Commit 5b129817 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Borislav Petkov:

 - Two fixes to correct how kprobes handles INT3 now that they're added
   by other functionality like the rethunks and not only kgdb

 - Remove __init section markings of two functions which are referenced
   by a function in the .text section

* tag 'x86_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix optprobe optimization check with CONFIG_RETHUNK
  x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK
  x86/calldepth: Fix incorrect init section references
parents 95d248d1 63dc6325

arch/x86/kernel/callthunks.c

+2 −2
Original line number Diff line number Diff line
@@ -119,7 +119,7 @@ static bool is_coretext(const struct core_text *ct, void *addr) 
	return within_module_coretext(addr);

}



static __init_or_module bool skip_addr(void *dest)

static bool skip_addr(void *dest)

{

	if (dest == error_entry)

		return true;
@@ -181,7 +181,7 @@ static const u8 nops[] = { 
	0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,

};



static __init_or_module void *patch_dest(void *dest, bool direct)

static void *patch_dest(void *dest, bool direct)

{

	unsigned int tsize = SKL_TMPL_SIZE;

	u8 *pad = dest - tsize;

arch/x86/kernel/kprobes/core.c

+7 −3
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include <linux/extable.h>

#include <linux/kdebug.h>

#include <linux/kallsyms.h>

#include <linux/kgdb.h>

#include <linux/ftrace.h>

#include <linux/kasan.h>

#include <linux/moduleloader.h>
@@ -281,12 +282,15 @@ static int can_probe(unsigned long paddr) 
		if (ret < 0)

			return 0;



#ifdef CONFIG_KGDB

		/*

		 * Another debugging subsystem might insert this breakpoint.

		 * In that case, we can't recover it.

		 * If there is a dynamically installed kgdb sw breakpoint,

		 * this function should not be probed.

		 */

		if (insn.opcode.bytes[0] == INT3_INSN_OPCODE)

		if (insn.opcode.bytes[0] == INT3_INSN_OPCODE &&

		    kgdb_has_hit_break(addr))

			return 0;

#endif

		addr += insn.length;

	}

arch/x86/kernel/kprobes/opt.c

+8 −20
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/extable.h>

#include <linux/kdebug.h>

#include <linux/kallsyms.h>

#include <linux/kgdb.h>

#include <linux/ftrace.h>

#include <linux/objtool.h>

#include <linux/pgtable.h>
@@ -279,19 +280,6 @@ static int insn_is_indirect_jump(struct insn *insn) 
	return ret;

}



static bool is_padding_int3(unsigned long addr, unsigned long eaddr)

{

	unsigned char ops;



	for (; addr < eaddr; addr++) {

		if (get_kernel_nofault(ops, (void *)addr) < 0 ||

		    ops != INT3_INSN_OPCODE)

			return false;

	}



	return true;

}



/* Decode whole function to ensure any instructions don't jump into target */

static int can_optimize(unsigned long paddr)

{
@@ -334,15 +322,15 @@ static int can_optimize(unsigned long paddr) 
		ret = insn_decode_kernel(&insn, (void *)recovered_insn);

		if (ret < 0)

			return 0;



#ifdef CONFIG_KGDB

		/*

		 * In the case of detecting unknown breakpoint, this could be

		 * a padding INT3 between functions. Let's check that all the

		 * rest of the bytes are also INT3.

		 * If there is a dynamically installed kgdb sw breakpoint,

		 * this function should not be probed.

		 */

		if (insn.opcode.bytes[0] == INT3_INSN_OPCODE)

			return is_padding_int3(addr, paddr - offset + size) ? 1 : 0;



		if (insn.opcode.bytes[0] == INT3_INSN_OPCODE &&

		    kgdb_has_hit_break(addr))

			return 0;

#endif

		/* Recover address */

		insn.kaddr = (void *)addr;

		insn.next_byte = (void *)(addr + insn.length);