x86,objtool: Separate unret validation from unwind hints

The ENTRY unwind hint type is serving double duty as both an empty
unwind hint and an unret validation annotation.

Unret validation is unrel

x86,objtool: Separate unret validation from unwind hints

The ENTRY unwind hint type is serving double duty as both an empty
unwind hint and an unret validation annotation.

Unret validation is unrelated to unwinding. Separate it out into its own
annotation.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ff7448d492ea21b86d8a90264b105fbd0d751077.1677683419.git.jpoimboe@kernel.org

show more ...

objtool: Remove instruction::list

Replace the instruction::list by allocating instructions in arrays of
256 entries and stringing them together by (amortized) find_insn().
This shrinks instruction b

objtool: Remove instruction::list

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

show more ...

objtool: Union instruction::{call_dest,jump_table}

The instruction call_dest and jump_table members can never be used at
the same time, their usage depends on type.

struct instruction {
struct l

objtool: Union instruction::{call_dest,jump_table}

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

show more ...

objtool: Remove instruction::reloc

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

objtool: Remove instruction::reloc

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

show more ...

objtool: Shrink instruction::{type,visited}

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 i

objtool: Shrink instruction::{type,visited}

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

show more ...

objtool: Make instruction::alts a single-linked list

struct instruction {
struct list_head list; /* 0 16 */
struct hlist_node hash; /*

objtool: Make instruction::alts a single-linked list

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

show more ...

objtool: Make instruction::stack_ops a single-linked list

struct instruction {
struct list_head list; /* 0 16 */
struct hlist_node hash;

objtool: Make instruction::stack_ops a single-linked list

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

show more ...

objtool: Rework instruction -> symbol mapping

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 ins

objtool: Rework instruction -> symbol mapping

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>

show more ...

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

Commit

c536ed2fffd5 ("objtool: Remove SAVE/RESTORE hints")

removed the save/restore unwind hints because they were no longer
needed. Now they're going

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

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>

show more ...

objtool: Add entry UNRET validation

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 tho

objtool: Add entry UNRET validation

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>

show more ...

objtool: Read the NOENDBR annotation

Read the new NOENDBR annotation. While there, attempt to not bloat
struct instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jo

objtool: Read the NOENDBR annotation

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

show more ...

objtool: Shrink struct instruction

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruct

objtool: Shrink struct instruction

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruction, which is by far the most numerous
structure objtool creates.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.785456706@infradead.org

show more ...

objtool: Introduce CFI hash

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performance.

This is in part because we keep a struct instruction f

objtool: Introduce CFI hash

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performance.

This is in part because we keep a struct instruction for every
instruction in the file in-memory. Shrink struct instruction by
removing the CFI state (which includes full register state) from it
and demand allocating it.

Given most instructions don't actually change CFI state, there's lots
of repetition there, so add a hash table to find previous CFI
instances.

Reduces memory consumption (and runtime) for processing an
x86_64-allyesconfig:

pre: 4:40.84 real, 143.99 user, 44.18 sys, 30624988 mem
post: 2:14.61 real, 108.58 user, 25.04 sys, 16396184 mem

Suggested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095147.756759107@infradead.org

show more ...

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

Commit

c536ed2fffd5 ("objtool: Remove SAVE/RESTORE hints")

removed the save/restore unwind h

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

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>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Add entry UNRET validation

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done bef

objtool: Add entry UNRET validation

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

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>
[cascardo: tools/objtool/builtin-check.c no link option validation]
[cascardo: tools/objtool/check.c opts.ibt is ibt]
[cascardo: tools/objtool/include/objtool/builtin.h leave unret option as bool, no struct opts]
[cascardo: objtool is still called from scripts/link-vmlinux.sh]
[cascardo: no IBT support]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Introduce CFI hash

commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream.

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performan

objtool: Introduce CFI hash

commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream.

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performance.

This is in part because we keep a struct instruction for every
instruction in the file in-memory. Shrink struct instruction by
removing the CFI state (which includes full register state) from it
and demand allocating it.

Given most instructions don't actually change CFI state, there's lots
of repetition there, so add a hash table to find previous CFI
instances.

Reduces memory consumption (and runtime) for processing an
x86_64-allyesconfig:

pre: 4:40.84 real, 143.99 user, 44.18 sys, 30624988 mem
post: 2:14.61 real, 108.58 user, 25.04 sys, 16396184 mem

Suggested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095147.756759107@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Shrink struct instruction

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous

objtool: Shrink struct instruction

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruction, which is by far the most numerous
structure objtool creates.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.785456706@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

Commit

c536ed2fffd5 ("objtool: Remove SAVE/RESTORE hints")

removed the save/restore unwind h

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

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>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Add entry UNRET validation

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done bef

objtool: Add entry UNRET validation

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

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>
[cascardo: tools/objtool/builtin-check.c no link option validation]
[cascardo: tools/objtool/check.c opts.ibt is ibt]
[cascardo: tools/objtool/include/objtool/builtin.h leave unret option as bool, no struct opts]
[cascardo: objtool is still called from scripts/link-vmlinux.sh]
[cascardo: no IBT support]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Introduce CFI hash

commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream.

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performan

objtool: Introduce CFI hash

commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream.

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performance.

This is in part because we keep a struct instruction for every
instruction in the file in-memory. Shrink struct instruction by
removing the CFI state (which includes full register state) from it
and demand allocating it.

Given most instructions don't actually change CFI state, there's lots
of repetition there, so add a hash table to find previous CFI
instances.

Reduces memory consumption (and runtime) for processing an
x86_64-allyesconfig:

pre: 4:40.84 real, 143.99 user, 44.18 sys, 30624988 mem
post: 2:14.61 real, 108.58 user, 25.04 sys, 16396184 mem

Suggested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095147.756759107@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Shrink struct instruction

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous

objtool: Shrink struct instruction

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruction, which is by far the most numerous
structure objtool creates.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.785456706@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

Commit

c536ed2fffd5 ("objtool: Remove SAVE/RESTORE hints")

removed the save/restore unwind h

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

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>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Add entry UNRET validation

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done bef

objtool: Add entry UNRET validation

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

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>
[cascardo: tools/objtool/builtin-check.c no link option validation]
[cascardo: tools/objtool/check.c opts.ibt is ibt]
[cascardo: tools/objtool/include/objtool/builtin.h leave unret option as bool, no struct opts]
[cascardo: objtool is still called from scripts/link-vmlinux.sh]
[cascardo: no IBT support]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Introduce CFI hash

commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream.

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performan

objtool: Introduce CFI hash

commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream.

Andi reported that objtool on vmlinux.o consumes more memory than his
system has, leading to horrific performance.

This is in part because we keep a struct instruction for every
instruction in the file in-memory. Shrink struct instruction by
removing the CFI state (which includes full register state) from it
and demand allocating it.

Given most instructions don't actually change CFI state, there's lots
of repetition there, so add a hash table to find previous CFI
instances.

Reduces memory consumption (and runtime) for processing an
x86_64-allyesconfig:

pre: 4:40.84 real, 143.99 user, 44.18 sys, 30624988 mem
post: 2:14.61 real, 108.58 user, 25.04 sys, 16396184 mem

Suggested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095147.756759107@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

objtool: Shrink struct instruction

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous

objtool: Shrink struct instruction

commit c509331b41b7365e17396c246e8c5797bccc8074 upstream.

Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruction, which is by far the most numerous
structure objtool creates.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.785456706@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...