|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v1 09/11] xsplice: Add support for bug frames
Add support for handling bug frames contained with xsplice modules. If a
trap occurs search either the kernel bug table or an applied module's
bug table depending on the instruction pointer.
Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
---
xen/arch/x86/traps.c | 30 ++++++++-----
xen/common/symbols.c | 7 +++
xen/common/xsplice.c | 107 +++++++++++++++++++++++++++++++++++++++++-----
xen/include/xen/kernel.h | 1 +
xen/include/xen/xsplice.h | 4 ++
5 files changed, 129 insertions(+), 20 deletions(-)
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index b32f696..cd51cfd 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -48,6 +48,7 @@
#include <xen/kexec.h>
#include <xen/trace.h>
#include <xen/paging.h>
+#include <xen/xsplice.h>
#include <xen/watchdog.h>
#include <asm/system.h>
#include <asm/io.h>
@@ -1076,20 +1077,29 @@ void do_invalid_op(struct cpu_user_regs *regs)
return;
}
- if ( !is_active_kernel_text(regs->eip) ||
+ if ( !is_active_text(regs->eip) ||
__copy_from_user(bug_insn, eip, sizeof(bug_insn)) ||
memcmp(bug_insn, "\xf\xb", sizeof(bug_insn)) )
goto die;
- for ( bug = __start_bug_frames, id = 0; stop_frames[id]; ++bug )
+ if ( likely(is_active_kernel_text(regs->eip)) )
{
- while ( unlikely(bug == stop_frames[id]) )
- ++id;
- if ( bug_loc(bug) == eip )
- break;
+ for ( bug = __start_bug_frames, id = 0; stop_frames[id]; ++bug )
+ {
+ while ( unlikely(bug == stop_frames[id]) )
+ ++id;
+ if ( bug_loc(bug) == eip )
+ break;
+ }
+ if ( !stop_frames[id] )
+ goto die;
+ }
+ else
+ {
+ bug = xsplice_find_bug(eip, &id);
+ if ( !bug )
+ goto die;
}
- if ( !stop_frames[id] )
- goto die;
eip += sizeof(bug_insn);
if ( id == BUGFRAME_run_fn )
@@ -1103,7 +1113,7 @@ void do_invalid_op(struct cpu_user_regs *regs)
/* WARN, BUG or ASSERT: decode the filename pointer and line number. */
filename = bug_ptr(bug);
- if ( !is_kernel(filename) )
+ if ( !is_kernel(filename) && !is_module(filename) )
goto die;
fixup = strlen(filename);
if ( fixup > 50 )
@@ -1130,7 +1140,7 @@ void do_invalid_op(struct cpu_user_regs *regs)
case BUGFRAME_assert:
/* ASSERT: decode the predicate string pointer. */
predicate = bug_msg(bug);
- if ( !is_kernel(predicate) )
+ if ( !is_kernel(predicate) && !is_module(predicate) )
predicate = "<unknown>";
printk("Assertion '%s' failed at %s%s:%d\n",
diff --git a/xen/common/symbols.c b/xen/common/symbols.c
index a59c59d..bf5623f 100644
--- a/xen/common/symbols.c
+++ b/xen/common/symbols.c
@@ -17,6 +17,7 @@
#include <xen/lib.h>
#include <xen/string.h>
#include <xen/spinlock.h>
+#include <xen/xsplice.h>
#include <public/platform.h>
#include <xen/guest_access.h>
@@ -101,6 +102,12 @@ bool_t is_active_kernel_text(unsigned long addr)
(system_state < SYS_STATE_active && is_kernel_inittext(addr)));
}
+bool_t is_active_text(unsigned long addr)
+{
+ return is_active_kernel_text(addr) ||
+ is_active_module_text(addr);
+}
+
const char *symbols_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
diff --git a/xen/common/xsplice.c b/xen/common/xsplice.c
index 4476be5..982954b 100644
--- a/xen/common/xsplice.c
+++ b/xen/common/xsplice.c
@@ -40,6 +40,11 @@ struct payload {
int nfuncs;
void *module_address;
size_t module_pages;
+ size_t core_size;
+ size_t core_text_size;
+
+ struct bug_frame *start_bug_frames[4];
+ struct bug_frame *stop_bug_frames[4];
char id[XEN_XSPLICE_NAME_SIZE + 1]; /* Name of it. */
};
@@ -525,26 +530,27 @@ static void free_module(struct payload *payload)
payload->module_pages = 0;
}
-static void alloc_section(struct xsplice_elf_sec *sec, size_t *core_size)
+static void alloc_section(struct xsplice_elf_sec *sec, size_t *size)
{
- size_t align_size = ROUNDUP(*core_size, sec->sec->sh_addralign);
+ size_t align_size = ROUNDUP(*size, sec->sec->sh_addralign);
sec->sec->sh_entsize = align_size;
- *core_size = sec->sec->sh_size + align_size;
+ *size = sec->sec->sh_size + align_size;
}
static int move_module(struct payload *payload, struct xsplice_elf *elf)
{
uint8_t *buf;
int i;
- size_t core_size = 0;
+ size_t size = 0;
/* Allocate text regions */
for ( i = 0; i < elf->hdr->e_shnum; i++ )
{
if ( (elf->sec[i].sec->sh_flags & (SHF_ALLOC|SHF_EXECINSTR)) ==
(SHF_ALLOC|SHF_EXECINSTR) )
- alloc_section(&elf->sec[i], &core_size);
+ alloc_section(&elf->sec[i], &size);
}
+ payload->core_text_size = size;
/* Allocate rw data */
for ( i = 0; i < elf->hdr->e_shnum; i++ )
