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2023-02-23objtool: Fix ORC 'signal' propagationJosh Poimboeuf1-0/+1
There have been some recently reported ORC unwinder warnings like: WARNING: can't access registers at entry_SYSCALL_64_after_hwframe+0x63/0xcd WARNING: stack going in the wrong direction? at __sys_setsockopt+0x2c6/0x5b0 net/socket.c:2271 And a KASAN warning: BUG: KASAN: stack-out-of-bounds in unwind_next_frame (arch/x86/include/asm/ptrace.h:136 arch/x86/kernel/unwind_orc.c:455) It turns out the 'signal' bit isn't getting propagated from the unwind hints to the ORC entries, making the unwinder confused at times. Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") Reported-by: kernel test robot <oliver.sang@intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/97eef9db60cd86d376a9a40d49d77bb67a8f6526.1676579666.git.jpoimboe@kernel.org
2023-02-23objtool: Remove instruction::listPeter Zijlstra2-25/+27
Replace the instruction::list by allocating instructions in arrays of 256 entries and stringing them together by (amortized) find_insn(). This shrinks instruction by 16 bytes and brings it down to 128. struct instruction { - struct list_head list; /* 0 16 */ - struct hlist_node hash; /* 16 16 */ - struct list_head call_node; /* 32 16 */ - struct section * sec; /* 48 8 */ - long unsigned int offset; /* 56 8 */ - /* --- cacheline 1 boundary (64 bytes) --- */ - long unsigned int immediate; /* 64 8 */ - unsigned int len; /* 72 4 */ - u8 type; /* 76 1 */ - - /* Bitfield combined with previous fields */ + struct hlist_node hash; /* 0 16 */ + struct list_head call_node; /* 16 16 */ + struct section * sec; /* 32 8 */ + long unsigned int offset; /* 40 8 */ + long unsigned int immediate; /* 48 8 */ + u8 len; /* 56 1 */ + u8 prev_len; /* 57 1 */ + u8 type; /* 58 1 */ + s8 instr; /* 59 1 */ + u32 idx:8; /* 60: 0 4 */ + u32 dead_end:1; /* 60: 8 4 */ + u32 ignore:1; /* 60: 9 4 */ + u32 ignore_alts:1; /* 60:10 4 */ + u32 hint:1; /* 60:11 4 */ + u32 save:1; /* 60:12 4 */ + u32 restore:1; /* 60:13 4 */ + u32 retpoline_safe:1; /* 60:14 4 */ + u32 noendbr:1; /* 60:15 4 */ + u32 entry:1; /* 60:16 4 */ + u32 visited:4; /* 60:17 4 */ + u32 no_reloc:1; /* 60:21 4 */ - u16 dead_end:1; /* 76: 8 2 */ - u16 ignore:1; /* 76: 9 2 */ - u16 ignore_alts:1; /* 76:10 2 */ - u16 hint:1; /* 76:11 2 */ - u16 save:1; /* 76:12 2 */ - u16 restore:1; /* 76:13 2 */ - u16 retpoline_safe:1; /* 76:14 2 */ - u16 noendbr:1; /* 76:15 2 */ - u16 entry:1; /* 78: 0 2 */ - u16 visited:4; /* 78: 1 2 */ - u16 no_reloc:1; /* 78: 5 2 */ + /* XXX 10 bits hole, try to pack */ - /* XXX 2 bits hole, try to pack */ - /* Bitfield combined with next fields */ - - s8 instr; /* 79 1 */ - struct alt_group * alt_group; /* 80 8 */ - struct instruction * jump_dest; /* 88 8 */ - struct instruction * first_jump_src; /* 96 8 */ + /* --- cacheline 1 boundary (64 bytes) --- */ + struct alt_group * alt_group; /* 64 8 */ + struct instruction * jump_dest; /* 72 8 */ + struct instruction * first_jump_src; /* 80 8 */ union { - struct symbol * _call_dest; /* 104 8 */ - struct reloc * _jump_table; /* 104 8 */ - }; /* 104 8 */ - struct alternative * alts; /* 112 8 */ - struct symbol * sym; /* 120 8 */ - /* --- cacheline 2 boundary (128 bytes) --- */ - struct stack_op * stack_ops; /* 128 8 */ - struct cfi_state * cfi; /* 136 8 */ + struct symbol * _call_dest; /* 88 8 */ + struct reloc * _jump_table; /* 88 8 */ + }; /* 88 8 */ + struct alternative * alts; /* 96 8 */ + struct symbol * sym; /* 104 8 */ + struct stack_op * stack_ops; /* 112 8 */ + struct cfi_state * cfi; /* 120 8 */ - /* size: 144, cachelines: 3, members: 28 */ - /* sum members: 142 */ - /* sum bitfield members: 14 bits, bit holes: 1, sum bit holes: 2 bits */ - /* last cacheline: 16 bytes */ + /* size: 128, cachelines: 2, members: 29 */ + /* sum members: 124 */ + /* sum bitfield members: 22 bits, bit holes: 1, sum bit holes: 10 bits */ }; pre: 5:38.18 real, 213.25 user, 124.90 sys, 23449040 mem post: 5:03.34 real, 210.75 user, 88.80 sys, 20241232 mem Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.851307606@infradead.org
