Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | [PATCH] powerpc/32: Avoid link stack corruption in a few places | Date | Mon, 23 Aug 2021 07:52:45 +0000 (UTC) |
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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> --- arch/powerpc/kernel/misc_32.S | 2 +- arch/powerpc/kernel/reloc_32.S | 2 +- arch/powerpc/kexec/relocate_32.S | 12 ++++++------ 3 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index d8645efff902..d81e15a88a34 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 20,31,1f 1: mflr r0 lis r4,1b@ha addi r4,r4,1b@l diff --git a/arch/powerpc/kernel/reloc_32.S b/arch/powerpc/kernel/reloc_32.S index 10e96f3e22fe..5e9b58ae319e 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 20,31,0f /* 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..e25a5a9861ea 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 20,31,0f /* 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 20,31,1f 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 20,31,1f 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 20,31,2f 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 20,31,1f 1: mflr r6 addi r6, r6, (2f-1b) @@ -355,7 +355,7 @@ write_utlb: /* Defaults to 256M */ lis r10, 0x1000 - bl 1f + bcl 20,31,1f 1: mflr r4 addi r4, r4, (2f-1b) /* virtual address of 2f */ -- 2.25.0
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