From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
mhiramat@kernel.org, kirill.shutemov@linux.intel.com,
Andrew.Cooper3@citrix.com, jpoimboe@redhat.com
Subject: [PATCH v3 1/4] x86/alternative: Make debug-alternative selective
Date: Wed, 08 Feb 2023 18:10:51 +0100 [thread overview]
Message-ID: <20230208171431.253636689@infradead.org> (raw)
In-Reply-To: 20230208171050.490809180@infradead.org
Using debug-alternative generates a *LOT* of output, extend it a bit
to select which of the many rewrites it reports on.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/alternative.c | 62 +++++++++++++++++++++++++-----------------
1 file changed, 37 insertions(+), 25 deletions(-)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -37,11 +37,23 @@ EXPORT_SYMBOL_GPL(alternatives_patched);
#define MAX_PATCH_LEN (255-1)
-static int __initdata_or_module debug_alternative;
+#define DA_ALL (~0)
+#define DA_ALT 0x01
+#define DA_RET 0x02
+#define DA_RETPOLINE 0x04
+#define DA_ENDBR 0x08
+#define DA_SMP 0x10
+
+static unsigned int __initdata_or_module debug_alternative;
static int __init debug_alt(char *str)
{
- debug_alternative = 1;
+ if (str && *str == '=')
+ str++;
+
+ if (!str || kstrtouint(str, 0, &debug_alternative))
+ debug_alternative = DA_ALL;
+
return 1;
}
__setup("debug-alternative", debug_alt);
@@ -55,15 +67,15 @@ static int __init setup_noreplace_smp(ch
}
__setup("noreplace-smp", setup_noreplace_smp);
-#define DPRINTK(fmt, args...) \
+#define DPRINTK(type, fmt, args...) \
do { \
- if (debug_alternative) \
+ if (debug_alternative & DA_##type) \
printk(KERN_DEBUG pr_fmt(fmt) "\n", ##args); \
} while (0)
-#define DUMP_BYTES(buf, len, fmt, args...) \
+#define DUMP_BYTES(type, buf, len, fmt, args...) \
do { \
- if (unlikely(debug_alternative)) { \
+ if (unlikely(debug_alternative & DA_##type)) { \
int j; \
\
if (!(len)) \
@@ -148,7 +160,7 @@ recompute_jump(struct alt_instr *a, u8 *
tgt_rip = next_rip + o_dspl;
n_dspl = tgt_rip - orig_insn;
- DPRINTK("target RIP: %px, new_displ: 0x%x", tgt_rip, n_dspl);
+ DPRINTK(ALT, "target RIP: %px, new_displ: 0x%x", tgt_rip, n_dspl);
if (tgt_rip - orig_insn >= 0) {
if (n_dspl - 2 <= 127)
@@ -183,7 +195,7 @@ recompute_jump(struct alt_instr *a, u8 *
done:
- DPRINTK("final displ: 0x%08x, JMP 0x%lx",
+ DPRINTK(ALT, "final displ: 0x%08x, JMP 0x%lx",
n_dspl, (unsigned long)orig_insn + n_dspl + repl_len);
}
@@ -217,7 +229,7 @@ static __always_inline int optimize_nops
add_nops(instr + off, nnops);
local_irq_restore(flags);
- DUMP_BYTES(instr, instrlen, "%px: [%d:%d) optimized NOPs: ", instr, off, i);
+ DUMP_BYTES(ALT, instr, instrlen, "%px: [%d:%d) optimized NOPs: ", instr, off, i);
return nnops;
}
@@ -270,7 +282,7 @@ void __init_or_module noinline apply_alt
u8 *instr, *replacement;
u8 insn_buff[MAX_PATCH_LEN];
- DPRINTK("alt table %px, -> %px", start, end);
+ DPRINTK(ALT, "alt table %px, -> %px", start, end);
/*
* The scan order should be from start to end. A later scanned
* alternative code can overwrite previously scanned alternative code.