2023-02-23objtool: Union instruction::{call_dest,jump_table}Peter Zijlstra1-2/+4
The instruction call_dest and jump_table members can never be used at the same time, their usage depends on type. struct instruction { struct list_head list; /* 0 16 */ struct hlist_node hash; /* 16 16 */ struct list_head call_node; /* 32 16 */ struct section * sec; /* 48 8 */ long unsigned int offset; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ long unsigned int immediate; /* 64 8 */ unsigned int len; /* 72 4 */ u8 type; /* 76 1 */ /* Bitfield combined with previous fields */ u16 dead_end:1; /* 76: 8 2 */ u16 ignore:1; /* 76: 9 2 */ u16 ignore_alts:1; /* 76:10 2 */ u16 hint:1; /* 76:11 2 */ u16 save:1; /* 76:12 2 */ u16 restore:1; /* 76:13 2 */ u16 retpoline_safe:1; /* 76:14 2 */ u16 noendbr:1; /* 76:15 2 */ u16 entry:1; /* 78: 0 2 */ u16 visited:4; /* 78: 1 2 */ u16 no_reloc:1; /* 78: 5 2 */ /* XXX 2 bits hole, try to pack */ /* Bitfield combined with next fields */ s8 instr; /* 79 1 */ struct alt_group * alt_group; /* 80 8 */ - struct symbol * call_dest; /* 88 8 */ - struct instruction * jump_dest; /* 96 8 */ - struct instruction * first_jump_src; /* 104 8 */ - struct reloc * jump_table; /* 112 8 */ - struct alternative * alts; /* 120 8 */ + struct instruction * jump_dest; /* 88 8 */ + struct instruction * first_jump_src; /* 96 8 */ + union { + struct symbol * _call_dest; /* 104 8 */ + struct reloc * _jump_table; /* 104 8 */ + }; /* 104 8 */ + struct alternative * alts; /* 112 8 */ + struct symbol * sym; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ - struct symbol * sym; /* 128 8 */ - struct stack_op * stack_ops; /* 136 8 */ - struct cfi_state * cfi; /* 144 8 */ + struct stack_op * stack_ops; /* 128 8 */ + struct cfi_state * cfi; /* 136 8 */ - /* size: 152, cachelines: 3, members: 29 */ - /* sum members: 150 */ + /* size: 144, cachelines: 3, members: 28 */ + /* sum members: 142 */ /* sum bitfield members: 14 bits, bit holes: 1, sum bit holes: 2 bits */ - /* last cacheline: 24 bytes */ + /* last cacheline: 16 bytes */ }; pre: 5:39.35 real, 215.58 user, 123.69 sys, 23448736 mem post: 5:38.18 real, 213.25 user, 124.90 sys, 23449040 mem Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.640914454@infradead.org
2023-02-23objtool: Remove instruction::relocPeter Zijlstra1-3/+3
Instead of caching the reloc for each instruction, only keep a negative cache of not having a reloc (by far the most common case). struct instruction { struct list_head list; /* 0 16 */ struct hlist_node hash; /* 16 16 */ struct list_head call_node; /* 32 16 */ struct section * sec; /* 48 8 */ long unsigned int offset; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ long unsigned int immediate; /* 64 8 */ unsigned int len; /* 72 4 */ u8 type; /* 76 1 */ /* Bitfield combined with previous fields */ u16 dead_end:1; /* 76: 8 2 */ u16 ignore:1; /* 76: 9 2 */ u16 ignore_alts:1; /* 76:10 2 */ u16 hint:1; /* 76:11 2 */ u16 save:1; /* 76:12 2 */ u16 restore:1; /* 76:13 2 */ u16 retpoline_safe:1; /* 76:14 2 */ u16 noendbr:1; /* 76:15 2 */ u16 entry:1; /* 78: 0 2 */ u16 visited:4; /* 78: 1 2 */ + u16 no_reloc:1; /* 78: 5 2 */ - /* XXX 3 bits hole, try to pack */ + /* XXX 2 bits hole, try to pack */ /* Bitfield combined with next fields */ s8 instr; /* 79 1 */ struct alt_group * alt_group; /* 80 8 */ struct symbol * call_dest; /* 88 8 */ struct instruction * jump_dest; /* 96 8 */ struct instruction * first_jump_src; /* 104 8 */ struct reloc * jump_table; /* 112 8 */ - struct reloc * reloc; /* 120 8 */ + struct alternative * alts; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ - struct alternative * alts; /* 128 8 */ - struct symbol * sym; /* 136 8 */ - struct stack_op * stack_ops; /* 144 8 */ - struct cfi_state * cfi; /* 152 8 */ + struct symbol * sym; /* 128 8 */ + struct stack_op * stack_ops; /* 136 8 */ + struct cfi_state * cfi; /* 144 8 */ - /* size: 160, cachelines: 3, members: 29 */ - /* sum members: 158 */ - /* sum bitfield members: 13 bits, bit holes: 1, sum bit holes: 3 bits */ - /* last cacheline: 32 bytes */ + /* size: 152, cachelines: 3, members: 29 */ + /* sum members: 150 */ + /* sum bitfield members: 14 bits, bit holes: 1, sum bit holes: 2 bits */ + /* last cacheline: 24 bytes */ }; pre: 5:48.89 real, 220.96 user, 127.55 sys, 24834672 mem post: 5:39.35 real, 215.58 user, 123.69 sys, 23448736 mem Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.572145269@infradead.org
2023-02-23objtool: Shrink instruction::{type,visited}Peter Zijlstra1-5/+5
Since we don't have that many types in enum insn_type, force it into a u8 and re-arrange member to get rid of the holes, saves another 8 bytes. struct instruction { struct list_head list; /* 0 16 */ struct hlist_node hash; /* 16 16 */ struct list_head call_node; /* 32 16 */ struct section * sec; /* 48 8 */ long unsigned int offset; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ - unsigned int len; /* 64 4 */ - enum insn_type type; /* 68 4 */ - long unsigned int immediate; /* 72 8 */ - u16 dead_end:1; /* 80: 0 2 */ - u16 ignore:1; /* 80: 1 2 */ - u16 ignore_alts:1; /* 80: 2 2 */ - u16 hint:1; /* 80: 3 2 */ - u16 save:1; /* 80: 4 2 */ - u16 restore:1; /* 80: 5 2 */ - u16 retpoline_safe:1; /* 80: 6 2 */ - u16 noendbr:1; /* 80: 7 2 */ - u16 entry:1; /* 80: 8 2 */ + long unsigned int immediate; /* 64 8 */ + unsigned int len; /* 72 4 */ + u8 type; /* 76 1 */ - /* XXX 7 bits hole, try to pack */ + /* Bitfield combined with previous fields */ - s8 instr; /* 82 1 */ - u8 visited; /* 83 1 */ + u16 dead_end:1; /* 76: 8 2 */ + u16 ignore:1; /* 76: 9 2 */ + u16 ignore_alts:1; /* 76:10 2 */ + u16 hint:1; /* 76:11 2 */ + u16 save:1; /* 76:12 2 */ + u16 restore:1; /* 76:13 2 */ + u16 retpoline_safe:1; /* 76:14 2 */ + u16 noendbr:1; /* 76:15 2 */ + u16 entry:1; /* 78: 0 2 */ + u16 visited:4; /* 78: 1 2 */ - /* XXX 4 bytes hole, try to pack */ + /* XXX 3 bits hole, try to pack */ + /* Bitfield combined with next fields */ - struct alt_group * alt_group; /* 88 8 */ - struct symbol * call_dest; /* 96 8 */ - struct instruction * jump_dest; /* 104 8 */ - struct instruction * first_jump_src; /* 112 8 */ - struct reloc * jump_table; /* 120 8 */ + s8 instr; /* 79 1 */ + struct alt_group * alt_group; /* 80 8 */ + struct symbol * call_dest; /* 88 8 */ + struct instruction * jump_dest; /* 96 8 */ + struct instruction * first_jump_src; /* 104 8 */ + struct reloc * jump_table; /* 112 8 */ + struct reloc * reloc; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ - struct reloc * reloc; /* 128 8 */ - struct alternative * alts; /* 136 8 */ - struct symbol * sym; /* 144 8 */ - struct stack_op * stack_ops; /* 152 8 */ - struct cfi_state * cfi; /* 160 8 */ + struct alternative * alts; /* 128 8 */ + struct symbol * sym; /* 136 8 */ + struct stack_op * stack_ops; /* 144 8 */ + struct cfi_state * cfi; /* 152 8 */ - /* size: 168, cachelines: 3, members: 29 */ - /* sum members: 162, holes: 1, sum holes: 4 */ - /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 7 bits */ - /* last cacheline: 40 bytes */ + /* size: 160, cachelines: 3, members: 29 */ + /* sum members: 158 */ + /* sum bitfield members: 13 bits, bit holes: 1, sum bit holes: 3 bits */ + /* last cacheline: 32 bytes */ }; pre: 5:48.86 real, 220.30 user, 128.34 sys, 24834672 mem post: 5:48.89 real, 220.96 user, 127.55 sys, 24834672 mem Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.501847188@infradead.org
2023-02-23objtool: Make instruction::alts a single-linked listPeter Zijlstra1-1/+1
