[PATCH 0/3] More objtool fixes

[PATCH 0/3] More objtool fixes

[Josh Poimboeuf]

Patch 1 fixes an objtool seg fault which was seen in the error path of
another bug fixed by patch 2.

Patch 3 removes an unnecessary function ignore for ORC.

Josh Poimboeuf (3):
  objtool: Fix seg fault in ignore_unreachable_insn()
  objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions
  objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC

 drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 2 +-
 tools/objtool/check.c               | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

-- 
2.48.1

[PATCH 1/3] objtool: Fix seg fault in ignore_unreachable_insn()

[Josh Poimboeuf]

Check prev_insn before dereferencing it.

Fixes: bd841d6154f5 ("objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/d86b4cc6-0b97-4095-8793-a7384410b8ab@app.fastmail.com
Reported-by: Ingo Molnar <mingo@kernel.org>
Closes: https://lore.kernel.org/Z-V_rruKY0-36pqA@gmail.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3bf29923d5c0..29de1709ea00 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4037,7 +4037,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
 	 * It may also insert a UD2 after calling a __noreturn function.
 	 */
 	prev_insn = prev_insn_same_sec(file, insn);
-	if (prev_insn->dead_end &&
+	if (prev_insn && prev_insn->dead_end &&
 	    (insn->type == INSN_BUG ||
 	     (insn->type == INSN_JUMP_UNCONDITIONAL &&
 	      insn->jump_dest && insn->jump_dest->type == INSN_BUG)))
-- 
2.48.1

[PATCH 2/3] objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions

[Josh Poimboeuf]

The recent STACK_FRAME_NON_STANDARD refactoring forgot about .cold
subfunctions.  They must also be ignored.

Fixes the following warning:

  drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_recv_msg.cold+0x0: unreachable instruction

Fixes: c84301d706c5 ("objtool: Ignore entire functions rather than instructions")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 29de1709ea00..fff9d7a2947a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1014,6 +1014,8 @@ static int add_ignores(struct objtool_file *file)
 		}
 
 		func->ignore = true;
+		if (func->cfunc)
+			func->cfunc->ignore = true;
 	}
 
 	return 0;
-- 
2.48.1

[PATCH 3/3] objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC

[Josh Poimboeuf]

The following commit:

  0b0d81e3b733 ("objtool, drm/vmwgfx: Fix "duplicate frame pointer save" warning")

... marked vmw_send_msg() STACK_FRAME_NON_STANDARD because it uses RBP
in a non-standard way which violates frame pointer convention.

That issue only affects the frame pointer unwinder.  Remove the
annotation for ORC.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
index 1f15990d3934..1d9a42cbc88f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -289,7 +289,7 @@ static int vmw_send_msg(struct rpc_channel *channel, const char *msg)
 
 	return -EINVAL;
 }
-STACK_FRAME_NON_STANDARD(vmw_send_msg);
+STACK_FRAME_NON_STANDARD_FP(vmw_send_msg);
 
 
 /**
-- 
2.48.1

[tip: objtool/urgent] objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     ae958b12940bcd4ffa32c44684e4f2878bc5e140
Gitweb:        https://git.kernel.org/tip/ae958b12940bcd4ffa32c44684e4f2878bc5e140
Author:        Josh Poimboeuf <jpoimboe@kernel.org>
AuthorDate:    Thu, 27 Mar 2025 22:04:23 -07:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 28 Mar 2025 14:47:02 +01:00

objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC

The following commit:

  0b0d81e3b733 ("objtool, drm/vmwgfx: Fix "duplicate frame pointer save" warning")

... marked vmw_send_msg() STACK_FRAME_NON_STANDARD because it uses RBP
in a non-standard way which violates frame pointer convention.

That issue only affects the frame pointer unwinder.  Remove the
annotation for ORC.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/eff3102a7eeb77b4420fcb5e9d9cd9dd81d4514a.1743136205.git.jpoimboe@kernel.org
---
 drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
index 1f15990..1d9a42c 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -289,7 +289,7 @@ static int vmw_send_msg(struct rpc_channel *channel, const char *msg)
 
 	return -EINVAL;
 }
-STACK_FRAME_NON_STANDARD(vmw_send_msg);
+STACK_FRAME_NON_STANDARD_FP(vmw_send_msg);
 
 
 /**

[tip: objtool/urgent] objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     b5e2cc57f551a1a1e2c0ea36f77c1e26d3d13c35
Gitweb:        https://git.kernel.org/tip/b5e2cc57f551a1a1e2c0ea36f77c1e26d3d13c35
Author:        Josh Poimboeuf <jpoimboe@kernel.org>
AuthorDate:    Thu, 27 Mar 2025 22:04:22 -07:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 28 Mar 2025 14:47:02 +01:00

objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions

The recent STACK_FRAME_NON_STANDARD refactoring forgot about .cold
subfunctions.  They must also be ignored.

Fixes the following warning:

  drivers/gpu/drm/vmwgfx/vmwgfx_msg.o: warning: objtool: vmw_recv_msg.cold+0x0: unreachable instruction

Fixes: c84301d706c5 ("objtool: Ignore entire functions rather than instructions")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/70a09ec0b0704398b2bbfb3153ce3d7cb8a381be.1743136205.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 29de170..fff9d7a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1014,6 +1014,8 @@ static int add_ignores(struct objtool_file *file)
 		}
 
 		func->ignore = true;
+		if (func->cfunc)
+			func->cfunc->ignore = true;
 	}
 
 	return 0;

[tip: objtool/urgent] objtool: Fix segfault in ignore_unreachable_insn()

[tip-bot2 for Josh Poimboeuf]

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     69d41d6dafff0967565b971d950bd10443e4076c
Gitweb:        https://git.kernel.org/tip/69d41d6dafff0967565b971d950bd10443e4076c
Author:        Josh Poimboeuf <jpoimboe@kernel.org>
AuthorDate:    Thu, 27 Mar 2025 22:04:21 -07:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 28 Mar 2025 14:47:02 +01:00

objtool: Fix segfault in ignore_unreachable_insn()

Check 'prev_insn' before dereferencing it.

Fixes: bd841d6154f5 ("objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/5df4ff89c9e4b9e788b77b0531234ffa7ba03e9e.1743136205.git.jpoimboe@kernel.org

Closes: https://lore.kernel.org/d86b4cc6-0b97-4095-8793-a7384410b8ab@app.fastmail.com
Closes: https://lore.kernel.org/Z-V_rruKY0-36pqA@gmail.com
---
 tools/objtool/check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3bf2992..29de170 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4037,7 +4037,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
 	 * It may also insert a UD2 after calling a __noreturn function.
 	 */
 	prev_insn = prev_insn_same_sec(file, insn);
-	if (prev_insn->dead_end &&
+	if (prev_insn && prev_insn->dead_end &&
 	    (insn->type == INSN_BUG ||
 	     (insn->type == INSN_JUMP_UNCONDITIONAL &&
 	      insn->jump_dest && insn->jump_dest->type == INSN_BUG)))