x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't su

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot pos

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

[ Alexandre: SVM part. ]
[ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
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: conflicts at arch/x86/entry/entry_64_compat.S]
[cascardo: there is no ANNOTATE_NOENDBR]
[cascardo: objtool commit 34c861e806478ac2ea4032721defbf1d6967df08 missing]
[cascardo: conflict fixup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler.

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler. ]

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: CONFIG_STACK_VALIDATION vs CONFIG_OBJTOOL]
[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 ...

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't su

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot pos

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

[ Alexandre: SVM part. ]
[ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
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: conflicts at arch/x86/entry/entry_64_compat.S]
[cascardo: there is no ANNOTATE_NOENDBR]
[cascardo: objtool commit 34c861e806478ac2ea4032721defbf1d6967df08 missing]
[cascardo: conflict fixup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler.

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler. ]

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: CONFIG_STACK_VALIDATION vs CONFIG_OBJTOOL]
[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 ...

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't su

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot pos

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

[ Alexandre: SVM part. ]
[ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
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: conflicts at arch/x86/entry/entry_64_compat.S]
[cascardo: there is no ANNOTATE_NOENDBR]
[cascardo: objtool commit 34c861e806478ac2ea4032721defbf1d6967df08 missing]
[cascardo: conflict fixup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler.

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler. ]

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: CONFIG_STACK_VALIDATION vs CONFIG_OBJTOOL]
[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 ...

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't su

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot pos

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

[ Alexandre: SVM part. ]
[ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
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: conflicts at arch/x86/entry/entry_64_compat.S]
[cascardo: there is no ANNOTATE_NOENDBR]
[cascardo: objtool commit 34c861e806478ac2ea4032721defbf1d6967df08 missing]
[cascardo: conflict fixup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler.

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler. ]

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: CONFIG_STACK_VALIDATION vs CONFIG_OBJTOOL]
[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 ...

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't su

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot pos

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

[ Alexandre: SVM part. ]
[ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
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: conflicts at arch/x86/entry/entry_64_compat.S]
[cascardo: there is no ANNOTATE_NOENDBR]
[cascardo: objtool commit 34c861e806478ac2ea4032721defbf1d6967df08 missing]
[cascardo: conflict fixup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler.

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler. ]

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: CONFIG_STACK_VALIDATION vs CONFIG_OBJTOOL]
[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 ...

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't su

x86/retbleed: Add fine grained Kconfig knobs

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot pos

x86: Add magic AMD return-thunk

commit a149180fbcf336e97ce4eb2cdc13672727feb94d upstream.

Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

[ Alexandre: SVM part. ]
[ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
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: conflicts at arch/x86/entry/entry_64_compat.S]
[cascardo: there is no ANNOTATE_NOENDBR]
[cascardo: objtool commit 34c861e806478ac2ea4032721defbf1d6967df08 missing]
[cascardo: conflict fixup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler.

x86: Undo return-thunk damage

commit 15e67227c49a57837108acfe1c80570e1bd9f962 upstream.

Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.

[ bp: Do only INT3 padding - simpler. ]

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: CONFIG_STACK_VALIDATION vs CONFIG_OBJTOOL]
[cascardo: no IBT support]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlst

x86/retpoline: Cleanup some #ifdefery

commit 369ae6ffc41a3c1137cab697635a84d0cc7cdcea upstream.

On it's own not much of a cleanup but it prepares for more/similar
code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: conflict fixup because of DISABLE_ENQCMD]
[cascardo: no changes at nospec-branch.h and bpf_jit_comp.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...