2024-03-27 16:11:28

by Samuel Holland

Subject: [PATCH v2 0/7] riscv: Various text patching improvements

Here are a few changes to minimize calls to stop_machine() and
flush_icache_*() in the various text patching functions, as well as
to simplify the code.

This series is based on "[PATCH v3 0/2] riscv: fix patching with IPI"[1].

[1]: https://lore.kernel.org/linux-riscv/[email protected]/

Changes in v2:
- Remove unnecessary line wrapping
- Further simplify patch_insn_set()/patch_insn_write() loop conditions
- Use min() instead of min_t() since both sides are unsigned long

Samuel Holland (7):
riscv: jump_label: Batch icache maintenance
riscv: jump_label: Simplify assembly syntax
riscv: kprobes: Use patch_text_nosync() for insn slots
riscv: Simplify text patching loops
riscv: Pass patch_text() the length in bytes
riscv: Use offset_in_page() in text patching functions
riscv: Remove extra variable in patch_text_nosync()

arch/riscv/include/asm/jump_label.h | 4 +-
arch/riscv/include/asm/patch.h | 2 +-
arch/riscv/kernel/jump_label.c | 16 +++++--
arch/riscv/kernel/patch.c | 69 ++++++++++++++---------------
arch/riscv/kernel/probes/kprobes.c | 19 ++++----
arch/riscv/net/bpf_jit_comp64.c | 7 +--
6 files changed, 63 insertions(+), 54 deletions(-)

--
2.43.1

2024-03-27 16:11:41

by Samuel Holland

Subject: [PATCH v2 1/7] riscv: jump_label: Batch icache maintenance

Switch to the batched version of the jump label update functions so
instruction cache maintenance is deferred until the end of the update.

Reviewed-by: Björn Töpel <[email protected]>
Signed-off-by: Samuel Holland <[email protected]>
---

(no changes since v1)

arch/riscv/include/asm/jump_label.h | 2 ++
arch/riscv/kernel/jump_label.c | 16 ++++++++++++----
2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h
index 4a35d787c019..6290b26f4a14 100644
--- a/arch/riscv/include/asm/jump_label.h
+++ b/arch/riscv/include/asm/jump_label.h
@@ -12,6 +12,8 @@
#include <linux/types.h>
#include <asm/asm.h>

+#define HAVE_JUMP_LABEL_BATCH
+
#define JUMP_LABEL_NOP_SIZE 4

static __always_inline bool arch_static_branch(struct static_key * const key,
diff --git a/arch/riscv/kernel/jump_label.c b/arch/riscv/kernel/jump_label.c
index e6694759dbd0..11ad789c60c6 100644
--- a/arch/riscv/kernel/jump_label.c
+++ b/arch/riscv/kernel/jump_label.c
@@ -9,13 +9,14 @@
#include <linux/memory.h>
#include <linux/mutex.h>
#include <asm/bug.h>
+#include <asm/cacheflush.h>
#include <asm/patch.h>

#define RISCV_INSN_NOP 0x00000013U
#define RISCV_INSN_JAL 0x0000006fU

-void arch_jump_label_transform(struct jump_entry *entry,
- enum jump_label_type type)
+bool arch_jump_label_transform_queue(struct jump_entry *entry,
+ enum jump_label_type type)
{
void *addr = (void *)jump_entry_code(entry);
u32 insn;
@@ -24,7 +25,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
long offset = jump_entry_target(entry) - jump_entry_code(entry);

if (WARN_ON(offset & 1 || offset < -524288 || offset >= 524288))
- return;
+ return true;

insn = RISCV_INSN_JAL |
(((u32)offset & GENMASK(19, 12)) << (12 - 12)) |
@@ -36,6 +37,13 @@ void arch_jump_label_transform(struct jump_entry *entry,
}

mutex_lock(&text_mutex);
- patch_text_nosync(addr, &insn, sizeof(insn));
+ patch_insn_write(addr, &insn, sizeof(insn));
mutex_unlock(&text_mutex);
+
+ return true;
+}
+
+void arch_jump_label_transform_apply(void)
+{
+ flush_icache_all();
}
--
2.43.1

2024-03-27 16:11:57

by Samuel Holland

Subject: [PATCH v2 2/7] riscv: jump_label: Simplify assembly syntax

The idiomatic way to write "jal zero" is "j".

