github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-01 02:53:36 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

x86/alternatives: Introduce 'struct smp_text_poke_array' and move tp_vec and tp_vec_nr to it

Browse Source 
struct text_poke_array is an equivalent structure to these global variables:

	static struct smp_text_poke_loc tp_vec[TP_VEC_MAX];
	static int tp_vec_nr;

Note that we intentionally mirror much of the naming of
'struct text_poke_int3_vec', which will further highlight
the unecessary layering going on in this code, and will
ease its removal.

No change in functionality.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-28-mingo@kernel.org
This commit is contained in:
Ingo Molnar 2025-04-11 07:40:39 +02:00
parent 37725b64a9
commit 6e7dc03aee
1 changed files with 23 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
arch/x86/kernel/alternative.c
View File

@ -2467,14 +2467,21 @@ struct smp_text_poke_loc {
};
struct text_poke_int3_vec {
struct smp_text_poke_loc *vec;
int nr_entries;
struct smp_text_poke_loc *vec;
};
static DEFINE_PER_CPU(atomic_t, text_poke_array_refs);
static struct text_poke_int3_vec int3_vec;
#define TP_ARRAY_NR_ENTRIES_MAX (PAGE_SIZE / sizeof(struct smp_text_poke_loc))
static struct smp_text_poke_array {
int nr_entries;
struct smp_text_poke_loc vec[TP_ARRAY_NR_ENTRIES_MAX];
} text_poke_array;
static __always_inline
struct text_poke_int3_vec *try_get_desc(void)
{
@ -2510,10 +2517,6 @@ static __always_inline int patch_cmp(const void *key, const void *elt)
return 0;
}
#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct smp_text_poke_loc))
static struct smp_text_poke_loc tp_vec[TP_VEC_MAX];
static int tp_vec_nr;
noinstr int smp_text_poke_int3_handler(struct pt_regs *regs)
{
struct text_poke_int3_vec *desc;
@ -2538,7 +2541,7 @@ noinstr int smp_text_poke_int3_handler(struct pt_regs *regs)
if (!desc)
return 0;
WARN_ON_ONCE(desc->vec != tp_vec);
WARN_ON_ONCE(desc->vec != text_poke_array.vec);
/*
* Discount the INT3. See smp_text_poke_batch_process().
@ -2627,8 +2630,8 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
lockdep_assert_held(&text_mutex);
WARN_ON_ONCE(tp != tp_vec);
WARN_ON_ONCE(nr_entries != tp_vec_nr);
WARN_ON_ONCE(tp != text_poke_array.vec);
WARN_ON_ONCE(nr_entries != text_poke_array.nr_entries);
int3_vec.vec = tp;
int3_vec.nr_entries = nr_entries;
@ -2843,7 +2846,7 @@ static void text_poke_int3_loc_init(struct smp_text_poke_loc *tp, void *addr,
}
/*
* We hard rely on the tp_vec being ordered; ensure this is so by flushing
* We hard rely on the text_poke_array.vec being ordered; ensure this is so by flushing
* early if needed.
*/
static bool text_poke_addr_ordered(void *addr)
@ -2852,7 +2855,7 @@ static bool text_poke_addr_ordered(void *addr)
WARN_ON_ONCE(!addr);
if (!tp_vec_nr)
if (!text_poke_array.nr_entries)
return true;
/*
@ -2861,7 +2864,7 @@ static bool text_poke_addr_ordered(void *addr)
* is violated and we must first flush all pending patching
* requests:
*/
tp = &tp_vec[tp_vec_nr-1];
tp = &text_poke_array.vec[text_poke_array.nr_entries-1];
if ((unsigned long)text_poke_addr(tp) > (unsigned long)addr)
return false;
@ -2870,9 +2873,9 @@ static bool text_poke_addr_ordered(void *addr)
void smp_text_poke_batch_finish(void)
{
if (tp_vec_nr) {
smp_text_poke_batch_process(tp_vec, tp_vec_nr);
tp_vec_nr = 0;
if (text_poke_array.nr_entries) {
smp_text_poke_batch_process(text_poke_array.vec, text_poke_array.nr_entries);
text_poke_array.nr_entries = 0;
}
}
@ -2880,9 +2883,9 @@ static void smp_text_poke_batch_flush(void *addr)
{
lockdep_assert_held(&text_mutex);
if (tp_vec_nr == TP_VEC_MAX || !text_poke_addr_ordered(addr)) {
smp_text_poke_batch_process(tp_vec, tp_vec_nr);
tp_vec_nr = 0;
if (text_poke_array.nr_entries == TP_ARRAY_NR_ENTRIES_MAX || !text_poke_addr_ordered(addr)) {
smp_text_poke_batch_process(text_poke_array.vec, text_poke_array.nr_entries);
text_poke_array.nr_entries = 0;
}
}
@ -2892,7 +2895,7 @@ void __ref smp_text_poke_batch_add(void *addr, const void *opcode, size_t len, c
smp_text_poke_batch_flush(addr);
tp = &tp_vec[tp_vec_nr++];
tp = &text_poke_array.vec[text_poke_array.nr_entries++];
text_poke_int3_loc_init(tp, addr, opcode, len, emulate);
}
@ -2912,9 +2915,9 @@ void __ref smp_text_poke_single(void *addr, const void *opcode, size_t len, cons
struct smp_text_poke_loc *tp;
/* Batch-patching should not be mixed with single-patching: */
WARN_ON_ONCE(tp_vec_nr != 0);
WARN_ON_ONCE(text_poke_array.nr_entries != 0);
tp = &tp_vec[tp_vec_nr++];
tp = &text_poke_array.vec[text_poke_array.nr_entries++];
text_poke_int3_loc_init(tp, addr, opcode, len, emulate);
smp_text_poke_batch_finish();