Otherwise, we see warnings like this:
[ 0.000000][ T0] ------------[ cut here ]------------ [ 0.000000][ T0] unexpected static_call insn opcode 0xf at kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/static_call.c:88 __static_call_validate+0x68/0x70 [ 0.000000][ T0] Modules linked in: [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.151-00083-gf200c7260296 #68 fe3cb25cf78cb710722bb5acd1cadddd35172924 [ 0.000000][ T0] RIP: 0010:__static_call_validate+0x68/0x70 [ 0.000000][ T0] Code: 0f b6 4a 04 81 f1 c0 00 00 00 09 c1 74 cc 80 3d be 2c 02 02 00 75 c3 c6 05 b5 2c 02 02 01 48 c7 c7 38 4f c3 82 e8 e8 c8 09 00 <0f> 0b c3 00 00 cc cc 00 53 48 89 fb 48 63 15 31 71 06 02 e8 b0 b8 [ 0.000000][ T0] RSP: 0000:ffffffff82e03e70 EFLAGS: 00010046 ORIG_RAX: 0000000000000000 [ 0.000000][ T0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 0.000000][ T0] RDX: 0000000000000000 RSI: ffffffff82e03ce0 RDI: 0000000000000001 [ 0.000000][ T0] RBP: 0000000000000001 R08: 00000000ffffffff R09: ffffffff82eaab70 [ 0.000000][ T0] R10: ffffffff82e2e900 R11: 205d305420202020 R12: ffffffff82e51960 [ 0.000000][ T0] R13: ffffffff81038987 R14: ffffffff81038987 R15: 0000000000000001 [ 0.000000][ T0] FS: 0000000000000000(0000) GS:ffffffff83726000(0000) knlGS:0000000000000000 [ 0.000000][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.000000][ T0] CR2: ffff888000014be8 CR3: 00000000037b2000 CR4: 00000000000000a0 [ 0.000000][ T0] Call Trace: [ 0.000000][ T0] <TASK> [ 0.000000][ T0] ? __warn+0x75/0xe0 [ 0.000000][ T0] ? report_bug+0x81/0xe0 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? early_fixup_exception+0x44/0xa0 [ 0.000000][ T0] ? early_idt_handler_common+0x2f/0x40 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? __static_call_validate+0x68/0x70 [ 0.000000][ T0] ? arch_static_call_transform+0x5c/0x90 [ 0.000000][ T0] ? __static_call_init+0x1ec/0x230 [ 0.000000][ T0] ? static_call_init+0x32/0x70 [ 0.000000][ T0] ? setup_arch+0x36/0x4f0 [ 0.000000][ T0] ? start_kernel+0x67/0x400 [ 0.000000][ T0] ? secondary_startup_64_no_verify+0xb1/0xbb [ 0.000000][ T0] </TASK> [ 0.000000][ T0] ---[ end trace 8c8589c01f370686 ]---
Peter Zijlstra (3): x86/alternatives: Introduce int3_emulate_jcc() x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions x86/static_call: Add support for Jcc tail-calls
arch/x86/include/asm/text-patching.h | 31 +++++++++++++++ arch/x86/kernel/alternative.c | 56 +++++++++++++++++++++++----- arch/x86/kernel/kprobes/core.c | 38 ++++--------------- arch/x86/kernel/static_call.c | 49 ++++++++++++++++++++++-- 4 files changed, 132 insertions(+), 42 deletions(-)
From: Peter Zijlstra peterz@infradead.org
commit db7adcfd1cec4e95155e37bc066fddab302c6340 upstream.
