Unverified Commit 3f6af508 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
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!977 [sync] PR-968: Fix ORC unwinder on paravirt {save,restore}_fl 

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/968 
 
PR sync from:  Chen Zhongjin <chenzhongjin@huawei.com>
 https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/thread/C2NOJBSCQVMEFEIEDAK3YKPNYQ67TO7J/ 
ISSUE: gitee.com/openeuler/kernel/issues/I6DK3O

Chen Zhongjin (2):
  x86/unwind: Fix orc entry for paravirt {save,restore}_fl
  x86/unwind: Fix check_paravirt() calls orc_find() before declaration


-- 
2.17.1
 
 
Link:https://gitee.com/openeuler/kernel/pulls/977

 

Reviewed-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents b8e1d215 b46958a8

arch/x86/kernel/unwind_orc.c

+44 −1
Original line number Diff line number Diff line
@@ -77,9 +77,9 @@ static struct orc_entry *orc_module_find(unsigned long ip) 
}

#endif



#ifdef CONFIG_DYNAMIC_FTRACE

static struct orc_entry *orc_find(unsigned long ip);



#ifdef CONFIG_DYNAMIC_FTRACE

/*

 * Ftrace dynamic trampolines do not have orc entries of their own.

 * But they are copies of the ftrace entries that are static and
@@ -146,6 +146,34 @@ static struct orc_entry orc_fp_entry = { 
	.end		= 0,

};



#ifdef CONFIG_PARAVIRT_XXL

static bool check_paravirt(struct unwind_state *state, struct orc_entry *orc)

{

	u8 *ip = (u8 *)state->ip;



	/*

	 * In paravirt_patch.c, patched paravirt opcode should be:

	 * pushfq; popq %rax // 0x9c 0x58

	 * pushq %rdi; popfq // 0x57 0x9d

	 *

	 * Error unwinding only happens when:

	 * 1. In irq or preempt context.

	 * 2. Current insn is popq, and it doesn't change orc.

	 * 3. Last insn doesn't change orc, checking it first to

	 *    promise ip - 1 is valid.

	 * 4. Last byte fits pushf.

	 */

	if (state->regs && orc->type == UNWIND_HINT_TYPE_CALL &&

		(ip[0] == 0x58 || ip[0] == 0x9d) &&

		orc == orc_find((unsigned long)(ip + 1)) &&

		orc == orc_find((unsigned long)(ip - 1)) &&

		(ip[-1] == 0x9c || ip[-1] == 0x57))

		return true;



	return false;

}

#endif



static struct orc_entry *orc_find(unsigned long ip)

{

	static struct orc_entry *orc;
@@ -425,6 +453,9 @@ bool unwind_next_frame(struct unwind_state *state) 
	enum stack_type prev_type = state->stack_info.type;

	struct orc_entry *orc;

	bool indirect = false;

#ifdef CONFIG_PARAVIRT_XXL

	struct orc_entry para_orc;

#endif



	if (unwind_done(state))

		return false;
@@ -457,6 +488,18 @@ bool unwind_next_frame(struct unwind_state *state) 
		state->error = true;

	}



#ifdef CONFIG_PARAVIRT_XXL

	/*

	 * When hitting paravirt POP insn, the orc entry should add

	 * one slot for PUSH insn.

	 */

	if (!state->error && check_paravirt(state, orc)) {

		para_orc = *orc;

		para_orc.sp_offset += sizeof(long);

		orc = &para_orc;

	}

#endif



	/* End-of-stack check for kernel threads: */

	if (orc->sp_reg == ORC_REG_UNDEFINED) {

		if (!orc->end)