@@ -299,15 +311,15 @@ void __init_or_module noinline apply_alt
if (!boot_cpu_has(feature) == !(a->cpuid & ALTINSTR_FLAG_INV))
goto next;
- DPRINTK("feat: %s%d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d)",
+ DPRINTK(ALT, "feat: %s%d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d)",
(a->cpuid & ALTINSTR_FLAG_INV) ? "!" : "",
feature >> 5,
feature & 0x1f,
instr, instr, a->instrlen,
replacement, a->replacementlen);
- DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr);
- DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement);
+ DUMP_BYTES(ALT, instr, a->instrlen, "%px: old_insn: ", instr);
+ DUMP_BYTES(ALT, replacement, a->replacementlen, "%px: rpl_insn: ", replacement);
memcpy(insn_buff, replacement, a->replacementlen);
insn_buff_sz = a->replacementlen;
@@ -320,7 +332,7 @@ void __init_or_module noinline apply_alt
*/
if (a->replacementlen == 5 && *insn_buff == 0xe8) {
*(s32 *)(insn_buff + 1) += replacement - instr;
- DPRINTK("Fix CALL offset: 0x%x, CALL 0x%lx",
+ DPRINTK(ALT, "Fix CALL offset: 0x%x, CALL 0x%lx",
*(s32 *)(insn_buff + 1),
(unsigned long)instr + *(s32 *)(insn_buff + 1) + 5);
}
@@ -331,7 +343,7 @@ void __init_or_module noinline apply_alt
for (; insn_buff_sz < a->instrlen; insn_buff_sz++)
insn_buff[insn_buff_sz] = 0x90;
- DUMP_BYTES(insn_buff, insn_buff_sz, "%px: final_insn: ", instr);
+ DUMP_BYTES(ALT, insn_buff, insn_buff_sz, "%px: final_insn: ", instr);
text_poke_early(instr, insn_buff, insn_buff_sz);
@@ -557,15 +569,15 @@ void __init_or_module noinline apply_ret
continue;
}
- DPRINTK("retpoline at: %pS (%px) len: %d to: %pS",
+ DPRINTK(RETPOLINE, "retpoline at: %pS (%px) len: %d to: %pS",
addr, addr, insn.length,
addr + insn.length + insn.immediate.value);
len = patch_retpoline(addr, &insn, bytes);
if (len == insn.length) {
optimize_nops(bytes, len);
- DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr);
- DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
+ DUMP_BYTES(RETPOLINE, ((u8*)addr), len, "%px: orig: ", addr);
+ DUMP_BYTES(RETPOLINE, ((u8*)bytes), len, "%px: repl: ", addr);
text_poke_early(addr, bytes, len);
}
}
@@ -632,14 +644,14 @@ void __init_or_module noinline apply_ret
addr, dest, 5, addr))
continue;
- DPRINTK("return thunk at: %pS (%px) len: %d to: %pS",
+ DPRINTK(RET, "return thunk at: %pS (%px) len: %d to: %pS",
addr, addr, insn.length,
addr + insn.length + insn.immediate.value);
len = patch_return(addr, &insn, bytes);
if (len == insn.length) {
- DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr);
- DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
+ DUMP_BYTES(RET, ((u8*)addr), len, "%px: orig: ", addr);
+ DUMP_BYTES(RET, ((u8*)bytes), len, "%px: repl: ", addr);
text_poke_early(addr, bytes, len);
}
}
@@ -669,13 +681,13 @@ static void poison_endbr(void *addr, boo
return;
}
- DPRINTK("ENDBR at: %pS (%px)", addr, addr);
+ DPRINTK(ENDBR, "ENDBR at: %pS (%px)", addr, addr);
/*
* When we have IBT, the lack of ENDBR will trigger #CP
*/
- DUMP_BYTES(((u8*)addr), 4, "%px: orig: ", addr);
- DUMP_BYTES(((u8*)&poison), 4, "%px: repl: ", addr);
+ DUMP_BYTES(ENDBR, ((u8*)addr), 4, "%px: orig: ", addr);
+ DUMP_BYTES(ENDBR, ((u8*)&poison), 4, "%px: repl: ", addr);
text_poke_early(addr, &poison, 4);
}
@@ -1150,7 +1162,7 @@ void __init_or_module alternatives_smp_m
smp->locks_end = locks_end;
smp->text = text;
smp->text_end = text_end;
- DPRINTK("locks %p -> %p, text %p -> %p, name %s\n",
+ DPRINTK(SMP, "locks %p -> %p, text %p -> %p, name %s\n",
smp->locks, smp->locks_end,
smp->text, smp->text_end, smp->name);
next prev parent reply other threads:[~2023-02-08 17:18 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-08 17:10 [PATCH v3 0/4] x86: Fully relocatable alternatives and some NOPs Peter Zijlstra
2023-02-08 17:10 ` Peter Zijlstra [this message]
2023-02-14 11:48 ` [PATCH v3 1/4] x86/alternative: Make debug-alternative selective Borislav Petkov
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-02-08 17:10 ` [PATCH v3 2/4] x86/alternative: Support relocations in alternatives Peter Zijlstra
2023-02-17 20:28 ` Borislav Petkov
2023-02-17 22:21 ` Borislav Petkov
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-02-08 17:10 ` [PATCH v3 3/4] x86/alternative: Rewrite optimize_nops() some Peter Zijlstra
2023-02-08 19:52 ` Andrew.Cooper3
2023-02-08 20:29 ` Peter Zijlstra
2023-02-08 20:36 ` Peter Zijlstra
2023-02-08 20:44 ` Peter Zijlstra
2023-02-08 20:45 ` Peter Zijlstra
2023-02-08 21:01 ` Peter Zijlstra
2023-02-08 21:08 ` Peter Zijlstra
2023-02-08 21:21 ` Peter Zijlstra
2023-02-09 1:11 ` Andrew.Cooper3
2023-02-09 22:27 ` David Laight
2023-02-09 1:33 ` Andrew.Cooper3
2023-02-08 23:04 ` David Laight
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-02-08 17:10 ` [PATCH v3 4/4] x86/alternative: Complicate optimize_nops() some more Peter Zijlstra
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-05-13 16:01 ` [PATCH] x86/alternatives: Fix section mismatch warnings Borislav Petkov
2023-05-13 16:10 ` [tip: x86/alternatives] " tip-bot2 for Borislav Petkov (AMD)
2023-02-27 10:49 ` [PATCH] x86/lib/memmove: Decouple ERMS from FSRM Borislav Petkov
2023-04-27 9:22 ` [PATCH TEST] " Yahu Gao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230208171431.253636689@infradead.org \
--to=peterz@infradead.org \
--cc=Andrew.Cooper3@citrix.com \
--cc=jpoimboe@redhat.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.