Reviewed-by: Björn Töpel <[email protected]>
Signed-off-by: Samuel Holland <[email protected]>
---

(no changes since v1)

arch/riscv/include/asm/jump_label.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h
index 6290b26f4a14..1c768d02bd0c 100644
--- a/arch/riscv/include/asm/jump_label.h
+++ b/arch/riscv/include/asm/jump_label.h
@@ -46,7 +46,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke
" .option push \n\t"
" .option norelax \n\t"
" .option norvc \n\t"
- "1: jal zero, %l[label] \n\t"
+ "1: j %l[label] \n\t"
" .option pop \n\t"
" .pushsection __jump_table, \"aw\" \n\t"
" .align " RISCV_LGPTR " \n\t"
--
2.43.1

2024-03-27 16:12:06

by Samuel Holland

Subject: [PATCH v2 3/7] riscv: kprobes: Use patch_text_nosync() for insn slots

These instructions are not yet visible to the rest of the system,
so there is no need to do the whole stop_machine() dance.

Reviewed-by: Björn Töpel <[email protected]>
Signed-off-by: Samuel Holland <[email protected]>
---

Changes in v2:
- Remove unnecessary line wrapping

arch/riscv/kernel/probes/kprobes.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index 2f08c14a933d..fecbbcf40ac3 100644
--- a/arch/riscv/kernel/probes/kprobes.c
+++ b/arch/riscv/kernel/probes/kprobes.c
@@ -28,9 +28,8 @@ static void __kprobes arch_prepare_ss_slot(struct kprobe *p)

p->ainsn.api.restore = (unsigned long)p->addr + offset;

- patch_text(p->ainsn.api.insn, &p->opcode, 1);
- patch_text((void *)((unsigned long)(p->ainsn.api.insn) + offset),
- &insn, 1);
+ patch_text_nosync(p->ainsn.api.insn, &p->opcode, 1);
+ patch_text_nosync(p->ainsn.api.insn + offset, &insn, 1);
}

static void __kprobes arch_prepare_simulate(struct kprobe *p)
--
2.43.1

2024-03-27 16:12:13

by Samuel Holland

Subject: [PATCH v2 4/7] riscv: Simplify text patching loops

This reduces the number of variables and makes the code easier to parse.

Signed-off-by: Samuel Holland <[email protected]>
---

Changes in v2:
- Further simplify patch_insn_set()/patch_insn_write() loop conditions
- Use min() instead of min_t() since both sides are unsigned long

arch/riscv/kernel/patch.c | 37 +++++++++++++++++++++----------------
1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index 9a1bce1adf5a..0d1700d1934c 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -155,22 +155,24 @@ NOKPROBE_SYMBOL(__patch_insn_write);

static int patch_insn_set(void *addr, u8 c, size_t len)
{
- size_t patched = 0;
size_t size;
- int ret = 0;
+ int ret;

/*
* __patch_insn_set() can only work on 2 pages at a time so call it in a
* loop with len <= 2 * PAGE_SIZE.
*/
- while (patched < len && !ret) {
- size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched);
- ret = __patch_insn_set(addr + patched, c, size);
-
- patched += size;
+ while (len) {
+ size = min(len, PAGE_SIZE * 2 - offset_in_page(addr));
+ ret = __patch_insn_set(addr, c, size);
+ if (ret)
+ return ret;
+
+ addr += size;
+ len -= size;
}

- return ret;
+ return 0;
}
NOKPROBE_SYMBOL(patch_insn_set);

