.ignore_alts
+-      .long .Lannotate_\@ - .
++      .long .Lannotate_\@
+       .popsection
+ .endm
+ 
+--- a/arch/x86/include/asm/nospec-branch.h
++++ b/arch/x86/include/asm/nospec-branch.h
+@@ -196,7 +196,7 @@
+ .macro ANNOTATE_RETPOLINE_SAFE
+ .Lhere_\@:
+       .pushsection .discard.retpoline_safe
+-      .long .Lhere_\@ - .
++      .long .Lhere_\@
+       .popsection
+ .endm
+ 
+@@ -334,7 +334,7 @@
+ #define ANNOTATE_RETPOLINE_SAFE                                       \
+       "999:\n\t"                                              \
+       ".pushsection .discard.retpoline_safe\n\t"              \
+-      ".long 999b - .\n\t"                                    \
++      ".long 999b\n\t"                                        \
+       ".popsection\n\t"
+ 
+ typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
+--- a/include/linux/objtool.h
++++ b/include/linux/objtool.h
+@@ -48,13 +48,13 @@
+ #define ANNOTATE_NOENDBR                                      \
+       "986: \n\t"                                             \
+       ".pushsection .discard.noendbr\n\t"                     \
+-      ".long 986b - .\n\t"                                    \
++      ".long 986b\n\t"                                        \
+       ".popsection\n\t"
+ 
+ #define ASM_REACHABLE                                                 \
+       "998:\n\t"                                                      \
+       ".pushsection .discard.reachable\n\t"                           \
+-      ".long 998b - .\n\t"                                            \
++      ".long 998b\n\t"                                                \
+       ".popsection\n\t"
+ 
+ #else /* __ASSEMBLY__ */
+@@ -66,7 +66,7 @@
+ #define ANNOTATE_INTRA_FUNCTION_CALL                          \
+       999:                                                    \
+       .pushsection .discard.intra_function_calls;             \
+-      .long 999b - .;                                         \
++      .long 999b;                                             \
+       .popsection;
+ 
+ /*
+@@ -118,7 +118,7 @@
+ .macro ANNOTATE_NOENDBR
+ .Lhere_\@:
+       .pushsection .discard.noendbr
+-      .long   .Lhere_\@ - .
++      .long   .Lhere_\@
+       .popsection
+ .endm
+ 
+@@ -142,7 +142,7 @@
+ .macro REACHABLE
+ .Lhere_\@:
+       .pushsection .discard.reachable
+-      .long   .Lhere_\@ - .
++      .long   .Lhere_\@
+       .popsection
+ .endm
+