git: 187a63535228 - stable/13 - linux: adjust ordering of Linux auxv and add dummy AT_HWCAP2

From: Edward Tomasz Napierala <trasz_at_FreeBSD.org>
Date: Thu, 17 Feb 2022 10:55:24 UTC
The branch stable/13 has been updated by trasz:

URL: https://cgit.FreeBSD.org/src/commit/?id=187a635352288a11735c095690b36a2583d5701d

commit 187a635352288a11735c095690b36a2583d5701d
Author:     Edward Tomasz Napierala <trasz@FreeBSD.org>
AuthorDate: 2021-04-13 11:38:37 +0000
Commit:     Edward Tomasz Napierala <trasz@FreeBSD.org>
CommitDate: 2022-02-13 21:06:37 +0000

    linux: adjust ordering of Linux auxv and add dummy AT_HWCAP2
    
    This should be a no-op; the purpose of this is to reduce
    a spurious difference between Linuxulator and Linux, to make
    debugging core dumps slightly easier.
    
    Note that AT_HWCAP2 we pass to Linux binaries is always 0,
    instead of being equal to 'cpu_feature2'.  This matches what
    I've observed under Ubuntu Focal VM.
    
    Reviewed By:    chuck, dchagin
    Sponsored By:   EPSRC
    Differential Revision:  https://reviews.freebsd.org/D29609
    
    (cherry picked from commit ca6e1fa3ce87f56847633530cb94a6fb63405680)
---
 sys/amd64/linux/linux.h            |  2 +-
 sys/amd64/linux/linux_sysvec.c     |  5 +++--
 sys/amd64/linux32/linux.h          |  2 +-
 sys/amd64/linux32/linux32_sysvec.c | 11 ++++++-----
 sys/compat/linux/linux_misc.h      |  1 +
 5 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/sys/amd64/linux/linux.h b/sys/amd64/linux/linux.h
index d343f920f6eb..cf9f5cccb287 100644
--- a/sys/amd64/linux/linux.h
+++ b/sys/amd64/linux/linux.h
@@ -88,7 +88,7 @@ typedef struct {
 /*
  * Miscellaneous
  */
-#define LINUX_AT_COUNT		19	/* Count of used aux entry types. */
+#define LINUX_AT_COUNT		20	/* Count of used aux entry types. */
 
 struct l___sysctl_args
 {
diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
index d4d7146ae224..ad1b286845df 100644
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -265,11 +265,11 @@ linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
 	    imgp->proc->p_sysent->sv_shared_page_base);
 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
+	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
 	AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
-	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
@@ -278,12 +278,13 @@ linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
 	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
 	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
 	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
-	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
 	AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary);
+	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0);
 	if (imgp->execpathp != 0)
 		AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp);
 	if (args->execfd != -1)
 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
+	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
 	AUXARGS_ENTRY(pos, AT_NULL, 0);
 
 	free(imgp->auxargs, M_TEMP);
diff --git a/sys/amd64/linux32/linux.h b/sys/amd64/linux32/linux.h
index e79d16e9e28a..244daba4b5c0 100644
--- a/sys/amd64/linux32/linux.h
+++ b/sys/amd64/linux32/linux.h
@@ -101,7 +101,7 @@ typedef struct {
 /*
  * Miscellaneous
  */
-#define	LINUX_AT_COUNT		20	/* Count of used aux entry types.
+#define	LINUX_AT_COUNT		21	/* Count of used aux entry types.
 					 * Keep this synchronized with
 					 * linux_fixup_elf() code.
 					 */
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
index 935d755e1904..c09d18675448 100644
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -199,10 +199,11 @@ linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
 	    M_WAITOK | M_ZERO);
 
 	issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
+	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux32_vsyscall);
 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
 	    imgp->proc->p_sysent->sv_shared_page_base);
-	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux32_vsyscall);
 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
+	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
 
 	/*
 	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
@@ -217,21 +218,21 @@ linux_copyout_auxargs(struct image_params *imgp, uintptr_t base)
 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
-	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
+	AUXARGS_ENTRY(pos, AT_BASE, args->base);
 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
-	AUXARGS_ENTRY(pos, AT_BASE, args->base);
-	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
 	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
 	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
 	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
 	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
-	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
+	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
 	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary));
+	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0);
 	if (imgp->execpathp != 0)
 		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp));
 	if (args->execfd != -1)
 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
+	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
 	AUXARGS_ENTRY(pos, AT_NULL, 0);
 
 	free(imgp->auxargs, M_TEMP);
diff --git a/sys/compat/linux/linux_misc.h b/sys/compat/linux/linux_misc.h
index da76753e3d24..bd8b2f3f63b4 100644
--- a/sys/compat/linux/linux_misc.h
+++ b/sys/compat/linux/linux_misc.h
@@ -88,6 +88,7 @@ extern const char *linux_kplatform;
 					 * differ from AT_PLATFORM.
 					 */
 #define	LINUX_AT_RANDOM		25	/* address of random bytes */
+#define	LINUX_AT_HWCAP2		26	/* CPU capabilities, second part */
 #define	LINUX_AT_EXECFN		31	/* filename of program */
 #define	LINUX_AT_SYSINFO	32	/* vsyscall */
 #define	LINUX_AT_SYSINFO_EHDR	33	/* vdso header */