@@ -190,22 +192,25 @@ NOKPROBE_SYMBOL(patch_text_set_nosync);

int patch_insn_write(void *addr, const void *insn, size_t len)
{
- size_t patched = 0;
size_t size;
- int ret = 0;
+ int ret;

/*
* Copy the instructions to the destination address, two pages at a time
* because __patch_insn_write() can only handle len <= 2 * PAGE_SIZE.
*/
- while (patched < len && !ret) {
- size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched);
- ret = __patch_insn_write(addr + patched, insn + patched, size);
-
- patched += size;
+ while (len) {
+ size = min(len, PAGE_SIZE * 2 - offset_in_page(addr));
+ ret = __patch_insn_write(addr, insn, size);
+ if (ret)
+ return ret;
+
+ addr += size;
+ insn += size;
+ len -= size;
}

- return ret;
+ return 0;
}
NOKPROBE_SYMBOL(patch_insn_write);

--
2.43.1

2024-03-27 16:12:36

by Samuel Holland

Subject: [PATCH v2 5/7] riscv: Pass patch_text() the length in bytes

patch_text_nosync() already handles an arbitrary length of code, so this
removes a superfluous loop and reduces the number of icache flushes.

Reviewed-by: Björn Töpel <[email protected]>
Signed-off-by: Samuel Holland <[email protected]>
---

Changes in v2:
- Remove unnecessary line wrapping

arch/riscv/include/asm/patch.h | 2 +-
arch/riscv/kernel/patch.c | 14 +++++---------
arch/riscv/kernel/probes/kprobes.c | 18 ++++++++++--------
arch/riscv/net/bpf_jit_comp64.c | 7 ++++---
4 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h
index 9f5d6e14c405..7228e266b9a1 100644
--- a/arch/riscv/include/asm/patch.h
+++ b/arch/riscv/include/asm/patch.h
@@ -9,7 +9,7 @@
int patch_insn_write(void *addr, const void *insn, size_t len);
int patch_text_nosync(void *addr, const void *insns, size_t len);
int patch_text_set_nosync(void *addr, u8 c, size_t len);
-int patch_text(void *addr, u32 *insns, int ninsns);
+int patch_text(void *addr, u32 *insns, size_t len);

extern int riscv_patch_in_stop_machine;

diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index 0d1700d1934c..243e1573410b 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -19,7 +19,7 @@
struct patch_insn {
void *addr;
u32 *insns;
- int ninsns;
+ size_t len;
atomic_t cpu_count;
};

@@ -231,14 +231,10 @@ NOKPROBE_SYMBOL(patch_text_nosync);
static int patch_text_cb(void *data)
{
struct patch_insn *patch = data;
- unsigned long len;
- int i, ret = 0;
+ int ret = 0;

if (atomic_inc_return(&patch->cpu_count) == num_online_cpus()) {
- for (i = 0; ret == 0 && i < patch->ninsns; i++) {
- len = GET_INSN_LENGTH(patch->insns[i]);
- ret = patch_insn_write(patch->addr + i * len, &patch->insns[i], len);
- }
+ ret = patch_insn_write(patch->addr, patch->insns, patch->len);
/*
* Make sure the patching store is effective *before* we
* increment the counter which releases all waiting CPUs
@@ -258,13 +254,13 @@ static int patch_text_cb(void *data)
}
NOKPROBE_SYMBOL(patch_text_cb);

-int patch_text(void *addr, u32 *insns, int ninsns)
+int patch_text(void *addr, u32 *insns, size_t len)
{
int ret;
struct patch_insn patch = {
.addr = addr,
.insns = insns,
- .ninsns = ninsns,
+ .len = len,
.cpu_count = ATOMIC_INIT(0),
};

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index fecbbcf40ac3..f3cbc3ec9e6a 100644
--- a/arch/riscv/kernel/probes/kprobes.c
+++ b/arch/riscv/kernel/probes/kprobes.c
@@ -23,13 +23,13 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);

static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
{
+ size_t len = GET_INSN_LENGTH(p->opcode);
u32 insn = __BUG_INSN_32;
- unsigned long offset = GET_INSN_LENGTH(p->opcode);

