From: Christophe Leroy christophe.leroy@csgroup.eu
[ Upstream commit 33e1402435cb9f3021439a15935ea2dc69ec1844 ]
bl;mflr is used at several places to get code position.
Use bcl 20,31,+4 instead of bl in order to preserve link stack.
See commit c974809a26a1 ("powerpc/vdso: Avoid link stack corruption in __get_datapage()") for details.
Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/c6eabb4fb6c156f75d56dcbcc6f243e5ac0fba42.162979176... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/misc.S | 2 +- arch/powerpc/kernel/misc_32.S | 2 +- arch/powerpc/kernel/misc_64.S | 2 +- arch/powerpc/kernel/reloc_32.S | 2 +- arch/powerpc/kexec/relocate_32.S | 12 ++++++------ 5 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S index 5be96feccb55..fb7de3543c03 100644 --- a/arch/powerpc/kernel/misc.S +++ b/arch/powerpc/kernel/misc.S @@ -29,7 +29,7 @@ _GLOBAL(reloc_offset) li r3, 0 _GLOBAL(add_reloc_offset) mflr r0 - bl 1f + bcl 20,31,$+4 1: mflr r5 PPC_LL r4,(2f-1b)(r5) subf r5,r4,r5 diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 6a076bef2932..b06f27501c25 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -67,7 +67,7 @@ _GLOBAL(reloc_got2) srwi. r8,r8,2 beqlr mtctr r8 - bl 1f + bcl 20,31,$+4 1: mflr r0 lis r4,1b@ha addi r4,r4,1b@l diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 4b761a18a74d..d38a019b38e1 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -255,7 +255,7 @@ _GLOBAL(scom970_write) * Physical (hardware) cpu id should be in r3. */ _GLOBAL(kexec_wait) - bl 1f + bcl 20,31,$+4 1: mflr r5 addi r5,r5,kexec_flag-1b
diff --git a/arch/powerpc/kernel/reloc_32.S b/arch/powerpc/kernel/reloc_32.S index 10e96f3e22fe..0508c14b4c28 100644 --- a/arch/powerpc/kernel/reloc_32.S +++ b/arch/powerpc/kernel/reloc_32.S @@ -30,7 +30,7 @@ R_PPC_RELATIVE = 22 _GLOBAL(relocate)
mflr r0 /* Save our LR */ - bl 0f /* Find our current runtime address */ + bcl 20,31,$+4 /* Find our current runtime address */ 0: mflr r12 /* Make it accessible */ mtlr r0
diff --git a/arch/powerpc/kexec/relocate_32.S b/arch/powerpc/kexec/relocate_32.S index 61946c19e07c..cf6e52bdf8d8 100644 --- a/arch/powerpc/kexec/relocate_32.S +++ b/arch/powerpc/kexec/relocate_32.S @@ -93,7 +93,7 @@ wmmucr: * Invalidate all the TLB entries except the current entry * where we are running from */ - bl 0f /* Find our address */ + bcl 20,31,$+4 /* Find our address */ 0: mflr r5 /* Make it accessible */ tlbsx r23,0,r5 /* Find entry we are in */ li r4,0 /* Start at TLB entry 0 */ @@ -158,7 +158,7 @@ write_out: /* Switch to other address space in MSR */ insrwi r9, r7, 1, 26 /* Set MSR[IS] = r7 */
- bl 1f + bcl 20,31,$+4 1: mflr r8 addi r8, r8, (2f-1b) /* Find the target offset */
@@ -202,7 +202,7 @@ next_tlb: li r9,0 insrwi r9, r7, 1, 26 /* Set MSR[IS] = r7 */
- bl 1f + bcl 20,31,$+4 1: mflr r8 and r8, r8, r11 /* Get our offset within page */ addi r8, r8, (2f-1b) @@ -240,7 +240,7 @@ setup_map_47x: sync
/* Find the entry we are running from */ - bl 2f + bcl 20,31,$+4 2: mflr r23 tlbsx r23, 0, r23 tlbre r24, r23, 0 /* TLB Word 0 */ @@ -296,7 +296,7 @@ clear_utlb_entry: /* Update the msr to the new TS */ insrwi r5, r7, 1, 26
- bl 1f + bcl 20,31,$+4 1: mflr r6 addi r6, r6, (2f-1b)
@@ -355,7 +355,7 @@ write_utlb: /* Defaults to 256M */ lis r10, 0x1000
- bl 1f + bcl 20,31,$+4 1: mflr r4 addi r4, r4, (2f-1b) /* virtual address of 2f */