Move the kprobe Jcc emulation into int3_emulate_jcc() so it can be used by more code -- specifically static_call() will need this.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Masami Hiramatsu (Google) mhiramat@kernel.org Link: https://lore.kernel.org/r/20230123210607.057678245@infradead.org Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@igalia.com --- arch/x86/include/asm/text-patching.h | 31 +++++++++++++++++++++++ arch/x86/kernel/kprobes/core.c | 38 ++++++---------------------- 2 files changed, 39 insertions(+), 30 deletions(-)
diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index c6015b407461..7281ce64e99d 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -181,6 +181,37 @@ void int3_emulate_ret(struct pt_regs *regs) unsigned long ip = int3_emulate_pop(regs); int3_emulate_jmp(regs, ip); } + +static __always_inline +void int3_emulate_jcc(struct pt_regs *regs, u8 cc, unsigned long ip, unsigned long disp) +{ + static const unsigned long jcc_mask[6] = { + [0] = X86_EFLAGS_OF, + [1] = X86_EFLAGS_CF, + [2] = X86_EFLAGS_ZF, + [3] = X86_EFLAGS_CF | X86_EFLAGS_ZF, + [4] = X86_EFLAGS_SF, + [5] = X86_EFLAGS_PF, + }; + + bool invert = cc & 1; + bool match; + + if (cc < 0xc) { + match = regs->flags & jcc_mask[cc >> 1]; + } else { + match = ((regs->flags & X86_EFLAGS_SF) >> X86_EFLAGS_SF_BIT) ^ + ((regs->flags & X86_EFLAGS_OF) >> X86_EFLAGS_OF_BIT); + if (cc >= 0xe) + match = match || (regs->flags & X86_EFLAGS_ZF); + } + + if ((match && !invert) || (!match && invert)) + ip += disp; + + int3_emulate_jmp(regs, ip); +} + #endif /* !CONFIG_UML_X86 */
#endif /* _ASM_X86_TEXT_PATCHING_H */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 052ea7425c4d..893f040b97b7 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -463,50 +463,26 @@ static void kprobe_emulate_call(struct kprobe *p, struct pt_regs *regs) } NOKPROBE_SYMBOL(kprobe_emulate_call);
-static nokprobe_inline -void __kprobe_emulate_jmp(struct kprobe *p, struct pt_regs *regs, bool cond) +static void kprobe_emulate_jmp(struct kprobe *p, struct pt_regs *regs) { unsigned long ip = regs->ip - INT3_INSN_SIZE + p->ainsn.size;
- if (cond) - ip += p->ainsn.rel32; + ip += p->ainsn.rel32; int3_emulate_jmp(regs, ip); } - -static void kprobe_emulate_jmp(struct kprobe *p, struct pt_regs *regs) -{ - __kprobe_emulate_jmp(p, regs, true); -} NOKPROBE_SYMBOL(kprobe_emulate_jmp);
-static const unsigned long jcc_mask[6] = { - [0] = X86_EFLAGS_OF, - [1] = X86_EFLAGS_CF, - [2] = X86_EFLAGS_ZF, - [3] = X86_EFLAGS_CF | X86_EFLAGS_ZF, - [4] = X86_EFLAGS_SF, - [5] = X86_EFLAGS_PF, -}; - static void kprobe_emulate_jcc(struct kprobe *p, struct pt_regs *regs) { - bool invert = p->ainsn.jcc.type & 1; - bool match; + unsigned long ip = regs->ip - INT3_INSN_SIZE + p->ainsn.size;
- if (p->ainsn.jcc.type < 0xc) { - match = regs->flags & jcc_mask[p->ainsn.jcc.type >> 1]; - } else { - match = ((regs->flags & X86_EFLAGS_SF) >> X86_EFLAGS_SF_BIT) ^ - ((regs->flags & X86_EFLAGS_OF) >> X86_EFLAGS_OF_BIT); - if (p->ainsn.jcc.type >= 0xe) - match = match || (regs->flags & X86_EFLAGS_ZF); - } - __kprobe_emulate_jmp(p, regs, (match && !invert) || (!match && invert)); + int3_emulate_jcc(regs, p->ainsn.jcc.type, ip, p->ainsn.rel32); } NOKPROBE_SYMBOL(kprobe_emulate_jcc);
static void kprobe_emulate_loop(struct kprobe *p, struct pt_regs *regs) { + unsigned long ip = regs->ip - INT3_INSN_SIZE + p->ainsn.size; bool match;
if (p->ainsn.loop.type != 3) { /* LOOP* */ @@ -534,7 +510,9 @@ static void kprobe_emulate_loop(struct kprobe *p, struct pt_regs *regs) else if (p->ainsn.loop.type == 1) /* LOOPE */ match = match && (regs->flags & X86_EFLAGS_ZF);
- __kprobe_emulate_jmp(p, regs, match); + if (match) + ip += p->ainsn.rel32; + int3_emulate_jmp(regs, ip); } NOKPROBE_SYMBOL(kprobe_emulate_loop);
From: Peter Zijlstra peterz@infradead.org
commit ac0ee0a9560c97fa5fe1409e450c2425d4ebd17a upstream.