- p->ainsn.api.restore = (unsigned long)p->addr + offset;
+ p->ainsn.api.restore = (unsigned long)p->addr + len;

- patch_text_nosync(p->ainsn.api.insn, &p->opcode, 1);
- patch_text_nosync(p->ainsn.api.insn + offset, &insn, 1);
+ patch_text_nosync(p->ainsn.api.insn, &p->opcode, len);
+ patch_text_nosync(p->ainsn.api.insn + len, &insn, GET_INSN_LENGTH(insn));
}

static void __kprobes arch_prepare_simulate(struct kprobe *p)
@@ -116,16 +116,18 @@ void *alloc_insn_page(void)
/* install breakpoint in text */
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
- u32 insn = (p->opcode & __INSN_LENGTH_MASK) == __INSN_LENGTH_32 ?
- __BUG_INSN_32 : __BUG_INSN_16;
+ size_t len = GET_INSN_LENGTH(p->opcode);
+ u32 insn = len == 4 ? __BUG_INSN_32 : __BUG_INSN_16;

- patch_text(p->addr, &insn, 1);
+ patch_text(p->addr, &insn, len);
}

/* remove breakpoint from text */
void __kprobes arch_disarm_kprobe(struct kprobe *p)
{
- patch_text(p->addr, &p->opcode, 1);
+ size_t len = GET_INSN_LENGTH(p->opcode);
+
+ patch_text(p->addr, &p->opcode, len);
}

void __kprobes arch_remove_kprobe(struct kprobe *p)
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index aac190085472..6ed4035a8136 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -15,6 +15,7 @@
#include "bpf_jit.h"

#define RV_FENTRY_NINSNS 2
+#define RV_FENTRY_NBYTES (RV_FENTRY_NINSNS * 4)

#define RV_REG_TCC RV_REG_A6
#define RV_REG_TCC_SAVED RV_REG_S6 /* Store A6 in S6 if program do calls */
@@ -663,7 +664,7 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type,
if (ret)
return ret;

- if (memcmp(ip, old_insns, RV_FENTRY_NINSNS * 4))
+ if (memcmp(ip, old_insns, RV_FENTRY_NBYTES))
return -EFAULT;

ret = gen_jump_or_nops(new_addr, ip, new_insns, is_call);
@@ -672,8 +673,8 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type,

cpus_read_lock();
mutex_lock(&text_mutex);
- if (memcmp(ip, new_insns, RV_FENTRY_NINSNS * 4))
- ret = patch_text(ip, new_insns, RV_FENTRY_NINSNS);
+ if (memcmp(ip, new_insns, RV_FENTRY_NBYTES))
+ ret = patch_text(ip, new_insns, RV_FENTRY_NBYTES);
mutex_unlock(&text_mutex);
cpus_read_unlock();

--
2.43.1

2024-03-27 16:12:57

by Samuel Holland

Subject: [PATCH v2 7/7] riscv: Remove extra variable in patch_text_nosync()

This cast is superfluous, and is incorrect anyway if compressed
instructions may be present.

Reviewed-by: Björn Töpel <[email protected]>
Signed-off-by: Samuel Holland <[email protected]>
---

(no changes since v1)

arch/riscv/kernel/patch.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index cfcb9926e722..9b8d633f6536 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -178,13 +178,11 @@ NOKPROBE_SYMBOL(patch_insn_set);

int patch_text_set_nosync(void *addr, u8 c, size_t len)
{
- u32 *tp = addr;
int ret;

- ret = patch_insn_set(tp, c, len);
-
+ ret = patch_insn_set(addr, c, len);
if (!ret)
- flush_icache_range((uintptr_t)tp, (uintptr_t)tp + len);
+ flush_icache_range((uintptr_t)addr, (uintptr_t)addr + len);

return ret;
}
@@ -216,13 +214,11 @@ NOKPROBE_SYMBOL(patch_insn_write);

int patch_text_nosync(void *addr, const void *insns, size_t len)
{
- u32 *tp = addr;
int ret;

- ret = patch_insn_write(tp, insns, len);
-
+ ret = patch_insn_write(addr, insns, len);
if (!ret)
- flush_icache_range((uintptr_t) tp, (uintptr_t) tp + len);
+ flush_icache_range((uintptr_t)addr, (uintptr_t)addr + len);

return ret;
}
--
2.43.1

2024-03-27 16:35:26

by Samuel Holland

Subject: [PATCH v2 6/7] riscv: Use offset_in_page() in text patching functions

This is a bit easier to parse than the equivalent bit manipulation.

Reviewed-by: Björn Töpel <[email protected]>
Signed-off-by: Samuel Holland <[email protected]>
---

(no changes since v1)

arch/riscv/kernel/patch.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index 243e1573410b..cfcb9926e722 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -54,7 +54,7 @@ static __always_inline void *patch_map(void *addr, const unsigned int fixmap)
BUG_ON(!page);

return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
- (uintaddr & ~PAGE_MASK));
+ offset_in_page(addr));
}

static void patch_unmap(int fixmap)
@@ -65,8 +65,8 @@ NOKPROBE_SYMBOL(patch_unmap);

static int __patch_insn_set(void *addr, u8 c, size_t len)
{
+ bool across_pages = (offset_in_page(addr) + len) > PAGE_SIZE;
void *waddr = addr;
- bool across_pages = (((uintptr_t)addr & ~PAGE_MASK) + len) > PAGE_SIZE;

/*
* Only two pages can be mapped at a time for writing.
@@ -98,8 +98,8 @@ NOKPROBE_SYMBOL(__patch_insn_set);

static int __patch_insn_write(void *addr, const void *insn, size_t len)
{
+ bool across_pages = (offset_in_page(addr) + len) > PAGE_SIZE;
void *waddr = addr;
- bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE;
int ret;

/*
--
2.43.1

2024-04-02 11:14:10

by Björn Töpel

Subject: Re: [PATCH v2 4/7] riscv: Simplify text patching loops

Samuel Holland <[email protected]> writes:

> This reduces the number of variables and makes the code easier to parse.
>
> Signed-off-by: Samuel Holland <[email protected]>
> ---
>
> Changes in v2:
> - Further simplify patch_insn_set()/patch_insn_write() loop conditions
> - Use min() instead of min_t() since both sides are unsigned long

Thanks for addressing the changes! Nice cleanup!

Reviewed-by: Björn Töpel <[email protected]>

2024-04-24 10:44:27

by Conor Dooley

Subject: Re: [PATCH v2 4/7] riscv: Simplify text patching loops

On Wed, Mar 27, 2024 at 09:04:43AM -0700, Samuel Holland wrote:
> This reduces the number of variables and makes the code easier to parse.
>
> Signed-off-by: Samuel Holland <[email protected]>
> ---
>
> Changes in v2:
> - Further simplify patch_insn_set()/patch_insn_write() loop conditions
> - Use min() instead of min_t() since both sides are unsigned long
>
> arch/riscv/kernel/patch.c | 37 +++++++++++++++++++++----------------
> 1 file changed, 21 insertions(+), 16 deletions(-)
>
> diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
> index 9a1bce1adf5a..0d1700d1934c 100644
> --- a/arch/riscv/kernel/patch.c
> +++ b/arch/riscv/kernel/patch.c
> @@ -155,22 +155,24 @@ NOKPROBE_SYMBOL(__patch_insn_write);
>
> static int patch_insn_set(void *addr, u8 c, size_t len)
> {
> - size_t patched = 0;
> size_t size;
> - int ret = 0;
>
> /*
> * __patch_insn_set() can only work on 2 pages at a time so call it in a
> * loop with len <= 2 * PAGE_SIZE.
> */
> - while (patched < len && !ret) {
> - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched);
> - ret = __patch_insn_set(addr + patched, c, size);
> -
> - patched += size;
> }
>
> - return ret;
> }

Weren't these actively wrong before, if a non-ultimate
__patch_insn_set() failed we'd just ignore the error?