struct instruction { struct list_head list; /* 0 16 */ struct hlist_node hash; /* 16 16 */ struct list_head call_node; /* 32 16 */ struct section * sec; /* 48 8 */ long unsigned int offset; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ unsigned int len; /* 64 4 */ enum insn_type type; /* 68 4 */ long unsigned int immediate; /* 72 8 */ u16 dead_end:1; /* 80: 0 2 */ u16 ignore:1; /* 80: 1 2 */ u16 ignore_alts:1; /* 80: 2 2 */ u16 hint:1; /* 80: 3 2 */ u16 save:1; /* 80: 4 2 */ u16 restore:1; /* 80: 5 2 */ u16 retpoline_safe:1; /* 80: 6 2 */ u16 noendbr:1; /* 80: 7 2 */ u16 entry:1; /* 80: 8 2 */ /* XXX 7 bits hole, try to pack */ s8 instr; /* 82 1 */ u8 visited; /* 83 1 */ /* XXX 4 bytes hole, try to pack */ struct alt_group * alt_group; /* 88 8 */ struct symbol * call_dest; /* 96 8 */ struct instruction * jump_dest; /* 104 8 */ struct instruction * first_jump_src; /* 112 8 */ struct reloc * jump_table; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ struct reloc * reloc; /* 128 8 */ - struct list_head alts; /* 136 16 */ - struct symbol * sym; /* 152 8 */ - struct stack_op * stack_ops; /* 160 8 */ - struct cfi_state * cfi; /* 168 8 */ + struct alternative * alts; /* 136 8 */ + struct symbol * sym; /* 144 8 */ + struct stack_op * stack_ops; /* 152 8 */ + struct cfi_state * cfi; /* 160 8 */ - /* size: 176, cachelines: 3, members: 29 */ - /* sum members: 170, holes: 1, sum holes: 4 */ + /* size: 168, cachelines: 3, members: 29 */ + /* sum members: 162, holes: 1, sum holes: 4 */ /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 7 bits */ - /* last cacheline: 48 bytes */ + /* last cacheline: 40 bytes */ }; pre: 5:58.50 real, 229.64 user, 128.65 sys, 26221520 mem post: 5:48.86 real, 220.30 user, 128.34 sys, 24834672 mem Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.430556498@infradead.org
2023-02-23objtool: Make instruction::stack_ops a single-linked listPeter Zijlstra2-2/+2
struct instruction { struct list_head list; /* 0 16 */ struct hlist_node hash; /* 16 16 */ struct list_head call_node; /* 32 16 */ struct section * sec; /* 48 8 */ long unsigned int offset; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ unsigned int len; /* 64 4 */ enum insn_type type; /* 68 4 */ long unsigned int immediate; /* 72 8 */ u16 dead_end:1; /* 80: 0 2 */ u16 ignore:1; /* 80: 1 2 */ u16 ignore_alts:1; /* 80: 2 2 */ u16 hint:1; /* 80: 3 2 */ u16 save:1; /* 80: 4 2 */ u16 restore:1; /* 80: 5 2 */ u16 retpoline_safe:1; /* 80: 6 2 */ u16 noendbr:1; /* 80: 7 2 */ u16 entry:1; /* 80: 8 2 */ /* XXX 7 bits hole, try to pack */ s8 instr; /* 82 1 */ u8 visited; /* 83 1 */ /* XXX 4 bytes hole, try to pack */ struct alt_group * alt_group; /* 88 8 */ struct symbol * call_dest; /* 96 8 */ struct instruction * jump_dest; /* 104 8 */ struct instruction * first_jump_src; /* 112 8 */ struct reloc * jump_table; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ struct reloc * reloc; /* 128 8 */ struct list_head alts; /* 136 16 */ struct symbol * sym; /* 152 8 */ - struct list_head stack_ops; /* 160 16 */ - struct cfi_state * cfi; /* 176 8 */ + struct stack_op * stack_ops; /* 160 8 */ + struct cfi_state * cfi; /* 168 8 */ - /* size: 184, cachelines: 3, members: 29 */ - /* sum members: 178, holes: 1, sum holes: 4 */ + /* size: 176, cachelines: 3, members: 29 */ + /* sum members: 170, holes: 1, sum holes: 4 */ /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 7 bits */ - /* last cacheline: 56 bytes */ + /* last cacheline: 48 bytes */ }; pre: 5:58.22 real, 226.69 user, 131.22 sys, 26221520 mem post: 5:58.50 real, 229.64 user, 128.65 sys, 26221520 mem Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.362196959@infradead.org
2023-02-23objtool: Change arch_decode_instruction() signaturePeter Zijlstra1-3/+1
In preparation to changing struct instruction around a bit, avoid passing it's members by pointer and instead pass the whole thing. A cleanup in it's own right too. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> # build only Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run Link: https://lore.kernel.org/r/20230208172245.291087549@infradead.org
2023-02-01objtool: Optimize layout of struct special_altThomas Weißschuh1-1/+1