In order to re-write Jcc.d32 instructions text_poke_bp() needs to be taught about them.
The biggest hurdle is that the whole machinery is currently made for 5 byte instructions and extending this would grow struct text_poke_loc which is currently a nice 16 bytes and used in an array.
However, since text_poke_loc contains a full copy of the (s32) displacement, it is possible to map the Jcc.d32 2 byte opcodes to Jcc.d8 1 byte opcode for the int3 emulation.
This then leaves the replacement bytes; fudge that by only storing the last 5 bytes and adding the rule that 'length == 6' instruction will be prefixed with a 0x0f byte.
Change-Id: Ie3f72c6b92f865d287c8940e5a87e59d41cfaa27 Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Masami Hiramatsu (Google) mhiramat@kernel.org Link: https://lore.kernel.org/r/20230123210607.115718513@infradead.org [cascardo: there is no emit_call_track_retpoline] Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@igalia.com --- arch/x86/kernel/alternative.c | 56 +++++++++++++++++++++++++++++------ 1 file changed, 47 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index e5536edbae57..5614e6d219b7 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -351,6 +351,12 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, kasan_enable_current(); }
+static inline bool is_jcc32(struct insn *insn) +{ + /* Jcc.d32 second opcode byte is in the range: 0x80-0x8f */ + return insn->opcode.bytes[0] == 0x0f && (insn->opcode.bytes[1] & 0xf0) == 0x80; +} + #if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION)
/* @@ -1201,6 +1207,11 @@ void text_poke_sync(void) on_each_cpu(do_sync_core, NULL, 1); }
+/* + * NOTE: crazy scheme to allow patching Jcc.d32 but not increase the size of + * this thing. When len == 6 everything is prefixed with 0x0f and we map + * opcode to Jcc.d8, using len to distinguish. + */ struct text_poke_loc { /* addr := _stext + rel_addr */ s32 rel_addr; @@ -1322,6 +1333,10 @@ noinstr int poke_int3_handler(struct pt_regs *regs) int3_emulate_jmp(regs, (long)ip + tp->disp); break;
+ case 0x70 ... 0x7f: /* Jcc */ + int3_emulate_jcc(regs, tp->opcode & 0xf, (long)ip, tp->disp); + break; + default: BUG(); } @@ -1395,16 +1410,26 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries * Second step: update all but the first byte of the patched range. */ for (do_sync = 0, i = 0; i < nr_entries; i++) { - u8 old[POKE_MAX_OPCODE_SIZE] = { tp[i].old, }; + u8 old[POKE_MAX_OPCODE_SIZE+1] = { tp[i].old, }; + u8 _new[POKE_MAX_OPCODE_SIZE+1]; + const u8 *new = tp[i].text; int len = tp[i].len;
if (len - INT3_INSN_SIZE > 0) { memcpy(old + INT3_INSN_SIZE, text_poke_addr(&tp[i]) + INT3_INSN_SIZE, len - INT3_INSN_SIZE); + + if (len == 6) { + _new[0] = 0x0f; + memcpy(_new + 1, new, 5); + new = _new; + } + text_poke(text_poke_addr(&tp[i]) + INT3_INSN_SIZE, - (const char *)tp[i].text + INT3_INSN_SIZE, + new + INT3_INSN_SIZE, len - INT3_INSN_SIZE); + do_sync++; }
@@ -1432,8 +1457,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries * The old instruction is recorded so that the event can be * processed forwards or backwards. */ - perf_event_text_poke(text_poke_addr(&tp[i]), old, len, - tp[i].text, len); + perf_event_text_poke(text_poke_addr(&tp[i]), old, len, new, len); }
if (do_sync) { @@ -1450,10 +1474,15 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries * replacing opcode. */ for (do_sync = 0, i = 0; i < nr_entries; i++) { - if (tp[i].text[0] == INT3_INSN_OPCODE) + u8 byte = tp[i].text[0]; + + if (tp[i].len == 6) + byte = 0x0f; + + if (byte == INT3_INSN_OPCODE) continue;
- text_poke(text_poke_addr(&tp[i]), tp[i].text, INT3_INSN_SIZE); + text_poke(text_poke_addr(&tp[i]), &byte, INT3_INSN_SIZE); do_sync++; }
@@ -1471,9 +1500,11 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr, const void *opcode, size_t len, const void *emulate) { struct insn insn; - int ret, i; + int ret, i = 0;
- memcpy((void *)tp->text, opcode, len); + if (len == 6) + i = 1; + memcpy((void *)tp->text, opcode+i, len-i); if (!emulate) emulate = opcode;
@@ -1484,6 +1515,13 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr, tp->len = len; tp->opcode = insn.opcode.bytes[0];
+ if (is_jcc32(&insn)) { + /* + * Map Jcc.d32 onto Jcc.d8 and use len to distinguish. + */ + tp->opcode = insn.opcode.bytes[1] - 0x10; + } + switch (tp->opcode) { case RET_INSN_OPCODE: case JMP32_INSN_OPCODE: @@ -1500,7 +1538,6 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr, BUG_ON(len != insn.length); };
- switch (tp->opcode) { case INT3_INSN_OPCODE: case RET_INSN_OPCODE: @@ -1509,6 +1546,7 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr, case CALL_INSN_OPCODE: case JMP32_INSN_OPCODE: case JMP8_INSN_OPCODE: + case 0x70 ... 0x7f: /* Jcc */ tp->disp = insn.immediate.value; break;
From: Peter Zijlstra peterz@infradead.org
commit 923510c88d2b7d947c4217835fd9ca6bd65cc56c upstream.
Clang likes to create conditional tail calls like:
0000000000000350 <amd_pmu_add_event>: 350: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 351: R_X86_64_NONE __fentry__-0x4 355: 48 83 bf 20 01 00 00 00 cmpq $0x0,0x120(%rdi) 35d: 0f 85 00 00 00 00 jne 363 <amd_pmu_add_event+0x13> 35f: R_X86_64_PLT32 __SCT__amd_pmu_branch_add-0x4 363: e9 00 00 00 00 jmp 368 <amd_pmu_add_event+0x18> 364: R_X86_64_PLT32 __x86_return_thunk-0x4
Where 0x35d is a static call site that's turned into a conditional tail-call using the Jcc class of instructions.
Teach the in-line static call text patching about this.
Notably, since there is no conditional-ret, in that case patch the Jcc to point at an empty stub function that does the ret -- or the return thunk when needed.
Reported-by: "Erhard F." erhard_f@mailbox.org Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Masami Hiramatsu (Google) mhiramat@kernel.org Link: https://lore.kernel.org/r/Y9Kdg9QjHkr9G5b5@hirez.programming.kicks-ass.net [nathan: Backport to 6.1: - Use __x86_return_thunk instead of x86_return_thunk for func in __static_call_transform() - Remove ASM_FUNC_ALIGN in __static_call_return() asm, as call depth tracking was merged in 6.2] Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [cascardo: __static_call_validate didn't have the bool tramp argument] Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@igalia.com --- arch/x86/kernel/static_call.c | 49 ++++++++++++++++++++++++++++++++--- 1 file changed, 46 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c index e25050c7ff1e..94378f202c50 100644 --- a/arch/x86/kernel/static_call.c +++ b/arch/x86/kernel/static_call.c @@ -9,6 +9,7 @@ enum insn_type { NOP = 1, /* site cond-call */ JMP = 2, /* tramp / site tail-call */ RET = 3, /* tramp / site cond-tail-call */ + JCC = 4, };
/* @@ -25,12 +26,39 @@ static const u8 xor5rax[] = { 0x2e, 0x2e, 0x2e, 0x31, 0xc0 };
static const u8 retinsn[] = { RET_INSN_OPCODE, 0xcc, 0xcc, 0xcc, 0xcc };
+static u8 __is_Jcc(u8 *insn) /* Jcc.d32 */ +{ + u8 ret = 0; + + if (insn[0] == 0x0f) { + u8 tmp = insn[1]; + if ((tmp & 0xf0) == 0x80) + ret = tmp; + } + + return ret; +} + +extern void __static_call_return(void); + +asm (".global __static_call_return\n\t" + ".type __static_call_return, @function\n\t" + "__static_call_return:\n\t" + ANNOTATE_NOENDBR + ANNOTATE_RETPOLINE_SAFE + "ret; int3\n\t" + ".size __static_call_return, . - __static_call_return \n\t"); + static void __ref __static_call_transform(void *insn, enum insn_type type, void *func, bool modinit) { const void *emulate = NULL; int size = CALL_INSN_SIZE; const void *code; + u8 op, buf[6]; + + if ((type == JMP || type == RET) && (op = __is_Jcc(insn))) + type = JCC;
switch (type) { case CALL: @@ -56,6 +84,20 @@ static void __ref __static_call_transform(void *insn, enum insn_type type, else code = &retinsn; break; + + case JCC: + if (!func) { + func = __static_call_return; + if (cpu_feature_enabled(X86_FEATURE_RETHUNK)) + func = __x86_return_thunk; + } + + buf[0] = 0x0f; + __text_gen_insn(buf+1, op, insn+1, func, 5); + code = buf; + size = 6; + + break; }
if (memcmp(insn, code, size) == 0) @@ -67,13 +109,14 @@ static void __ref __static_call_transform(void *insn, enum insn_type type, text_poke_bp(insn, code, size, emulate); }