Reviewed-by: Conor Dooley <[email protected]>

Thanks,
Conor.

Attachments:

2024-04-24 10:47:55

by Conor Dooley

Subject: Re: [PATCH v2 4/7] riscv: Simplify text patching loops

On Wed, Apr 24, 2024 at 11:44:17AM +0100, Conor Dooley wrote:
> On Wed, Mar 27, 2024 at 09:04:43AM -0700, Samuel Holland wrote:
> > This reduces the number of variables and makes the code easier to parse.
> >
> > Signed-off-by: Samuel Holland <[email protected]>
> > ---
> >
> > Changes in v2:
> > - Further simplify patch_insn_set()/patch_insn_write() loop conditions
> > - Use min() instead of min_t() since both sides are unsigned long
> >
> > arch/riscv/kernel/patch.c | 37 +++++++++++++++++++++----------------
> > 1 file changed, 21 insertions(+), 16 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
> > index 9a1bce1adf5a..0d1700d1934c 100644
> > --- a/arch/riscv/kernel/patch.c
> > +++ b/arch/riscv/kernel/patch.c
> > @@ -155,22 +155,24 @@ NOKPROBE_SYMBOL(__patch_insn_write);
> >
> > static int patch_insn_set(void *addr, u8 c, size_t len)
> > {
> > - size_t patched = 0;
> > size_t size;
> > - int ret = 0;
> >
> > /*
> > * __patch_insn_set() can only work on 2 pages at a time so call it in a
> > * loop with len <= 2 * PAGE_SIZE.
> > */
> > - while (patched < len && !ret) {
> > - size = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(addr + patched), len - patched);
> > - ret = __patch_insn_set(addr + patched, c, size);
> > -
> > - patched += size;
> > }
> >
> > - return ret;
> > }
>
> Weren't these actively wrong before, if a non-ultimate
> __patch_insn_set() failed we'd just ignore the error?

nvm, failure to read on my part..

Attachments:

2024-04-24 10:49:56

by Conor Dooley

Subject: Re: [PATCH v2 5/7] riscv: Pass patch_text() the length in bytes

On Wed, Mar 27, 2024 at 09:04:44AM -0700, Samuel Holland wrote:
> patch_text_nosync() already handles an arbitrary length of code, so this
> removes a superfluous loop and reduces the number of icache flushes.
>
> Reviewed-by: Bj?rn T?pel <[email protected]>
> Signed-off-by: Samuel Holland <[email protected]>

Reviewed-by: Conor Dooley <[email protected]>

Attachments:

2024-04-24 10:51:31

by Conor Dooley

Subject: Re: [PATCH v2 6/7] riscv: Use offset_in_page() in text patching functions

On Wed, Mar 27, 2024 at 09:04:45AM -0700, Samuel Holland wrote:
> This is a bit easier to parse than the equivalent bit manipulation.

And it is used elsewhere in patch.c too, so makes things more consistent
to boot.
Reviewed-by: Conor Dooley <[email protected]>

Attachments:

2024-04-24 10:54:48

by Conor Dooley

Subject: Re: [PATCH v2 7/7] riscv: Remove extra variable in patch_text_nosync()

On Wed, Mar 27, 2024 at 09:04:46AM -0700, Samuel Holland wrote:
> This cast is superfluous, and is incorrect anyway if compressed
> instructions may be present.
>
> Reviewed-by: Bj?rn T?pel <[email protected]>
> Signed-off-by: Samuel Holland <[email protected]>

Reviewed-by: Conor Dooley <[email protected]>

Attachments: