diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0088-kprobes-x86-Disable-optimizing-on-the-function-jumps.patch')
-rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0088-kprobes-x86-Disable-optimizing-on-the-function-jumps.patch | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0088-kprobes-x86-Disable-optimizing-on-the-function-jumps.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0088-kprobes-x86-Disable-optimizing-on-the-function-jumps.patch new file mode 100644 index 00000000..cac6deac --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0088-kprobes-x86-Disable-optimizing-on-the-function-jumps.patch @@ -0,0 +1,83 @@ +From fdeb7a1f0247fca891d02ce491582ba950f7ee15 Mon Sep 17 00:00:00 2001 +From: Masami Hiramatsu <mhiramat@kernel.org> +Date: Fri, 19 Jan 2018 01:15:20 +0900 +Subject: [PATCH 088/103] kprobes/x86: Disable optimizing on the function jumps + to indirect thunk + +commit c86a32c09f8ced67971a2310e3b0dda4d1749007 upstream. + +Since indirect jump instructions will be replaced by jump +to __x86_indirect_thunk_*, those jmp instruction must be +treated as an indirect jump. Since optprobe prohibits to +optimize probes in the function which uses an indirect jump, +it also needs to find out the function which jump to +__x86_indirect_thunk_* and disable optimization. + +Add a check that the jump target address is between the +__indirect_thunk_start/end when optimizing kprobe. + +Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Acked-by: David Woodhouse <dwmw@amazon.co.uk> +Cc: Andi Kleen <ak@linux.intel.com> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> +Cc: Arjan van de Ven <arjan@linux.intel.com> +Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> +Link: https://lkml.kernel.org/r/151629212062.10241.6991266100233002273.stgit@devbox +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kernel/kprobes/opt.c | 23 ++++++++++++++++++++++- + 1 file changed, 22 insertions(+), 1 deletion(-) + +diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c +index 3bb4c5f..90f8cd6 100644 +--- a/arch/x86/kernel/kprobes/opt.c ++++ b/arch/x86/kernel/kprobes/opt.c +@@ -37,6 +37,7 @@ + #include <asm/alternative.h> + #include <asm/insn.h> + #include <asm/debugreg.h> ++#include <asm/nospec-branch.h> + + #include "common.h" + +@@ -192,7 +193,7 @@ static int copy_optimized_instructions(u8 *dest, u8 *src) + } + + /* Check whether insn is indirect jump */ +-static int insn_is_indirect_jump(struct insn *insn) ++static int __insn_is_indirect_jump(struct insn *insn) + { + return ((insn->opcode.bytes[0] == 0xff && + (X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */ +@@ -226,6 +227,26 @@ static int insn_jump_into_range(struct insn *insn, unsigned long start, int len) + return (start <= target && target <= start + len); + } + ++static int insn_is_indirect_jump(struct insn *insn) ++{ ++ int ret = __insn_is_indirect_jump(insn); ++ ++#ifdef CONFIG_RETPOLINE ++ /* ++ * Jump to x86_indirect_thunk_* is treated as an indirect jump. ++ * Note that even with CONFIG_RETPOLINE=y, the kernel compiled with ++ * older gcc may use indirect jump. So we add this check instead of ++ * replace indirect-jump check. ++ */ ++ if (!ret) ++ ret = insn_jump_into_range(insn, ++ (unsigned long)__indirect_thunk_start, ++ (unsigned long)__indirect_thunk_end - ++ (unsigned long)__indirect_thunk_start); ++#endif ++ return ret; ++} ++ + /* Decode whole function to ensure any instructions don't jump into target */ + static int can_optimize(unsigned long paddr) + { +-- +2.7.4 + |