-static void __static_call_validate(void *insn, bool tail) +static void __static_call_validate(u8 *insn, bool tail) { - u8 opcode = *(u8 *)insn; + u8 opcode = insn[0];
if (tail) { if (opcode == JMP32_INSN_OPCODE || - opcode == RET_INSN_OPCODE) + opcode == RET_INSN_OPCODE || + __is_Jcc(insn)) return; } else { if (opcode == CALL_INSN_OPCODE ||
On Mon, Mar 18, 2024 at 10:39:04AM -0300, Thadeu Lima de Souza Cascardo wrote:
Otherwise, we see warnings like this:
[ 0.000000][ T0] ------------[ cut here ]------------ [ 0.000000][ T0] unexpected static_call insn opcode 0xf at kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/static_call.c:88 __static_call_validate+0x68/0x70 [ 0.000000][ T0] Modules linked in: [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.151-00083-gf200c7260296 #68 fe3cb25cf78cb710722bb5acd1cadddd35172924 [ 0.000000][ T0] RIP: 0010:__static_call_validate+0x68/0x70 [ 0.000000][ T0] Code: 0f b6 4a 04 81 f1 c0 00 00 00 09 c1 74 cc 80 3d be 2c 02 02 00 75 c3 c6 05 b5 2c 02 02 01 48 c7 c7 38 4f c3 82 e8 e8 c8 09 00 <0f> 0b c3 00 00 cc cc 00 53 48 89 fb 48 63 15 31 71 06 02 e8 b0 b8 [ 0.000000][ T0] RSP: 0000:ffffffff82e03e70 EFLAGS: 00010046 ORIG_RAX: 0000000000000000 [ 0.000000][ T0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 0.000000][ T0] RDX: 0000000000000000 RSI: ffffffff82e03ce0 RDI: 0000000000000001 [ 0.000000][ T0] RBP: 0000000000000001 R08: 00000000ffffffff R09: ffffffff82eaab70 [ 0.000000][ T0] R10: ffffffff82e2e900 R11: 205d305420202020 R12: ffffffff82e51960 [ 0.000000][ T0] R13: ffffffff81038987 R14: ffffffff81038987 R15: 0000000000000001 [ 0.000000][ T0] FS: 0000000000000000(0000) GS:ffffffff83726000(0000) knlGS:0000000000000000 [ 0.000000][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.000000][ T0] CR2: ffff888000014be8 CR3: 00000000037b2000 CR4: 00000000000000a0 [ 0.000000][ T0] Call Trace: [ 0.000000][ T0] <TASK> [ 0.000000][ T0] ? __warn+0x75/0xe0 [ 0.000000][ T0] ? report_bug+0x81/0xe0 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? early_fixup_exception+0x44/0xa0 [ 0.000000][ T0] ? early_idt_handler_common+0x2f/0x40 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? __static_call_validate+0x68/0x70 [ 0.000000][ T0] ? arch_static_call_transform+0x5c/0x90 [ 0.000000][ T0] ? __static_call_init+0x1ec/0x230 [ 0.000000][ T0] ? static_call_init+0x32/0x70 [ 0.000000][ T0] ? setup_arch+0x36/0x4f0 [ 0.000000][ T0] ? start_kernel+0x67/0x400 [ 0.000000][ T0] ? secondary_startup_64_no_verify+0xb1/0xbb [ 0.000000][ T0] </TASK> [ 0.000000][ T0] ---[ end trace 8c8589c01f370686 ]---
Peter Zijlstra (3): x86/alternatives: Introduce int3_emulate_jcc() x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions x86/static_call: Add support for Jcc tail-calls
arch/x86/include/asm/text-patching.h | 31 +++++++++++++++ arch/x86/kernel/alternative.c | 56 +++++++++++++++++++++++----- arch/x86/kernel/kprobes/core.c | 38 ++++--------------- arch/x86/kernel/static_call.c | 49 ++++++++++++++++++++++-- 4 files changed, 132 insertions(+), 42 deletions(-)
Why is there a v2 series here? Are the ones I just took not correct?
confused,
greg k-h
On Fri, Mar 29, 2024 at 01:50:11PM +0100, Greg KH wrote:
On Mon, Mar 18, 2024 at 10:39:04AM -0300, Thadeu Lima de Souza Cascardo wrote:
Otherwise, we see warnings like this:
[ 0.000000][ T0] ------------[ cut here ]------------ [ 0.000000][ T0] unexpected static_call insn opcode 0xf at kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/static_call.c:88 __static_call_validate+0x68/0x70 [ 0.000000][ T0] Modules linked in: [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.151-00083-gf200c7260296 #68 fe3cb25cf78cb710722bb5acd1cadddd35172924 [ 0.000000][ T0] RIP: 0010:__static_call_validate+0x68/0x70 [ 0.000000][ T0] Code: 0f b6 4a 04 81 f1 c0 00 00 00 09 c1 74 cc 80 3d be 2c 02 02 00 75 c3 c6 05 b5 2c 02 02 01 48 c7 c7 38 4f c3 82 e8 e8 c8 09 00 <0f> 0b c3 00 00 cc cc 00 53 48 89 fb 48 63 15 31 71 06 02 e8 b0 b8 [ 0.000000][ T0] RSP: 0000:ffffffff82e03e70 EFLAGS: 00010046 ORIG_RAX: 0000000000000000 [ 0.000000][ T0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 0.000000][ T0] RDX: 0000000000000000 RSI: ffffffff82e03ce0 RDI: 0000000000000001 [ 0.000000][ T0] RBP: 0000000000000001 R08: 00000000ffffffff R09: ffffffff82eaab70 [ 0.000000][ T0] R10: ffffffff82e2e900 R11: 205d305420202020 R12: ffffffff82e51960 [ 0.000000][ T0] R13: ffffffff81038987 R14: ffffffff81038987 R15: 0000000000000001 [ 0.000000][ T0] FS: 0000000000000000(0000) GS:ffffffff83726000(0000) knlGS:0000000000000000 [ 0.000000][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.000000][ T0] CR2: ffff888000014be8 CR3: 00000000037b2000 CR4: 00000000000000a0 [ 0.000000][ T0] Call Trace: [ 0.000000][ T0] <TASK> [ 0.000000][ T0] ? __warn+0x75/0xe0 [ 0.000000][ T0] ? report_bug+0x81/0xe0 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? early_fixup_exception+0x44/0xa0 [ 0.000000][ T0] ? early_idt_handler_common+0x2f/0x40 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? __static_call_validate+0x68/0x70 [ 0.000000][ T0] ? arch_static_call_transform+0x5c/0x90 [ 0.000000][ T0] ? __static_call_init+0x1ec/0x230 [ 0.000000][ T0] ? static_call_init+0x32/0x70 [ 0.000000][ T0] ? setup_arch+0x36/0x4f0 [ 0.000000][ T0] ? start_kernel+0x67/0x400 [ 0.000000][ T0] ? secondary_startup_64_no_verify+0xb1/0xbb [ 0.000000][ T0] </TASK> [ 0.000000][ T0] ---[ end trace 8c8589c01f370686 ]---
Peter Zijlstra (3): x86/alternatives: Introduce int3_emulate_jcc() x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions x86/static_call: Add support for Jcc tail-calls
arch/x86/include/asm/text-patching.h | 31 +++++++++++++++ arch/x86/kernel/alternative.c | 56 +++++++++++++++++++++++----- arch/x86/kernel/kprobes/core.c | 38 ++++--------------- arch/x86/kernel/static_call.c | 49 ++++++++++++++++++++++-- 4 files changed, 132 insertions(+), 42 deletions(-)
Why is there a v2 series here? Are the ones I just took not correct?
confused,
greg k-h
Because Sasha questioned the presence of the first 2 patches in the series while they were not backported to 6.1. Then, I looked at the 6.1 backport for reference and determined they were not really necessary if I picked the same changes that the 6.1 backport applied.
Thanks. Cascardo.
On Sat, Mar 30, 2024 at 06:57:06AM -0300, Thadeu Lima de Souza Cascardo wrote:
On Fri, Mar 29, 2024 at 01:50:11PM +0100, Greg KH wrote:
On Mon, Mar 18, 2024 at 10:39:04AM -0300, Thadeu Lima de Souza Cascardo wrote:
Otherwise, we see warnings like this:
[ 0.000000][ T0] ------------[ cut here ]------------ [ 0.000000][ T0] unexpected static_call insn opcode 0xf at kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/static_call.c:88 __static_call_validate+0x68/0x70 [ 0.000000][ T0] Modules linked in: [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.151-00083-gf200c7260296 #68 fe3cb25cf78cb710722bb5acd1cadddd35172924 [ 0.000000][ T0] RIP: 0010:__static_call_validate+0x68/0x70 [ 0.000000][ T0] Code: 0f b6 4a 04 81 f1 c0 00 00 00 09 c1 74 cc 80 3d be 2c 02 02 00 75 c3 c6 05 b5 2c 02 02 01 48 c7 c7 38 4f c3 82 e8 e8 c8 09 00 <0f> 0b c3 00 00 cc cc 00 53 48 89 fb 48 63 15 31 71 06 02 e8 b0 b8 [ 0.000000][ T0] RSP: 0000:ffffffff82e03e70 EFLAGS: 00010046 ORIG_RAX: 0000000000000000 [ 0.000000][ T0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 0.000000][ T0] RDX: 0000000000000000 RSI: ffffffff82e03ce0 RDI: 0000000000000001 [ 0.000000][ T0] RBP: 0000000000000001 R08: 00000000ffffffff R09: ffffffff82eaab70 [ 0.000000][ T0] R10: ffffffff82e2e900 R11: 205d305420202020 R12: ffffffff82e51960 [ 0.000000][ T0] R13: ffffffff81038987 R14: ffffffff81038987 R15: 0000000000000001 [ 0.000000][ T0] FS: 0000000000000000(0000) GS:ffffffff83726000(0000) knlGS:0000000000000000 [ 0.000000][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.000000][ T0] CR2: ffff888000014be8 CR3: 00000000037b2000 CR4: 00000000000000a0 [ 0.000000][ T0] Call Trace: [ 0.000000][ T0] <TASK> [ 0.000000][ T0] ? __warn+0x75/0xe0 [ 0.000000][ T0] ? report_bug+0x81/0xe0 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? early_fixup_exception+0x44/0xa0 [ 0.000000][ T0] ? early_idt_handler_common+0x2f/0x40 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? __static_call_validate+0x68/0x70 [ 0.000000][ T0] ? arch_static_call_transform+0x5c/0x90 [ 0.000000][ T0] ? __static_call_init+0x1ec/0x230 [ 0.000000][ T0] ? static_call_init+0x32/0x70 [ 0.000000][ T0] ? setup_arch+0x36/0x4f0 [ 0.000000][ T0] ? start_kernel+0x67/0x400 [ 0.000000][ T0] ? secondary_startup_64_no_verify+0xb1/0xbb [ 0.000000][ T0] </TASK> [ 0.000000][ T0] ---[ end trace 8c8589c01f370686 ]---
Peter Zijlstra (3): x86/alternatives: Introduce int3_emulate_jcc() x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions x86/static_call: Add support for Jcc tail-calls
arch/x86/include/asm/text-patching.h | 31 +++++++++++++++ arch/x86/kernel/alternative.c | 56 +++++++++++++++++++++++----- arch/x86/kernel/kprobes/core.c | 38 ++++--------------- arch/x86/kernel/static_call.c | 49 ++++++++++++++++++++++-- 4 files changed, 132 insertions(+), 42 deletions(-)
Why is there a v2 series here? Are the ones I just took not correct?
confused,
greg k-h
Because Sasha questioned the presence of the first 2 patches in the series while they were not backported to 6.1. Then, I looked at the 6.1 backport for reference and determined they were not really necessary if I picked the same changes that the 6.1 backport applied.
So is what I queued up correct or not?
still confused,
greg k-h
On Sat, Mar 30, 2024 at 11:11:14AM +0100, Greg KH wrote:
On Sat, Mar 30, 2024 at 06:57:06AM -0300, Thadeu Lima de Souza Cascardo wrote:
On Fri, Mar 29, 2024 at 01:50:11PM +0100, Greg KH wrote:
On Mon, Mar 18, 2024 at 10:39:04AM -0300, Thadeu Lima de Souza Cascardo wrote:
Otherwise, we see warnings like this:
[ 0.000000][ T0] ------------[ cut here ]------------ [ 0.000000][ T0] unexpected static_call insn opcode 0xf at kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/static_call.c:88 __static_call_validate+0x68/0x70 [ 0.000000][ T0] Modules linked in: [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.151-00083-gf200c7260296 #68 fe3cb25cf78cb710722bb5acd1cadddd35172924 [ 0.000000][ T0] RIP: 0010:__static_call_validate+0x68/0x70 [ 0.000000][ T0] Code: 0f b6 4a 04 81 f1 c0 00 00 00 09 c1 74 cc 80 3d be 2c 02 02 00 75 c3 c6 05 b5 2c 02 02 01 48 c7 c7 38 4f c3 82 e8 e8 c8 09 00 <0f> 0b c3 00 00 cc cc 00 53 48 89 fb 48 63 15 31 71 06 02 e8 b0 b8 [ 0.000000][ T0] RSP: 0000:ffffffff82e03e70 EFLAGS: 00010046 ORIG_RAX: 0000000000000000 [ 0.000000][ T0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 0.000000][ T0] RDX: 0000000000000000 RSI: ffffffff82e03ce0 RDI: 0000000000000001 [ 0.000000][ T0] RBP: 0000000000000001 R08: 00000000ffffffff R09: ffffffff82eaab70 [ 0.000000][ T0] R10: ffffffff82e2e900 R11: 205d305420202020 R12: ffffffff82e51960 [ 0.000000][ T0] R13: ffffffff81038987 R14: ffffffff81038987 R15: 0000000000000001 [ 0.000000][ T0] FS: 0000000000000000(0000) GS:ffffffff83726000(0000) knlGS:0000000000000000 [ 0.000000][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.000000][ T0] CR2: ffff888000014be8 CR3: 00000000037b2000 CR4: 00000000000000a0 [ 0.000000][ T0] Call Trace: [ 0.000000][ T0] <TASK> [ 0.000000][ T0] ? __warn+0x75/0xe0 [ 0.000000][ T0] ? report_bug+0x81/0xe0 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? early_fixup_exception+0x44/0xa0 [ 0.000000][ T0] ? early_idt_handler_common+0x2f/0x40 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? kvm_vcpu_reload_apic_access_page+0x17/0x30 [ 0.000000][ T0] ? __static_call_validate+0x68/0x70 [ 0.000000][ T0] ? arch_static_call_transform+0x5c/0x90 [ 0.000000][ T0] ? __static_call_init+0x1ec/0x230 [ 0.000000][ T0] ? static_call_init+0x32/0x70 [ 0.000000][ T0] ? setup_arch+0x36/0x4f0 [ 0.000000][ T0] ? start_kernel+0x67/0x400 [ 0.000000][ T0] ? secondary_startup_64_no_verify+0xb1/0xbb [ 0.000000][ T0] </TASK> [ 0.000000][ T0] ---[ end trace 8c8589c01f370686 ]---
Peter Zijlstra (3): x86/alternatives: Introduce int3_emulate_jcc() x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions x86/static_call: Add support for Jcc tail-calls
arch/x86/include/asm/text-patching.h | 31 +++++++++++++++ arch/x86/kernel/alternative.c | 56 +++++++++++++++++++++++----- arch/x86/kernel/kprobes/core.c | 38 ++++--------------- arch/x86/kernel/static_call.c | 49 ++++++++++++++++++++++-- 4 files changed, 132 insertions(+), 42 deletions(-)
Why is there a v2 series here? Are the ones I just took not correct?
confused,
greg k-h
Because Sasha questioned the presence of the first 2 patches in the series while they were not backported to 6.1. Then, I looked at the 6.1 backport for reference and determined they were not really necessary if I picked the same changes that the 6.1 backport applied.
So is what I queued up correct or not?
still confused,
greg k-h
Either version are good. I understand there is a preference for v2 since it doesn't include a change that was not applied in a later series, 6.1.y.
Cascardo.
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Thadeu Lima de Souza Cascardo