diff options
| author | Doug Anderson <dianders@chromium.org> | 2014-04-22 15:14:51 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2014-10-16 14:38:53 -0700 |
| commit | 23a4e4050ba9c98ab67db0980a9fb20e5096d9ea (patch) | |
| tree | a5571f323a6f923d5b8d4674112eec798f0bb13b /arch | |
| parent | 42d720d1731a9d7035c2812437c35e271ec4dd78 (diff) | |
| download | linux-23a4e4050ba9c98ab67db0980a9fb20e5096d9ea.tar.bz2 | |
arm: kgdb: Handle read-only text / modules
Handle the case where someone has set the text segment of the kernel
as read-only by using the newly introduced "patch" mechanism.
Signed-off-by: Doug Anderson <dianders@chromium.org>
[kees: switched structure size check to BUILD_BUG_ON (sboyd)]
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/kgdb.c | 29 |
2 files changed, 30 insertions, 1 deletions
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 38ddd9f83d0e..70b730766330 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -67,7 +67,7 @@ test-kprobes-objs += kprobes-test-arm.o endif obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_ARM_THUMBEE) += thumbee.o -obj-$(CONFIG_KGDB) += kgdb.o +obj-$(CONFIG_KGDB) += kgdb.o patch.o obj-$(CONFIG_ARM_UNWIND) += unwind.o obj-$(CONFIG_HAVE_TCM) += tcm.o obj-$(CONFIG_OF) += devtree.o diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index a74b53c1b7df..07db2f8a1b45 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -12,8 +12,12 @@ #include <linux/irq.h> #include <linux/kdebug.h> #include <linux/kgdb.h> +#include <linux/uaccess.h> + #include <asm/traps.h> +#include "patch.h" + struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { { "r0", 4, offsetof(struct pt_regs, ARM_r0)}, @@ -244,6 +248,31 @@ void kgdb_arch_exit(void) unregister_die_notifier(&kgdb_notifier); } +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) +{ + int err; + + /* patch_text() only supports int-sized breakpoints */ + BUILD_BUG_ON(sizeof(int) != BREAK_INSTR_SIZE); + + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, + BREAK_INSTR_SIZE); + if (err) + return err; + + patch_text((void *)bpt->bpt_addr, + *(unsigned int *)arch_kgdb_ops.gdb_bpt_instr); + + return err; +} + +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) +{ + patch_text((void *)bpt->bpt_addr, *(unsigned int *)bpt->saved_instr); + + return 0; +} + /* * Register our undef instruction hooks with ARM undef core. * We regsiter a hook specifically looking for the KGB break inst |