Reduce the size of struct special_alt from 72 to 64 bytes. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-7-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Optimize layout of struct symbolThomas Weißschuh1-3/+2
Reduce the size of struct symbol on x86_64 from 208 to 200 bytes. This structure is allocated a lot and never freed. This reduces maximum memory usage while processing vmlinux.o from 2919716 KB to 2917988 KB (-0.5%) on my notebooks "localmodconfig". Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-6-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Allocate multiple structures with calloc()Thomas Weißschuh1-0/+4
By using calloc() instead of malloc() in a loop, libc does not have to keep around bookkeeping information for each single structure. This reduces maximum memory usage while processing vmlinux.o from 3153325 KB to 3035668 KB (-3.7%) on my notebooks "localmodconfig". Note this introduces memory leaks, because some additional structs get added to the lists later after reading the symbols and sections from the original object. Luckily we don't really care about memory leaks in objtool. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-3-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Make struct check_options staticThomas Weißschuh1-2/+0
It is not used outside of builtin-check.c. Also remove the unused declaration from builtin.h . Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-2-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2022-12-19Merge tag 'powerpc-6.2-1' of ↵Linus Torvalds4-16/+27
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Add powerpc qspinlock implementation optimised for large system scalability and paravirt. See the merge message for more details - Enable objtool to be built on powerpc to generate mcount locations - Use a temporary mm for code patching with the Radix MMU, so the writable mapping is restricted to the patching CPU - Add an option to build the 64-bit big-endian kernel with the ELFv2 ABI - Sanitise user registers on interrupt entry on 64-bit Book3S - Many other small features and fixes Thanks to Aboorva Devarajan, Angel Iglesias, Benjamin Gray, Bjorn Helgaas, Bo Liu, Chen Lifu, Christoph Hellwig, Christophe JAILLET, Christophe Leroy, Christopher M. Riedl, Colin Ian King, Deming Wang, Disha Goel, Dmitry Torokhov, Finn Thain, Geert Uytterhoeven, Gustavo A. R. Silva, Haowen Bai, Joel Stanley, Jordan Niethe, Julia Lawall, Kajol Jain, Laurent Dufour, Li zeming, Miaoqian Lin, Michael Jeanson, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Miehlbradt, Nicholas Piggin, Pali Rohár, Randy Dunlap, Rohan McLure, Russell Currey, Sathvika Vasireddy, Shaomin Deng, Stephen Kitt, Stephen Rothwell, Thomas Weißschuh, Tiezhu Yang, Uwe Kleine-König, Xie Shaowen, Xiu Jianfeng, XueBing Chen, Yang Yingliang, Zhang Jiaming, ruanjinjie, Jessica Yu, and Wolfram Sang. * tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (181 commits) powerpc/code-patching: Fix oops with DEBUG_VM enabled powerpc/qspinlock: Fix 32-bit build powerpc/prom: Fix 32-bit build powerpc/rtas: mandate RTAS syscall filtering powerpc/rtas: define pr_fmt and convert printk call sites powerpc/rtas: clean up includes powerpc/rtas: clean up rtas_error_log_max initialization powerpc/pseries/eeh: use correct API for error log size powerpc/rtas: avoid scheduling in rtas_os_term() powerpc/rtas: avoid device tree lookups in rtas_os_term() powerpc/rtasd: use correct OF API for event scan rate powerpc/rtas: document rtas_call() powerpc/pseries: unregister VPA when hot unplugging a CPU powerpc/pseries: reset the RCU watchdogs after a LPM powerpc: Take in account addition CPU node when building kexec FDT powerpc: export the CPU node count powerpc/cpuidle: Set CPUIDLE_FLAG_POLLING for snooze state powerpc/dts/fsl: Fix pca954x i2c-mux node names cxl: Remove unnecessary cxl_pci_window_alignment() selftests/powerpc: Fix resource leaks ...
2022-11-23objtool/powerpc: Implement arch_pc_relative_reloc()Michael Ellerman1-0/+2
Provide an implementation for arch_pc_relative_reloc(). It is needed to pass the build once 61c6065ef7ec ("objtool: Allow !PC relative relocations") is merged. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2022-11-18objtool: Add arch specific function arch_ftrace_match()Sathvika Vasireddy1-0/+2
Add architecture specific function to look for relocation records pointing to architecture specific symbols. Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-15-sv@linux.ibm.com
2022-11-18objtool: Add --mnop as an option to --mcountSathvika Vasireddy1-0/+1
Some architectures (powerpc) may not support ftrace locations being nop'ed out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as a means for architectures to enable nop'ing of ftrace locations. Add --mnop as an option to objtool --mcount, to indicate support for the same. Also, make sure that --mnop can be passed as an option to objtool only when --mcount is passed. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-12-sv@linux.ibm.com
2022-11-18objtool: Use target file class size instead of a compiled constantChristophe Leroy1-0/+8
In order to allow using objtool on cross-built kernels, determine size of long from elf data instead of using sizeof(long) at build time. For the time being this covers only mcount. [Sathvika Vasireddy: Rename variable "size" to "addrsize" and function "elf_class_size()" to "elf_class_addrsize()", and modify create_mcount_loc_sections() function to follow reverse christmas tree format to order local variable declarations.] Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-11-sv@linux.ibm.com
2022-11-18objtool: Use target file endianness instead of a compiled constantChristophe Leroy1-16/+16
Some architectures like powerpc support both endianness, it's therefore not possible to fix the endianness via arch/endianness.h because there is no easy way to get the target endianness at build time. Use the endianness recorded in the file objtool is working on. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-10-sv@linux.ibm.com
2022-11-05objtool: Optimize elf_dirty_reloc_sym()Peter Zijlstra1-0/+2
When moving a symbol in the symtab its index changes and any reloc referring that symtol-table-index will need to be rewritten too. In order to facilitate this, objtool simply marks the whole reloc section 'changed' which will cause the whole section to be re-generated. However, finding the relocs that use any given symbol is implemented rather crudely -- a fully iteration of all sections and their relocs. Given that some builds have over 20k sections (kallsyms etc..) iterating all that for *each* symbol moved takes a bit of time. Instead have each symbol keep a list of relocs that reference it. This *vastly* improves build times for certain configs. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Y2LlRA7x+8UsE1xf@hirez.programming.kicks-ass.net
2022-11-01objtool: Add --cfi to generate the .cfi_sites sectionPeter Zijlstra1-0/+1
Add the location of all __cfi_##name symbols (as generated by kCFI) to a section such that we might re-write things at kernel boot. Notably; boot time re-hashing and FineIBT are the intended use of this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20221027092842.568039454@infradead.org
2022-11-01objtool: Add option to generate prefix symbolsPeter Zijlstra2-0/+3
When code is compiled with: -fpatchable-function-entry=${PADDING_BYTES},${PADDING_BYTES} functions will have PADDING_BYTES of NOP in front of them. Unwinders and other things that symbolize code locations will typically attribute these bytes to the preceding function. Given that these bytes nominally belong to the following symbol this mis-attribution is confusing. Inspired by the fact that CFI_CLANG emits __cfi_##name symbols to claim these bytes, allow objtool to emit __pfx_##name symbols to do the same. Therefore add the objtool --prefix=N argument, to conditionally place a __pfx_##name symbol at N bytes ahead of symbol 'name' when: all these preceding bytes are NOP and name-N is an instruction boundary. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yujie Liu <yujie.liu@intel.com> Link: https://lkml.kernel.org/r/20221028194453.526899822@infradead.org
2022-11-01objtool: Avoid O(bloody terrible) behaviour -- an ode to libelfPeter Zijlstra1-1/+1
Due to how gelf_update_sym*() requires an Elf_Data pointer, and how libelf keeps Elf_Data in a linked list per section, elf_update_symbol() ends up having to iterate this list on each update to find the correct Elf_Data for the index'ed symbol. By allocating one Elf_Data per new symbol, the list grows per new symbol, giving an effective O(n^2) insertion time. This is obviously bloody terrible. Therefore over-allocate the Elf_Data when an extention is needed. Except it turns out libelf disregards Elf_Scn::sh_size in favour of the sum of Elf_Data::d_size. IOW it will happily write out all the unused space and fill it with: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND entries (aka zeros). Which obviously violates the STB_LOCAL placement rule, and is a general pain in the backside for not being the desired behaviour. Manually fix-up the Elf_Data size to avoid this problem before calling elf_update(). This significantly improves performance when adding a significant number of symbols. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yujie Liu <yujie.liu@intel.com> Link: https://lkml.kernel.org/r/20221028194453.461658986@infradead.org
2022-10-17objtool: Rework instruction -> symbol mappingPeter Zijlstra1-1/+11
Currently insn->func contains a instruction -> symbol link for STT_FUNC symbols. A NULL value is assumed to mean STT_NOTYPE. However, there are also instructions not covered by any symbol at all. This can happen due to __weak symbols for example. Since the current scheme cannot differentiate between no symbol and STT_NOTYPE symbol, change things around. Make insn->sym point to any symbol type such that !insn->sym means no symbol and add a helper insn_func() that check the sym->type to retain the old functionality. This then prepares the way to add code that depends on the distinction between STT_NOTYPE and no symbol at all. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-10-17objtool: Fix find_{symbol,func}_containing()Peter Zijlstra1-1/+2
The current find_{symbol,func}_containing() functions are broken in the face of overlapping symbols, exactly the case that is needed for a new ibt/endbr supression. Import interval_tree_generic.h into the tools tree and convert the symbol tree to an interval tree to support proper range stabs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.330203761@infradead.org
2022-10-17objtool: Add --hacks=skylakePeter Zijlstra1-0/+1
Make the call/func sections selectable via the --hacks option. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.120821440@infradead.org
2022-10-17objtool: Add .call_sites sectionPeter Zijlstra1-0/+1
In preparation for call depth tracking provide a section which collects all direct calls. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.016511961@infradead.org
2022-10-17objtool: Track init sectionPeter Zijlstra1-1/+1
For future usage of .init.text exclusion track the init section in the instruction decoder and use the result in retpoline validation. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.910334431@infradead.org
2022-10-17objtool: Allow !PC relative relocationsPeter Zijlstra1-0/+2
Objtool doesn't currently much like per-cpu usage in alternatives: arch/x86/entry/entry_64.o: warning: objtool: .altinstr_replacement+0xf: unsupported relocation in alternatives section f: 65 c7 04 25 00 00 00 00 00 00 00 80 movl $0x80000000,%gs:0x0 13: R_X86_64_32S __x86_call_depth Since the R_X86_64_32S relocation is location invariant (it's computation doesn't include P - the address of the location itself), it can be trivially allowed. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.806607235@infradead.org
2022-06-29x86/retbleed: Add fine grained Kconfig knobsPeter Zijlstra1-0/+1
Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}Josh Poimboeuf1-9/+10
Commit c536ed2fffd5 ("objtool: Remove SAVE/RESTORE hints") removed the save/restore unwind hints because they were no longer needed. Now they're going to be needed again so re-add them. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27objtool: Add entry UNRET validationPeter Zijlstra2-2/+10
Since entry asm is tricky, add a validation pass that ensures the retbleed mitigation has been done before the first actual RET instruction. Entry points are those that either have UNWIND_HINT_ENTRY, which acts as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or those that have UWIND_HINT_IRET_REGS at +0. This is basically a variant of validate_branch() that is intra-function and it will simply follow all branches from marked entry points and ensures that all paths lead to ANNOTATE_UNRET_END. If a path hits RET or an indirection the path is a fail and will be reported. There are 3 ANNOTATE_UNRET_END instances: - UNTRAIN_RET itself - exception from-kernel; this path doesn't need UNTRAIN_RET - all early exceptions; these also don't need UNTRAIN_RET Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27x86,objtool: Create .return_sitesPeter Zijlstra3-0/+3
Find all the return-thunk sites and record them in a .return_sites section such that the kernel can undo this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-05-20objtool: Fix objtool regression on x32 systemsMikulas Patocka1-2/+2
Commit c087c6e7b551 ("objtool: Fix type of reloc::addend") failed to appreciate cross building from ILP32 hosts, where 'int' == 'long' and the issue persists. As such, use s64/int64_t/Elf64_Sxword for this field and suffer the pain that is ISO C99 printf formats for it. Fixes: c087c6e7b551 ("objtool: Fix type of reloc::addend") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> [peterz: reword changelog, s/long long/s64/] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2205161041260.11556@file01.intranet.prod.int.rdu2.redhat.com
2022-04-22objtool: Remove --lto and --vmlinux in favor of --linkJosh Poimboeuf2-3/+12
The '--lto' option is a confusing way of telling objtool to do stack validation despite it being a linked object. It's no longer needed now that an explicit '--stackval' option exists. The '--vmlinux' option is also redundant. Remove both options in favor of a straightforward '--link' option which identifies a linked object. Also, implicitly set '--link' with a warning if the user forgets to do so and we can tell that it's a linked object. This makes it easier for manual vmlinux runs. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/dcd3ceffd15a54822c6183e5766d21ad06082b45.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Make noinstr hacks optionalJosh Poimboeuf1-0/+1
Objtool has some hacks in place to workaround toolchain limitations which otherwise would break no-instrumentation rules. Make the hacks explicit (and optional for other arches) by turning it into a cmdline option and kernel config option. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/b326eeb9c33231b9dfbb925f194ed7ee40edcd7c.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Make jump label hack optionalJosh Poimboeuf1-0/+1
Objtool secretly does a jump label hack to overcome the limitations of the toolchain. Make the hack explicit (and optional for other arches) by turning it into a cmdline option and kernel config option. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/3bdcbfdd27ecb01ddec13c04bdf756a583b13d24.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Make static call annotation optionalJosh Poimboeuf1-0/+1
As part of making objtool more modular, put the existing static call code behind a new '--static-call' option. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/d59ac57ef3d6d8380cdce20322314c9e2e556750.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Make stack validation frame-pointer-specificJosh Poimboeuf1-1/+0
Now that CONFIG_STACK_VALIDATION is frame-pointer specific, do the same for the '--stackval' option. Now the '--no-fp' option is redundant and can be removed. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/f563fa064b3b63d528de250c72012d49e14742a3.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Make stack validation optionalJosh Poimboeuf1-0/+1
Make stack validation an explicit cmdline option so that individual objtool features can be enabled individually by other arches. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/52da143699574d756e65ca4c9d4acaffe9b0fe5f.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Add option to print section addressesJosh Poimboeuf2-14/+18
To help prevent objtool users from having to do math to convert function addresses to section addresses, and to help out with finding data addresses reported by IBT validation, add an option to print the section address in addition to the function address. Normal: vmlinux.o: warning: objtool: fixup_exception()+0x2d1: unreachable instruction With '--sec-address': vmlinux.o: warning: objtool: fixup_exception()+0x2d1 (.text+0x76c51): unreachable instruction Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/2cea4d5299d53d1a4c09212a6ad7820aa46fda7a.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Don't print parentheses in function addressesJosh Poimboeuf1-5/+1
The parentheses in the "func()+off" address output are inconsistent with how the kernel prints function addresses, breaking Peter's scripts. Remove them. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/f2bec70312f62ef4f1ea21c134d9def627182ad3.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Ditch subcommandsJosh Poimboeuf1-2/+3
Objtool has a fairly singular focus. It runs on object files and does validations and transformations which can be combined in various ways. The subcommand model has never been a good fit, making it awkward to combine and remove options. Remove the "check" and "orc" subcommands in favor of a more traditional cmdline option model. This makes it much more flexible to use, and easier to port individual features to other arches. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/5c61ebf805e90aefc5fa62bc63468ffae53b9df6.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Reorganize cmdline optionsJosh Poimboeuf1-3/+23
Split the existing options into two groups: actions, which actually do something; and options, which modify the actions in some way. Also there's no need to have short flags for all the non-action options. Reserve short flags for the more important actions. While at it: - change a few of the short flags to be more intuitive - make option descriptions more consistently descriptive - sort options in the source like they are when printed - move options to a global struct Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/9dcaa752f83aca24b1b21f0b0eeb28a0c181c0b0.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Fix type of reloc::addendPeter Zijlstra1-2/+2
Elf{32,64}_Rela::r_addend is of type: Elf{32,64}_Sword, that means that our reloc::addend needs to be long or face tuncation issues when we do elf_rebuild_reloc_section(): - 107: 48 b8 00 00 00 00 00 00 00 00 movabs $0x0,%rax 109: R_X86_64_64 level4_kernel_pgt+0x80000067 + 107: 48 b8 00 00 00 00 00 00 00 00 movabs $0x0,%rax 109: R_X86_64_64 level4_kernel_pgt-0x7fffff99 Fixes: 627fce14809b ("objtool: Add ORC unwind table generation") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20220419203807.596871927@infradead.org
2022-04-19objtool: Fix function fallthrough detection for vmlinuxJosh Poimboeuf1-1/+1
Objtool's function fallthrough detection only works on C objects. The distinction between C and assembly objects no longer makes sense with objtool running on vmlinux.o. Now that copy_user_64.S has been fixed up, and an objtool sibling call detection bug has been fixed, the asm code is in "compliance" and this hack is no longer needed. Remove it. Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/b434cff98eca3a60dcc64c620d7d5d405a0f441c.1649718562.git.jpoimboe@redhat.com
2022-03-15objtool: Find unused ENDBR instructionsPeter Zijlstra1-0/+1
Find all ENDBR instructions which are never referenced and stick them in a section such that the kernel can poison them, sealing the functions from ever being an indirect call target. This removes about 1-in-4 ENDBR instructions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.763643193@infradead.org
2022-03-15objtool: Validate IBT assumptionsPeter Zijlstra2-1/+5
Intel IBT requires that every indirect JMP/CALL targets an ENDBR instructions, failing this #CP happens and we die. Similarly, all exception entries should be ENDBR. Find all code relocations and ensure they're either an ENDBR instruction or ANNOTATE_NOENDBR. For the exceptions look for UNWIND_HINT_IRET_REGS at sym+0 not being ENDBR. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.705110141@infradead.org
2022-03-15objtool: Add IBT/ENDBR decodingPeter Zijlstra1-0/+1
Intel IBT requires the target of any indirect CALL or JMP instruction to be the ENDBR instruction; optionally it allows those two instructions to have a NOTRACK prefix in order to avoid this requirement. The kernel will not enable the use of NOTRACK, as such any occurence of it in compiler generated code should be flagged. Teach objtool to Decode ENDBR instructions and WARN about NOTRACK prefixes. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.645963517@infradead.org
2022-03-15objtool: Read the NOENDBR annotationPeter Zijlstra1-3/+10
Read the new NOENDBR annotation. While there, attempt to not bloat struct instruction. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.586815435@infradead.org
2022-03-15objtool: Ignore extra-symbol codePeter Zijlstra1-0/+1
There's a fun implementation detail on linking STB_WEAK symbols. When the linker combines two translation units, where one contains a weak function and the other an override for it. It simply strips the STB_WEAK symbol from the symbol table, but doesn't actually remove the code. The result is that when objtool is ran in a whole-archive kind of way, it will encounter *heaps* of unused (and unreferenced) code. All rudiments of weak functions. Additionally, when a weak implementation is split into a .cold subfunction that .cold symbol is left in place, even though completely unused. Teach objtool to ignore such rudiments by searching for symbol holes; that is, code ranges that fall outside the given symbol bounds. Specifically, ignore a sequence of unreachable instruction iff they occupy a single hole, additionally ignore any .cold subfunctions referenced. Both ld.bfd and ld.lld behave like this. LTO builds otoh can (and do) properly DCE weak functions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.232019347@infradead.org