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[PATCH v2 22/29] tcg: Return the map protection from alloc_code_gen_buff
From: |
Richard Henderson |
Subject: |
[PATCH v2 22/29] tcg: Return the map protection from alloc_code_gen_buffer |
Date: |
Sun, 14 Mar 2021 15:27:17 -0600 |
Change the interface from a boolean error indication to a
negative error vs a non-negative protection. For the moment
this is only interface change, not making use of the new data.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
tcg/region.c | 63 +++++++++++++++++++++++++++-------------------------
1 file changed, 33 insertions(+), 30 deletions(-)
diff --git a/tcg/region.c b/tcg/region.c
index 9a2b014838..3ca0d01fa4 100644
--- a/tcg/region.c
+++ b/tcg/region.c
@@ -521,14 +521,14 @@ static inline void split_cross_256mb(void **obuf, size_t
*osize,
static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE]
__attribute__((aligned(CODE_GEN_ALIGN)));
-static bool alloc_code_gen_buffer(size_t tb_size, int splitwx, Error **errp)
+static int alloc_code_gen_buffer(size_t tb_size, int splitwx, Error **errp)
{
void *buf, *end;
size_t size;
if (splitwx > 0) {
error_setg(errp, "jit split-wx not supported");
- return false;
+ return -1;
}
/* page-align the beginning and end of the buffer */
@@ -558,16 +558,17 @@ static bool alloc_code_gen_buffer(size_t tb_size, int
splitwx, Error **errp)
region.start_aligned = buf;
region.total_size = size;
- return true;
+
+ return PROT_READ | PROT_WRITE;
}
#elif defined(_WIN32)
-static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp)
+static int alloc_code_gen_buffer(size_t size, int splitwx, Error **errp)
{
void *buf;
if (splitwx > 0) {
error_setg(errp, "jit split-wx not supported");
- return false;
+ return -1;
}
buf = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT,
@@ -580,11 +581,12 @@ static bool alloc_code_gen_buffer(size_t size, int
splitwx, Error **errp)
region.start_aligned = buf;
region.total_size = size;
- return true;
+
+ return PAGE_READ | PAGE_WRITE | PAGE_EXEC;
}
#else
-static bool alloc_code_gen_buffer_anon(size_t size, int prot,
- int flags, Error **errp)
+static int alloc_code_gen_buffer_anon(size_t size, int prot,
+ int flags, Error **errp)
{
void *buf;
@@ -592,7 +594,7 @@ static bool alloc_code_gen_buffer_anon(size_t size, int
prot,
if (buf == MAP_FAILED) {
error_setg_errno(errp, errno,
"allocate %zu bytes for jit buffer", size);
- return false;
+ return -1;
}
#ifdef __mips__
@@ -633,7 +635,7 @@ static bool alloc_code_gen_buffer_anon(size_t size, int
prot,
region.start_aligned = buf;
region.total_size = size;
- return true;
+ return prot;
}
#ifndef CONFIG_TCG_INTERPRETER
@@ -647,9 +649,9 @@ static bool alloc_code_gen_buffer_splitwx_memfd(size_t
size, Error **errp)
#ifdef __mips__
/* Find space for the RX mapping, vs the 256MiB regions. */
- if (!alloc_code_gen_buffer_anon(size, PROT_NONE,
- MAP_PRIVATE | MAP_ANONYMOUS |
- MAP_NORESERVE, errp)) {
+ if (alloc_code_gen_buffer_anon(size, PROT_NONE,
+ MAP_PRIVATE | MAP_ANONYMOUS |
+ MAP_NORESERVE, errp) < 0) {
return false;
}
/* The size of the mapping may have been adjusted. */
@@ -683,7 +685,7 @@ static bool alloc_code_gen_buffer_splitwx_memfd(size_t
size, Error **errp)
/* Request large pages for the buffer and the splitwx. */
qemu_madvise(buf_rw, size, QEMU_MADV_HUGEPAGE);
qemu_madvise(buf_rx, size, QEMU_MADV_HUGEPAGE);
- return true;
+ return PROT_READ | PROT_WRITE;
fail_rx:
error_setg_errno(errp, errno, "failed to map shared memory for execute");
@@ -697,7 +699,7 @@ static bool alloc_code_gen_buffer_splitwx_memfd(size_t
size, Error **errp)
if (fd >= 0) {
close(fd);
}
- return false;
+ return -1;
}
#endif /* CONFIG_POSIX */
@@ -716,7 +718,7 @@ extern kern_return_t mach_vm_remap(vm_map_t target_task,
vm_prot_t *max_protection,
vm_inherit_t inheritance);
-static bool alloc_code_gen_buffer_splitwx_vmremap(size_t size, Error **errp)
+static int alloc_code_gen_buffer_splitwx_vmremap(size_t size, Error **errp)
{
kern_return_t ret;
mach_vm_address_t buf_rw, buf_rx;
@@ -725,7 +727,7 @@ static bool alloc_code_gen_buffer_splitwx_vmremap(size_t
size, Error **errp)
/* Map the read-write portion via normal anon memory. */
if (!alloc_code_gen_buffer_anon(size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, errp)) {
- return false;
+ return -1;
}
buf_rw = region.start_aligned;
@@ -745,23 +747,23 @@ static bool alloc_code_gen_buffer_splitwx_vmremap(size_t
size, Error **errp)
/* TODO: Convert "ret" to a human readable error message. */
error_setg(errp, "vm_remap for jit splitwx failed");
munmap((void *)buf_rw, size);
- return false;
+ return -1;
}
if (mprotect((void *)buf_rx, size, PROT_READ | PROT_EXEC) != 0) {
error_setg_errno(errp, errno, "mprotect for jit splitwx");
munmap((void *)buf_rx, size);
munmap((void *)buf_rw, size);
- return false;
+ return -1;
}
tcg_splitwx_diff = buf_rx - buf_rw;
- return true;
+ return PROT_READ | PROT_WRITE;
}
#endif /* CONFIG_DARWIN */
#endif /* CONFIG_TCG_INTERPRETER */
-static bool alloc_code_gen_buffer_splitwx(size_t size, Error **errp)
+static int alloc_code_gen_buffer_splitwx(size_t size, Error **errp)
{
#ifndef CONFIG_TCG_INTERPRETER
# ifdef CONFIG_DARWIN
@@ -772,24 +774,25 @@ static bool alloc_code_gen_buffer_splitwx(size_t size,
Error **errp)
# endif
#endif
error_setg(errp, "jit split-wx not supported");
- return false;
+ return -1;
}
-static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp)
+static int alloc_code_gen_buffer(size_t size, int splitwx, Error **errp)
{
ERRP_GUARD();
int prot, flags;
if (splitwx) {
- if (alloc_code_gen_buffer_splitwx(size, errp)) {
- return true;
+ prot = alloc_code_gen_buffer_splitwx(size, errp);
+ if (prot >= 0) {
+ return prot;
}
/*
* If splitwx force-on (1), fail;
* if splitwx default-on (-1), fall through to splitwx off.
*/
if (splitwx > 0) {
- return false;
+ return -1;
}
error_free_or_abort(errp);
}
@@ -844,11 +847,11 @@ void tcg_region_init(size_t tb_size, int splitwx,
unsigned max_cpus)
size_t region_size;
size_t i;
uintptr_t splitwx_diff;
- bool ok;
+ int have_prot;
- ok = alloc_code_gen_buffer(size_code_gen_buffer(tb_size),
- splitwx, &error_fatal);
- assert(ok);
+ have_prot = alloc_code_gen_buffer(size_code_gen_buffer(tb_size),
+ splitwx, &error_fatal);
+ assert(have_prot >= 0);
/*
* Make region_size a multiple of page_size, using aligned as the start.
--
2.25.1
- [PATCH v2 18/29] tcg: Tidy tcg_n_regions, (continued)
- [PATCH v2 18/29] tcg: Tidy tcg_n_regions, Richard Henderson, 2021/03/14
- [PATCH v2 23/29] tcg: Sink qemu_madvise call to common code, Richard Henderson, 2021/03/14
- [PATCH v2 26/29] tcg: Round the tb_size default from qemu_get_host_physmem, Richard Henderson, 2021/03/14
- [PATCH v2 24/29] tcg: Do not set guard pages in the rx buffer, Richard Henderson, 2021/03/14
- [PATCH v2 28/29] tcg: When allocating for !splitwx, begin with PROT_NONE, Richard Henderson, 2021/03/14
- [PATCH v2 29/29] tcg: Move tcg_init_ctx and tcg_ctx from accel/tcg/, Richard Henderson, 2021/03/14
- [PATCH v2 25/29] util/osdep: Add qemu_mprotect_rw, Richard Henderson, 2021/03/14
- [PATCH v2 21/29] tcg: Allocate code_gen_buffer into struct tcg_region_state, Richard Henderson, 2021/03/14
- [PATCH v2 27/29] tcg: Merge buffer protection and guard page protection, Richard Henderson, 2021/03/14
- [PATCH v2 22/29] tcg: Return the map protection from alloc_code_gen_buffer,
Richard Henderson <=
- Re: [PATCH v2 00/29] tcg: Workaround macOS 11.2 mprotect bug, no-reply, 2021/03/14
- Re: [PATCH v2 00/29] tcg: Workaround macOS 11.2 mprotect bug, Roman Bolshakov, 2021/03/15