@@ -552,7 +558,7 @@ static int move_module(struct payload *payload, struct
xsplice_elf *elf)
if ( (elf->sec[i].sec->sh_flags & SHF_ALLOC) &&
!(elf->sec[i].sec->sh_flags & SHF_EXECINSTR) &&
(elf->sec[i].sec->sh_flags & SHF_WRITE) )
- alloc_section(&elf->sec[i], &core_size);
+ alloc_section(&elf->sec[i], &size);
}
/* Allocate ro data */
@@ -561,15 +567,16 @@ static int move_module(struct payload *payload, struct
xsplice_elf *elf)
if ( (elf->sec[i].sec->sh_flags & SHF_ALLOC) &&
!(elf->sec[i].sec->sh_flags & SHF_EXECINSTR) &&
!(elf->sec[i].sec->sh_flags & SHF_WRITE) )
- alloc_section(&elf->sec[i], &core_size);
+ alloc_section(&elf->sec[i], &size);
}
+ payload->core_size = size;
- buf = alloc_module(core_size);
+ buf = alloc_module(size);
if ( !buf ) {
printk(XENLOG_ERR "Could not allocate memory for module\n");
return -ENOMEM;
}
- memset(buf, 0, core_size);
+ memset(buf, 0, size);
for ( i = 0; i < elf->hdr->e_shnum; i++ )
{
@@ -584,7 +591,7 @@ static int move_module(struct payload *payload, struct
xsplice_elf *elf)
}
payload->module_address = buf;
- payload->module_pages = PFN_UP(core_size);
+ payload->module_pages = PFN_UP(size);
return 0;
}
@@ -659,6 +666,7 @@ static int find_special_sections(struct payload *payload,
struct xsplice_elf *elf)
{
struct xsplice_elf_sec *sec;
+ int i;
sec = xsplice_elf_sec_by_name(elf, ".xsplice.funcs");
if ( !sec )
@@ -670,6 +678,19 @@ static int find_special_sections(struct payload *payload,
payload->funcs = (struct xsplice_patch_func *)sec->load_addr;
payload->nfuncs = sec->sec->sh_size / (sizeof *payload->funcs);
+ for ( i = 0; i < 4; i++ )
+ {
+ char str[14];
+
+ snprintf(str, sizeof str, ".bug_frames.%d", i);
+ sec = xsplice_elf_sec_by_name(elf, str);
+ if ( !sec )
+ continue;
+
+ payload->start_bug_frames[i] = (struct bug_frame *)sec->load_addr;
+ payload->stop_bug_frames[i] = (struct bug_frame *)(sec->load_addr +
sec->sec->sh_size);
+ }
+
return 0;
}
@@ -912,6 +933,72 @@ void do_xsplice(void)
}
}
+
+/*
+ * Functions for handling special sections.
+ */
+struct bug_frame *xsplice_find_bug(const char *eip, int *id)
+{
+ struct payload *data;
+ struct bug_frame *bug;
+ int i;
+
+ /* No locking since this list is only ever changed during apply or revert
+ * context. */
+ list_for_each_entry ( data, &applied_list, applied_list )
+ {
+ for (i = 0; i < 4; i++) {
+ if (!data->start_bug_frames[i])
+ continue;
+ if ( !((void *)eip >= data->module_address &&
+ (void *)eip < (data->module_address +
data->core_text_size)))
+ continue;
+
+ for ( bug = data->start_bug_frames[i]; bug !=
data->stop_bug_frames[i]; ++bug ) {
+ if ( bug_loc(bug) == eip )
+ {
+ *id = i;
+ return bug;
+ }
+ }
+ }
+ }
+
+ return NULL;
+}
+
+bool_t is_module(const void *ptr)
+{
+ struct payload *data;
+
+ /* No locking since this list is only ever changed during apply or revert
+ * context. */
+ list_for_each_entry ( data, &applied_list, applied_list )
+ {
+ if ( ptr >= data->module_address &&
+ ptr < (data->module_address + data->core_size))
+ return true;
+ }
+
+ return false;
+}
+
+bool_t is_active_module_text(unsigned long addr)
+{
+ struct payload *data;
+
+ /* No locking since this list is only ever changed during apply or revert
+ * context. */
+ list_for_each_entry ( data, &applied_list, applied_list )
+ {
+ if ( (void *)addr >= data->module_address &&
+ (void *)addr < (data->module_address + data->core_text_size))
+ return true;
+ }
+
+ return false;
+}
+
static int __init xsplice_init(void)
{
register_keyhandler('x', xsplice_printall, "print xsplicing info", 1);
diff --git a/xen/include/xen/kernel.h b/xen/include/xen/kernel.h
index 548b64d..df57754 100644
--- a/xen/include/xen/kernel.h
+++ b/xen/include/xen/kernel.h
@@ -99,6 +99,7 @@ extern enum system_state {
} system_state;
bool_t is_active_kernel_text(unsigned long addr);
+bool_t is_active_text(unsigned long addr);
#endif /* _LINUX_KERNEL_H */
diff --git a/xen/include/xen/xsplice.h b/xen/include/xen/xsplice.h
index 507829c..772fa3a 100644
--- a/xen/include/xen/xsplice.h
+++ b/xen/include/xen/xsplice.h
@@ -22,6 +22,10 @@ extern void xsplice_printall(unsigned char key);
void do_xsplice(void);
+struct bug_frame * xsplice_find_bug(const char *eip, int *id);
+bool_t is_module(const void *addr);
+bool_t is_active_module_text(unsigned long addr);
+
/* Arch hooks */
int xsplice_verify_elf(uint8_t *data, ssize_t len);
int xsplice_perform_rel(struct xsplice_elf *elf,
--
2.4.3
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |