Page MenuHomeFreeBSD
Files F152349711

D11780.id31351.diff
No OneTemporary
Actions

D11780.id31351.diff
View Options

Index: sys/amd64/amd64/elf_machdep.c
===================================================================
--- sys/amd64/amd64/elf_machdep.c
+++ sys/amd64/amd64/elf_machdep.c
@@ -46,6 +46,7 @@
#include <machine/elf.h>
#include <machine/fpu.h>
#include <machine/md_var.h>
+void amd64_lower_shared_page(struct sysentvec *);
struct sysentvec elf64_freebsd_sysvec = {
.sv_size = SYS_MAXSYSCALL,
@@ -84,6 +85,20 @@
};
INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
+void
+amd64_lower_shared_page(struct sysentvec *sv)
+{
+ if (hw_lower_amd64_sharedpage != 0) {
+ sv->sv_shared_page_base -= PAGE_SIZE;
+ sv->sv_usrstack -= PAGE_SIZE;
+ sv->sv_psstrings -= PAGE_SIZE;
+ }
+}
+
+SYSINIT(elf64_sysvec_fixup, SI_SUB_EXEC, SI_ORDER_FIRST,
+ (sysinit_cfunc_t) amd64_lower_shared_page,
+ &elf64_freebsd_sysvec);
+
static Elf64_Brandinfo freebsd_brand_info = {
.brand = ELFOSABI_FREEBSD,
.machine = EM_X86_64,
@@ -96,7 +111,7 @@
.flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
};
-SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
+SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_SECOND,
(sysinit_cfunc_t) elf64_insert_brand_entry,
&freebsd_brand_info);
Index: sys/amd64/amd64/initcpu.c
===================================================================
--- sys/amd64/amd64/initcpu.c
+++ sys/amd64/amd64/initcpu.c
@@ -48,6 +48,11 @@
static int hw_instruction_sse;
SYSCTL_INT(_hw, OID_AUTO, instruction_sse, CTLFLAG_RD,
&hw_instruction_sse, 0, "SIMD/MMX2 instructions available in CPU");
+static int lower_sharedpage_init;
+int hw_lower_amd64_sharedpage;
+SYSCTL_INT(_hw, OID_AUTO, lower_amd64_sharedpage, CTLFLAG_RDTUN,
+ &hw_lower_amd64_sharedpage, 0,
+ "Lower sharedpage to work around Ryzen issue with executing code near the top of user memory");
/*
* -1: automatic (default)
* 0: keep enable CLFLUSH
@@ -120,6 +125,28 @@
msr = rdmsr(0xc0011020);
msr |= (uint64_t)1 << 15;
wrmsr(0xc0011020, msr);
+ }
+ }
+
+ /*
+ * Work around a problem on Ryzen that is triggered by executing
+ * code near the top of user memory, in our case the signal
+ * trampoline code in the shared page on amd64.
+ *
+ * This function is executed once for the BSP before tunables take
+ * effect so the value determined here can be overridden by the
+ * tunable. This function is then then executed again for each AP
+ * and also on resume, so set a flag so that value set by the tunable
+ * is not overwritten.
+ *
+ * The stepping and/or microcode versions should be checked after
+ * this issue is fixed by AMD so that we don't use this mode if not
+ * needed.
+ */
+ if (lower_sharedpage_init == 0) {
+ lower_sharedpage_init = 1;
+ if (CPUID_TO_FAMILY(cpu_id) == 0x17) {
+ hw_lower_amd64_sharedpage = 1;
}
}
}
Index: sys/amd64/include/md_var.h
===================================================================
--- sys/amd64/include/md_var.h
+++ sys/amd64/include/md_var.h
@@ -34,7 +34,8 @@
#include <x86/x86_var.h>
-extern uint64_t *vm_page_dump;
+extern uint64_t *vm_page_dump;
+extern int hw_lower_amd64_sharedpage;
struct savefpu;
Index: sys/amd64/linux/linux_sysvec.c
===================================================================
--- sys/amd64/linux/linux_sysvec.c
+++ sys/amd64/linux/linux_sysvec.c
@@ -85,6 +85,8 @@
#include <compat/linux/linux_util.h>
#include <compat/linux/linux_vdso.h>
+void amd64_lower_shared_page(struct sysentvec *);
+
MODULE_VERSION(linux64, 1);
#if BYTE_ORDER == LITTLE_ENDIAN
@@ -833,6 +835,8 @@
linux_vdso_install(void *param)
{
+ amd64_lower_shared_page(&elf_linux_sysvec);
+
linux_szsigcode = (&_binary_linux_locore_o_end -
&_binary_linux_locore_o_start);
@@ -844,14 +848,15 @@
linux_shared_page_obj = __elfN(linux_shared_page_init)
(&linux_shared_page_mapping);
- __elfN(linux_vdso_reloc)(&elf_linux_sysvec, SHAREDPAGE);
+ __elfN(linux_vdso_reloc)(&elf_linux_sysvec,
+ elf_linux_sysvec.sv_shared_page_base);
bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
linux_szsigcode);
elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
linux_kplatform = linux_shared_page_mapping +
- (linux_platform - (caddr_t)SHAREDPAGE);
+ (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base);
}
SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
(sysinit_cfunc_t)linux_vdso_install, NULL);

File Metadata

Mime Type
text/plain
Expires
Wed, Apr 15, 8:51 AM (11 h, 36 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
31530287
Default Alt Text
D11780.id31351.diff (4 KB)

Event Timeline